Dan Margulis Applied Color Theory
Color Management in Private Book Publishing
Color Management in Private Book Publishing
Posted by: Mark Segal
Mon Jun 18, 2007 12:24 pm (PST)
Backcasts and Forecasts – or "Never Say
Never"?
Sometimes it's instructive to look back to the past and
measure progress against the forecasts of yester-year. Colour management is
one such instance. My hypothesis is that the science has made remarkable
progress relative to some of the prognosis less than a decade ago. Of
course forecasting dynamic stuff like the weather, the stock market and
technological change is fraught with risk, so we tend to be very forgiving
of our forecasters. We may recall that back in 1999 Dan didn't hold out too
much promise for colour management and instrument-generated ICC profiles in
pre-press (cf. "How Color Management Failed", Dan Margulis,
Electronic Publishing, July 1999).
Well, what's been happening since? It is instructive to
read what Michael Reichmann says about the technologies he used to produce
his recent book "Bangladesh – First Impressions". That
story is here: http://www.luminous-landscape.com:80/essays/100-books.shtml.
Michael showed me how he worked-up this material, I
have a copy of the book and I had an opportunity to compare quite a few of
his inkjet prints with the book reproductions - the proximity is uncanny,
making normal allowance for the inherent gamut differences between an
inkjet print and an offset reproduction; he markets the book for 30 bucks.
Readers can refer to the article hyperlinked above. For
convenience, here is a very brief selective bullet-point summary showing
how he used contemporary colour management solutions:
· Load the image in RGB 16-bit mode;
· Soft-proof using the printer profile supplied
by the press that will be printing the book;
· Correct colours in soft-proof mode with
gamut-warning toggled on; use adjustment layers to fine-tune saturation for
press conditions;
· When the on-screen image is satisfactory,
flatten, convert to 8-bit, convert to CMYK;
· Make an ink-jet hard proof using the proofer
profile and Epson Semi-matte 250.
The book was printed on a press in China. There was no
luxury of traveling to China for hand-holding the press-men. Reichmann
concludes: <With these techniques one can quite accurately control and
proof the book's images, both on screen and on paper. But …being able
to do this assumes that you have the right equipment….The critical
pieces include a good quality monitor that is properly calibrated and
profiled (*). ….You will also need a proper print viewing station (or
D50 light source). Put all of this together, and one can actually do a very
decent job of creating CMYK files for offset printing.(* As told on
Luminous-Landscape, Michael uses a colorimeter for calibrating and
profiling his monitor.)
More recently, my wife, who designs and makes jewelry
using exotic beads from ancient cultures, purchased a book published by
"Beadazzled" in Washington DC. Beadazzled is a family-owned
retailer of fine ethnic jewelry. The book, "Beadazzled Where Beads and
Inspiration Meet" also sells for 30 bucks and as befitting its subject
matter is a real gem. The quality of the photography and reproduction is
superb, as one would expect from the person who did it: William Allen,
formerly Editor-in-Chief of National Geographic Magazine. Bill undertook
this project in his private capacity after retiring from National
Geographic.
Bill explained to me how he did the photography and the
colour management for the press run:
<All the photos were made with the Canon 20D. I had
the cameras linked real-time to my computer to get an instant read on the
photos using the proprietary Canon Digital Photo Professional image capture
program. ………I worked with the printer to get the profiles
of the specific press that was to be used to print the book. As you know,
each press runs things a bit differently; so to get the absolutely most
accurate color, I wanted to match the color separations to the specific
press. I then made the final color separations through Photoshop CS using
those profiles plus some tweaks to the specifications that I knew from my
years at National Geographic……….I then went to Wisconsin
to run the job on press and reviewed all proofs and press pulls. Because of
all the work done in advance, the color proofs were remarkably on target.
We only had to make changes in three photos in the entire book. (By the
way, on two of the three that were missed… I sent the wrong
file)….. Believe me, that is quite remarkable on such a
project…… It's all well and good to run a job with numerous
proofs if money is no object. However, I find that money is virtually
always an object; so why not get to the same destination with less expense,
fewer frayed nerves, and save a few trees……
<The big difference that I see between the process
used by Michael and the process I used is that I never printed anything
here to determine accurate color before sending the file to the printer. I
sent the files to the printer (Worzalla) and had them do the proof. At the
beginning I sent them four files for them to proof. I looked at those
proofs and made small changes in my procedures when I made the balance of
the files. When the final color proofs were done, we were right on target.
I also cheated. I had the advantage of asking a couple of the best color
people in the business to review what I was doing and double-check the
first four or five of my files just to make sure that what I thought was
accurate would actually translate…….. The final job is as
accurate a color representation as I have seen on such a book….
Worzalla won a major printing award for that book.>
The importance of these examples is two-fold: firstly,
it demonstrates how using a scientifically colour-managed workflow
including 21st century hardware, software and profiles can yield a high
degree of accuracy at relatively modest cost regardless of the distance
between the press and the photographer. Secondly, because of this, it has
democratized the whole process of publishing fine-art books by putting this
technology into the hands of individual photographers and small enterprises
who can then produce very high quality output for sale at truly modest
prices.
Have things changed between 1999 and 2007?
Mark Segal
June 18, 2007
Note: Both Michael Reichmann and Bill Allen have seen
this material, know it is being submitted to the ACTL and agreed to be
quoted.
___________________________________________________________________________
Re: Color Management in Private Book Publishing
Posted by: "John Denniston"
Mon Jun 18, 2007 3:21 pm (PST)
Last week on The Online Photographer, Ctein described
the methods used to publish a book by Bill Atkinson and printed by Vanfu.
Bill waved his check book at the printer who agreed to profile a press
specifically to print his book. The process was long and costly but at the
end Bill had a book which Ctein says has the best colour reproduction of
any book he has every seen. Vanfu was impressed enough to convert their
regular production over to this method and have reaped considerable reward
since doing so. Obviously the truism that an offset press can't be
calibrated or profiled may not be true much longer.
On the other hand. My last experience with a printer,
last month, occurred when an artist whose work I photographed phoned me and
said her printer was having trouble with the files I gave her and that the
colours on the proofs were not even close and the printer was racking up
hours of time trying to correct them in CMYK. After describing what the
proofs looked like I told her to tell the printer to change his Photoshop
pref's so that it would honour embedded RGB profiles, which she did, and he
did, and the files printed perfectly with minimum adjustments.
When the printers I have to deal with become more like
Vanfu I will stop calibrating my monitor with Adobe Gamma and buy something
better. ;-)
For those who might want to read the story:
http:
//theonlinephotographer.com/the_online_photographer/blog_index.html
Regards,
John Denniston
www.johndenniston.ca
www.dirtbikephoto.com
___________________________________________________________________________
Re: Color Management in Private Book Publishing
Posted by: Mark Segal
Tue Jun 19, 2007 7:03 am (PST)
John,
Yes, as I mentioned in another thread just today, Bill
Atkinson's book was published in 2004 and he himself described the process
for getting it printed to his standards on pages 178 and 179. I agree with
you - it also demonstrates that a press can be calibrated and profiled. I
think what sets Bill's effort apart from the two that I described in
"Backcasts and Forecasts" is that the latter were inexpensive and
didn't involve the heavy overlays of intervention with printers and ink
suppliers that Bill's - truly impressive - effort required.
OK - while there are printshops and there are
printshops, you really do deserve something better than Adobe Gamma in this
day and age!
Mark Segal
___________________________________________________________________________
Re: Color Management in Private Book Publishing
Posted by: Dan Margulis
Fri Jun 22, 2007 12:47 pm (PST)
Mark Segal writes,
Sometimes it's instructive to look back to the past and
measure
progress against the forecasts of yester-year.
It absolutely is. This is one reason that I post so
many of my writings, and why we keep archives of this list.
We may recall that back
in 1999 Dan didn't hold out too much promise for colour
management
and instrument-generated ICC profiles in pre-press (cf.
"How Color
Management Failed", Dan Margulis, Electronic
Publishing, July 1999).
Anyone who recalls the article saying *that* may wish
to consider a checkup for incipient Alzheimer's ;-). But there is no need
to recall anything at all, as it is posted at
http://www.ledet.com/margulis/How_CM_failed.pdf
Since there is some question as to whether the article
was actually read before the above paragraph was posted, permit me to post
some quotations.
The description of the article at the above site reads,
"A year later [after Photoshop 5], an analysis of why the technology
was not (and would not) be adopted by service providers." The article
discusses not calibration, but the failure of the concept of embedded
profiles (the "ICC workflow") to establish a reliable way of
color communications, contrary to the prediction of AFAIK every authority
in the field slightly more than a year before. At that time, the debate had
been whether it was "a universal language of graphics" (Adobe's
term) that would be a boon to every user, however ignorant, or would be
valuable only to "a small minority of disciplined users" (my
term).
The theme of "universal language" appears in
the subhead of the column, and throughout. The opening paragraph likens it
to the artificial language Esperanto, which was heavily promoted in the
first half of the twentieth century as the universal language, to be
learned and spoken as a second language by all educated persons in the
world. I found the analogy to be quite close and continued it throughout
the column. I pointed out that while Esperanto is not dead--it's spoken by
more people than Hebrew or Lithuanian, for example--it certainly got
nowhere near the universal adoption that its propounders planned.
I wrote in 1999, "The *ICC workflow* is an
imprecise term. Many use it to signify the color equivalent of free love,
with all files bearing profiles and subject to conversion by strangers. An
ICC partisan, to me, is one who now or in the past has advocated this
sweeping approach....These people, in my view, are in denial: the ICC
workflow has gone the way of Esperanto. The legacy of the first PS 5
release is a minority who will never, ever, voluntarily embed profiles. The
group is big enough to forever ensure that the overall concept will
fail." That prediction looks like a pretty valid one from a 2007
perspective.
What Mark offers as an example of "modern"
practice consists of the projects of two different photographers who
desired to print books privately, using separate commercial printers. Each
was given an output profile by the printer or the printer's representative.
Using it, the two were able to get accurate monitor-to-print agreement and
were also able to set up their personal inkjet printers to produce accurate
proofs.
In this, the key piece is the printer's supplied
profile. If it was good, the rest is easy. If it was bad, the photographers
would have had to figure out how to make their own systems match it based
on incomplete information, which they may or may not have been able to do.
The point of Mark's initial sentence appears to be that
his examples are some kind of validation of instrument measurement to
create profiles--and yet there is no indication that instruments were even
used to produce either of these profiles, and if so to what extent they
were hand-tweaked afterward. As far as the end-users were concerned, they
fell out of the sky. Furthermore, one of these people explicitly went away
from the machine-generated profile (if that's in fact what it was). He saw
proofs, wasn't quite satisfied with the appearance, and proceeded exactly
as he would have in the 1980s: he summoned an experienced colleague (human
being, not a machine) to adjust the settings manually.
Personally, I don't care how the profiles were made. I
care whether they are good. This is consistent with what I wrote in 1999:
"Most ICC partisans nevertheless take the wholly illogical position
that profiles are only valid if a machine approves of them. As noted
earlier, color management boils down to making things look alike--not
measure alike. The success of a calibration is not determined by how much
time and money is thrown at it."
One participant in a recent thread was criticized for
using Adobe Gamma to calibrate his monitor. When I revealed some months ago
that I produced the ICC profile that governs my own monitor without the
dubious assistance of a machine, it was stated that it proved I was against
ICC color management. In view of these comments, I would have to say that
my 1999 statement holds up well.
Also, both these gentlemen appear to have approached
the problem in a serious, conscientious way, running tests, asking
questions, and responding to difficulties intelligently. The first, if I
read his explanation correctly, was not experienced with CMYK. He
understood in advance that there would be gamut problems, but he was
surprised to see how severe they were. When he found out, he did not become
frustrated, or demand that the printer match his out-of-CMYK-gamut colors,
or complain of an international conspiracy against photographers. He
decided to confront the problem directly and make the best of the
situation.
The second also was careful with his testing. When he
encountered a problem, as noted above, he sought expert assistance. The
stories of both projects are impressive. The question is, are the practices
of these two consistent with "a small minority of disciplined
users", or of "a universal language of color", accessible to
great and small?
It looks to me like the former, and that both put a
substantial amount of effort into their book, which no doubt was reflected
in the books' quality. They did not just calibrate their monitors, and
presto, beautiful color. As I wrote in 1999: "More than that, they
understand that such ridiculous claims are one of the major reasons for the
failure of the concept to date. Chris Murphy, a consultant who advocates
the use of ICC profiles, summed it up in April: 'The problem is that too
many people expect this to be pushbutton technology instead of a
commitment. There are a lot of people...that will tell you about their pain
to get to success but that they actually did make it to success, and it
works for them very well. This is not magic box technology.' It's that way
with traditional methods, too."
The importance of these examples is two-fold: firstly,
it
demonstrates how using a scientifically colour-managed
workflow
including 21st century hardware, software and profiles
can yield a
high degree of accuracy at relatively modest cost
regardless of the
distance between the press and the photographer.
The claims here are three: 1) a calibrated monitor; 2)
a means of calibrating an inkjet printer to a press in a foreign country;
3) a printer who is willing to provide an accurate guide for separation
setup.
Now, understanding that I was working for what was
likely the most state-of-the-art facility in the world at the time and so
was a few years ahead of most people, I first used a calibrated monitor to
eliminate contract proofs in 1981. By the end of that decade the entire
industry was on board. Calibration of monitors had been a non-issue for ten
years by the time my 1999 column appeared--any competently run facility was
not having any waste due to monitor issues.
I first calibrated a digital output device to match
output from a foreign press in, I believe, 1986, but possibly 1987,
definitely not 1988. There were never any remakes AFAIK due to inadequacies
of the proof. I am aware of several firms who were doing similar things in
the early 1990s.
I first gave an accurate guide for separation to a
client using RGB in 1988. By around 1993 I am aware of at least a dozen
firms that were doing the same.
Since then, there have obviously been advances, just as
there have been advances between Photoshop 2, which was what we were using
in 1993, and Photoshop CS3. The tools are faster and more flexible, and
easier for someone who does not have extensive experience in calibrating
equipment. They cannot, however, improve on a calibration that had
near-zero remakes.
So, if the suggestion of the opening paragraphs is that
my 1999 article predicted that such color-matching could never occur, this
is impossible, because all of it already *had* occurred, many years prior
to the article's publication.
Secondly, because of
this, it has democratized the whole process of
publishing fine-art
books by putting this technology into the hands of
individual
photographers and small enterprises who can then
produce very high
quality output for sale at truly modest prices.
I agree that the process has been considerably
democratized. To the extent that they make effective calibration easier,
machine-generated profiles presumably made a contribution, exactly as I
predicted in 1999. I wrote then, "Professional photographers, being
relatively quality-conscious, willing to invest time in learning, and
inexperienced in the vagaries of the CMYK colorspace, are the prime
beneficiaries. Although Photoshop's calibration features are free and an
ICC profile editor tends to cost $1,000 or more, it may be so much easier
for a photographer to learn and implement that it will justify the
expense."
However, it seems to me that calibration is one of the
smaller obstacles to achieving what others were achieving 10 or even 15
years ago. The biggest factor would have been the cost: the inkjet printers
that these guys have now are not just vastly better and vastly faster than
what would have been needed 10 or 15 years ago, they are vastly cheaper and
usable for other purposes besides contract proofing. Plus, that long ago,
before the advent of Google and similar tools, it would have been difficult
for these guys to hook up with overseas printers who could meet their
needs.
Above all, 15 or even 10 years ago, most photographers
were just scratching the surface of image manipulation; today many are
experts. All the calibration in the world doesn't help the reproduction of
bad images. I certainly hope that the people mentioned here produced good
ones, and that their books are successful. I close with this thought from
1999: "If you aren't getting accurate color, but want to, you could do
worse than starting by learning the ICC color model. With even a partial
understanding of it, you'll get good results. If you master it, though, you
will understand that all such systems are basically the same, and then you
can live with it if it suits you and without it if it doesn't. And you will
appreciate that it is no contradiction to say, color management is dead:
long live color management."
Dan Margulis
___________________________________________________________________________
Re: Color Management in Private Book Publishing
Posted by: Chris Murphy
Fri Jun 22, 2007 4:26 pm (PST)
On Jun 22, 2007, at 3:28 PM, Dan Margulis wrote:
I wrote in 1999, "The *ICC workflow* is an
imprecise term. Many use
it to signify the color equivalent of free love, with
all files bearing
profiles and subject to conversion by strangers. An ICC
partisan, to me, is one
who now or in the past has advocated this sweeping
approach....These people, in my view, are in denial:
the ICC
workflow has gone the way of Esperanto. The legacy of
the first PS
5 release is a minority who will never, ever,
voluntarily embed
profiles. The group is big enough to forever ensure
that the
overall concept will fail." That prediction looks
like a pretty
valid one from a 2007 perspective.
You can get a minority of people to actually believe
the moon is made of cheese. It's not a very interesting prediction to say a
minority will never voluntarily embed profiles. It's a vague prediction.
It's totally meaningless. Had Photoshop 5's color management instead looked
more like Photoshop 6, there'd still be a minority who would not embed
profiles.
InDesign CS2 has color management on by default and the
embedding of CMYK profiles on by default. And the same for Photoshop CS2
and Illustrator CS2. I haven't heard a whisper of a problem with these
defaults. It does in fact allow for the communication of both RGB and CMYK
color in the same document across workstations. So any prediction that wide
spread profile embedding would never occur is flat out wrong from a 2007
perspective. It has happened.
Chris Murphy
Color Remedies (TM)
New York, NY
___________________________________________________________________________
Re: Color Management in Private Book Publishing
Posted by: Stephen Marsh
Fri Jun 22, 2007 7:34 pm (PST)
Chris, are you referring to the locked "safe
CMYK" policy introduced in AID/AI CS2, I believe? I can't recall if it
is this or another policy that is "default" as I am not in front
of it to test.
If I understand things correctly, prior to this, if
there was a tag and the output intent of the job was different to the tag,
there was a colour conversion. The application was designed that way, to
consider profiles more critical than the files numbers, that it was fine to
convert between profiles as in theory the colour had the same LAB value but
with a different mix of numbers (this being the problem, colour build).
When using the "Safe CMYK" policy with the padlock symbol, file
values are not changed.
One can keep the CMYK tag for use in Photoshop, knowing
that InDesign and Illustrator will ignore it and output will not be screwed
up due to the image profile not matching the output profile.
Was not the inclusion of a "safe CMYK"
workflow in CS2 the result of negative user feedback? Did Adobe suddenly
"see the light", years after Photoshop 5 colour handling? Did
they get new consultants with press workflow experience? Compared to QXP,
AID is so much better, but at least QXP did not change files values by
default. The "safe CMYK" workflow policy of AID CS2 was long
overdue. It should have been obvious from the start to anybody with any
CMYK press workflow experience, that most print users don't want their
files values being messed with unless requested/agreed. The final files
numbers are that way for a reason, wanted/required, for right or wrong.
Nobody cared that their drop shadow was not "colorimetrically
correct", it was numerically correct - which provided the correct
print response and the desired visual response in a human observer. This is
fine for one off use in a known condition, but AID can use CM to repurpose
jobs on the fly, which used to be done as a separate task with separate
files. There is no doubt that CM can be of help in such cases, but one may
not wish this "help" as a general workflow - thus the "safe
CMYK" policy.
If you are referring to a "non safe CMYK"
workflow policy (any one that converts or does not have the padlock symbol
in colour settings) in AID or AI CS2, and that you have heard of no
problems with such a policy - then I would be surprised. This was a big
reason to move up from earlier versions, it made things safe and workable
for those that do wish to tag their CMYK files but do not wish this to have
a negative impact on output due to software design.
Sincerely,
Stephen Marsh.
___________________________________________________________________________
Re: Color Management in Private Book Publishing
Posted by: Ric Cohn
Sat Jun 23, 2007 9:20 am (PST)
On Jun 22, 2007, at 6:24 PM, Chris Murphy wrote:
It's not a very interesting prediction to say a
minority
will never voluntarily embed profiles. It's a vague
prediction. It's
totally meaningless. Had Photoshop 5's color management
instead
looked more like Photoshop 6, there'd still be a
minority who would
not embed profiles.
Now who's making vague predictions? <g> To me the
bottom line is my color management life would be easier today if Adobe had
adopted something closer to the current policies from the start. It's now
safe to maintain CMYK profiles on your own internal files as you pass them
between Adobe applications. The fact is that after PS5 came out even this
tiny piece of color management was not safe unless you really knew what you
were doing. I know I didn't, and today I shudder at the damage I caused my
own files by trying to follow what I understood of the process.
Compared to other's on this list, I exchange files with
only a very small number of people-- all of whom consider themselves
imaging professionals. What's amazing to me is that so far in 2007 I have
experienced 3 separate situations where I have been given untagged RGB
files. These are files from *supposedly* knowledgeable users who have gone
to the trouble of *removing* the attached profiles before passing on the
files! I have no idea why they think it's the right thing to do, but I do
know they have to do extra work to do this and so it's not a mistake. I
have even seen retouchers open these kinds of files, think the color looks
bad, and start correcting them to bring back the desired appearance. I
don't believe these are unusually stupid people. I do think this whole
subject is more difficult to understand than most color management
professionals acknowledge in their teachings.
If I can have so little confidence when I receive RGB
files, what should I think when I receive tagged, or untagged, CMYK files?
Ric Cohn
___________________________________________________________________________
Re: Color Management in Private Book Publishing
Posted by: André Dumas
Sat Jun 23, 2007 9:20 am (PST)
Hello Dan,
I agree with you that learning the ICC color model will
help anyone who whishes to get accurate color. I do reproduction of
watercolor originals on the very same papers used by the artist, Arches
watercolor paper, Fabriano etc., and getting an accurate reproduction is
essential. It cannot be done without accurate profiles at all stages of the
reproduction; Scanning (scanner profile), Viewing (monitor profile),
Printing (printer profile).
You say that "you will understand that all such
systems are basically the same" what does that mean ? Are there many
such systems and if so why is it important to understand that they are
basically the same? I use ICC and don't think that Photoshop would
recognize other models.
Then you say: "you can live with it if it suits
you and without it if it doesn't" I can't imagine anyone working on an
image for hours and *not* wanting to have it reproduced accurately. What do
you mean when you say that you can live without it if it doesn't suit you ?
I can't imagine anyone wanting inaccurate color.
André Dumas
___________________________________________________________________________
Re: Color Management in Private Book Publishing
Posted by: "Ron Kelly"
Sat Jun 23, 2007 11:31 am (PST)
Ric:
Our entire society, much moreso than most of us
realize, runs on confidence. We must have confidence in our base
assumptions to take risks. I'd like to build some more products, but it's
still a challenge to get them to the market looking as good as I'd like.
If they look good, they sell better and I prosper. If
they don't, I end up eating Kraft dinner instead of filet. Or worse.
How could we have more confidence in color management?
I've asked that question before here and elsewhere and it always sparks
cynical responses.
What we have is a competitive marketplace that is
endorsed for it's "efficiency". Never mind that it seems pretty
inefficient to ruin a job because something went wrong in color management.
Efforts to set universal standards with broad consensus
are a no-go in this environment because it's too socialistic. Practically
no one is willing to sacrifice their own short term business interests in
favor of the overall market progress.
There is no authority to regulate this across the
board.
What we have instead is continual attempts by the
market leaders to impose their vision on the industry. This, in turn, just
happens to coincide with their business plan to completely dominate the
industry, and for that reason, and a few others, there is always some
resistance to change.
Their spokespeople attack everyone with a contrary
opinion, calling them unscientific, out-of-date, uninformed, a dinosaur,
etc.
Therefore, we go round and round, and you can be
confident that this will continue.
When will this change? Perhaps when we've all joined
the Green Party and Dan conducts this list in Esperanto. I'm willing to
give it a try if you are.
Cheers,
Ron Kelly
___________________________________________________________________________
Re: Color Management in Private Book Publishing
Posted by: Chris Murphy
Sat Jun 23, 2007 11:32 am (PST)
On Jun 22, 2007, at 10:29 PM, Stephen Marsh wrote:
Chris, are you referring to the locked "safe
CMYK" policy introduced
in AID/AI CS2, I believe?
I'm referring to "North America General Purpose
2" color settings. Not any one color management policy. Those happen
to be the default in CS2 and CS3. In IDCS, color management was not on by
default.
One can keep the CMYK tag for use in Photoshop, knowing
that InDesign
and Illustrator will ignore it and output will not be
screwed up due
to the image profile not matching the output profile.
Output doesn't get screwed up due to the image profile
not matching the output profile. One doesn't inherently lead to the other.
It depends on the content of the image and the behavior of the printing
process. If rigorous process control is in place and registration is
excellent in most instances there would be no problem with such
repurposing. The areas where there can be a problem are well known but the
application lacks the granularity of control needed to isolate those areas,
and treat them differently than other areas. It's not an ICC problem, per
se.
Was not the inclusion of a "safe CMYK"
workflow in CS2 the result of
negative user feedback? Did Adobe suddenly "see
the light", years
after Photoshop 5 colour handling? Did they get new
consultants with
press workflow experience?
Like any rational company, I'm sure Adobe solicited
feedback from their customers and incorporated it. Since previous versions
of InDesign didn't have color management on by default, it's a big deal
that InDesign CS2 does have it on by default and tags each InDesign
document with both an RGB and CMYK profile and there has been not a wit of
a problem with it. Now both the Document profiles and the color management
policy have been embedded in the documents, making it much easier as things
go forward to know the intent, the color appearance, of the document.
Compared to QXP, AID is so much better, but
at least QXP did not change files values by default.
Neither did InDesign.
The "safe CMYK"
workflow policy of AID CS2 was long overdue. It should
have been
obvious from the start to anybody with any CMYK press
workflow
experience, that most print users don't want their
files values being
messed with unless requested/agreed. The final files
numbers are that
way for a reason, wanted/required, for right or wrong.
That we even still dealing with CMYK at the front end
at all is a testimony to how unsophisticated our applications, workflows,
and process control really are. Fine art photographic printing is routinely
done without access to 6+ channels of color data that will ultimately be
used to produce the image. The conversion from RGB to 6 + channel space
insulates the end-user entirely from having to deal with linearization, ink
limiting, black generation and increasingly also output sharpening. If a
print driver for something has complex as 8-color separations can be dealt
with in a fine art reproduction context, it can obviously be done with
4-colors. The problem isn't that there is a color management problem, it's
that there are realities of process control and registration beyond the
ability of applications and drivers to compensate for. Those who compel
their presses to behave with superb consistency are in fact able to take
advantage of such more complex yet more flexible workflows, and have been
doing so for years.
Nobody cared
that their drop shadow was not "colorimetrically
correct", it was
numerically correct - which provided the correct print
response and
the desired visual response in a human observer.
OK well a lot of people did care. In reality most
people don't care about the numbers, they care about color appearance. If
you talk to designers, ad agencies, any print buyer, they care about color.
They don't really care about the numbers it takes to get them what they
really want.
"Numerically correct" applies only to a
specific printing condition. As soon as they are using a different magenta,
or print on uncoated versus a #1 stock, those numbers have to be different.
Why? Because it's not the numbers that matter. It's the color appearance
that's important.
This is fine for one
off use in a known condition, but AID can use CM to
repurpose jobs on
the fly, which used to be done as a separate task with
separate files.
There is no doubt that CM can be of help in such cases,
but one may
not wish this "help" as a general workflow -
thus the "safe CMYK"
policy.
I don't know anyone who has ever advocated just
flipping a switch and suddenly that gets you full blown device independent
color management.
If you are referring to a "non safe CMYK"
workflow policy (any one
that converts or does not have the padlock symbol in
colour settings)
in AID or AI CS2, and that you have heard of no
problems with such a
policy - then I would be surprised.
That isn't a default. I do know many people who use
that workflow and the problems with respect to it are that it's still dyed
in the mold of tradition. It isn't flexible enough. There's only one output
profile that you can choose instead of multiple output profiles to account
for different amounts of black generation (or a smart black generation
model that doesn't depend on ICC profiles).
This was a big reason to move up
from earlier versions, it made things safe and workable
for those that
do wish to tag their CMYK files but do not wish this to
have a
negative impact on output due to software design.
There is still a negative impact to printing
"numbers" as-is to a printing process for which they weren't
designed. You just have a different problem than the ones you're alluding
to, a problem for which there is a solution that's been around for a long
time: get a proof, look at it, color correct the originals, rinse and
repeat until the proofing budget dries up or you like the proof. A lot of
people don't like such iterations anymore than others don't like black only
text in a TIFF turning into four color text.
Chris Murphy
Color Remedies (TM)
New York, NY
___________________________________________________________________________
Re: Color Management in Private Book Publishing
Posted by: "Ron Kelly"
Sat Jun 23, 2007 11:32 am (PST)
Andre:
Reproducing something as closely as possible could be
fairly considered an exercise in "accuracy".
In my work, for off-set, I am making commercially
saleable calendars. They start with photographs of course, and end up as
press ready CMYK files. This is vastly different to your situation, but I
feel compelled to comment because of the blanket nature of your statement
and your suggestion that doing things differently than you do is uncaring,
or sloppy.
I manipulate the originals for many reasons, but the
most important one is "what sells?" Therefore, I am not making
the reproduction "accurate" to what the original was.
I know you are thinking "that is not what I
meant".
The other reason why I don't just leave everything up
to profiles is, well, . . . they just aren't accurate.
For example, if I don't manipulate my blue skys, I'm
going to get purple calendars. I hate purple skys; I don't think I've ever
seen one but I've seen a ton of purple skys on printed matter.
I don't have the luxury of a press check for most of my
work, and I have to use the off-set company's press profile. Experience has
taught me to intervene regularly.
Yes, I have profiles in my workflow for monitor and
inkjet proofs and probably other places as well. Maybe my telephone.
It seems to me that there are two camps on this issue:
1. profiles are great, profiles are the future, use
profiles for everything everywhere all the time. If you get bad results
then switch to another company that honours profiles, has better ones, etc.
2. profiles are fine in many circumstances. Don't trust
profiles where experience and common sense suggest they can't be entirely
trusted, and don't waste time trying to make the perfect profile - it
doesn't exist.
I'm in camp 2.
It's not an all or nothing approach; I would say it's a
realist's approach.
Lastly, yes, I think we should all pay attention to
developments and adjust accordingly, in the event that things change.
Physics and business practices would have to change substantially for me to
move to camp 1, but I'll keep watching nevertheless.
Cheers,
Ron Kelly
___________________________________________________________________________
Re: Color Management in Private Book Publishing
Posted by: "Andrew Rodney"
Sat Jun 23, 2007 8:09 pm (PST)
On 6/23/07 11:15 AM, "Ron Kelly" wrote:
The other reason why I don't just leave everything up
to
profiles is, well, . . . they just aren't accurate.
For example, if I don't manipulate my blue skys, I'm
going to get purple
calendars. I hate purple skys; I don't think I've ever
seen one
but I've seen a ton of purple skys on printed matter.
I don't have the luxury of a press check for most of my
work, and
I have to use the off-set company's press profile.
Well you©ˆve explained clearly that the press
profile you©ˆre using from the press house isn©ˆt
accurate since you©ˆre not getting blue skies. Perhaps a profile
that provides the CMYK numbers based on what you©ˆre seeing in
RGB that are correct for blue?
Did the press change or was the profile incorrectly
built from day one is the question I©ˆd be asking.
Andrew Rodney
___________________________________________________________________________
Re: Color Management in Private Book Publishing
Posted by: André Dumas
Sat Jun 23, 2007 8:09 pm (PST)
Hello Ron,
In my case "what sells" must be accurate
colorwise. Not you?
I know what you mean about purple skies, if you look in
the archives of ACTL you will see that a few years ago I had a lot of
problems with that, and purple Holsteins cows, purple silos, purple
concrete. Thanks to the list and to the calibrationists those problems have
been solved.
I am also in camp 2. I was just saying that for
accurate watercolor reproduction, profiles are essential and after having
learned how to create *good* profiles then I find it that much easier for
my other photographic work to produce accurate prints that match what I see
on my display.
Nothing in my message that would suggest that doing
things differently is uncaring or sloppy.
André Dumas
___________________________________________________________________________
Re: Color Management in Private Book Publishing
Posted by: Mark Segal
Sun Jun 24, 2007 1:02 pm (PST)
Andrew,
I think this may be one - or two - of the fundamental
points at issue here, and it would be good if you could clarify. The
sentence which starts with "Perhaps....." seems to have ended-up
with something left out of it, so I don't quite understand what your
saying. But I'm inferring from the two questions you are asking that you
think a press house can build a profile that will - within the limits of
the press gamut - accurately provide the CMYK numbers that render the RGB
the photographer would see on a soft-proofed monitor using that profile,
and if so, I would go on to infer that any up-to-date press house most
likely uses current calibration and profiling technology to do so. Could
you comment on both these points?
Mark Segal
___________________________________________________________________________
Re: Color Management in Private Book Publishing
Posted by: "Ron Kelly"
Sun Jun 24, 2007 8:52 pm (PST)
André:
I guess I misunderstood you.
Ron Kelly
___________________________________________________________________________
Re: Color Management in Private Book Publishing
Posted by: "Andrew Rodney"
Sun Jun 24, 2007 8:52 pm (PST)
The poster mentioned that the profile supplied results
in blues that shift magenta, then he has to Œfix©ˆ the
resulting numbers to get correct blues. The profile is obviously not a good
one, it shouldn©ˆt be producing blues that shift. And fixing the
numbers is a lot more work and counter productive to just starting out with
a good profile that produces blues that look, well blue, not magenta.
This goes back to an old (and silly) post that the U.S.
Web Coated (SWOP) v2 profile always produces blues that print magenta. Yes,
if you send those numbers to a device the profile wasn©ˆt
properly built for, blues, reds, yellows, any color could shift. If you
send the right numbers to the right device, they don©ˆt. The U.S.
Web Coated (SWOP) v2 profile produces excellent blues when you send the
numbers to a device that follows TR001 of which the profile was built to
reflect.
This press house may have produced a poor profile (or
for that matter, used the wrong ink settings in the Custom CMYK settings in
Photoshop) or the profile might have been fine but the print conditions
changed. We don©ˆt know. We do know that there©ˆs an
issue with blues and the issue is most likely fixed by a better profile or
conversion process.
Without running the same set of color patches used to
build the original profile and then comparing the differences of newly
measured data, we don©ˆt know what the source of the blue problem
might be. If you did run the same patches and compared them to the original
data, we could at least see if there was device drift (if not, it might
have just started life out as a crappy profile). Either way, altering the
numbers of blues in Photoshop, while a solution seems like a heck of a lot
more work than simply starting out with the right RGB to CMYK conversion
instructions (profile).
Andrew Rodney
http://www.digitaldog.net/
___________________________________________________________________________
Re: Color Management in Private Book Publishing
Posted by: Stephen Marsh
Sun Jun 24, 2007 11:48 pm (PST)
Thanks for the reply Chris.
Chris Murphy wrote:
I'm referring to "North America General Purpose
2" color settings.
Not any one color management policy. Those happen to be
the default
in CS2 and CS3. In IDCS, color management was not on by
default.
OK, thanks for making that clear. Now let me be
clear[er than before].
The colour setting that you refer to does use the
"safe CMYK policy" by default (now that I have AIDCS2 in front of
me, I can confirm this).
In fact, all of the "2" presets use the
"ignore profile/honour values" method. It would appear that Adobe
agree with my position as a defalt. I am not saying this should never be
done (convert values), just that it is not a good default to convert CMYK
values just because two profiles don't match (which is my understanding of
CS or earlier workflow if enabling preserve CMYK profiles and there was an
image and document mode mismatch printing composite CMYK or CMYK seps).
Output doesn't get screwed up due to the image profile
not matching
the output profile.
This does not match the results from the test that I
have just performed using the colour management policy for "Preserve
Embedded Profile". This was the only colour managed colour option
before CS2 introduced the "safe CMYK Workflow", when using this
policy colours are converted if the image profile does not match the
document profile when printing/exporting to PDF.
My black only element (image) tagged with legacy Max
GCR was reseparated to SWOP v2 (document profile) when output when using
the preserve embedded CMYK profile option.
One doesn't inherently lead to the other.
It depends on the content of the image and the behavior
of the
printing process.
Please explain this further Chris.
If rigorous process control is in place and
registration is
excellent in most instances there would be no problem
with such
repurposing.
Qualified with a very big if Chris.
The areas where there can be a problem are well known
Indeed.
but the application lacks the granularity of control
needed to
isolate those areas, and treat them differently than
other areas.
It's not an ICC problem, per se.
This does not help things now Chris.
Like any rational company, I'm sure Adobe solicited
feedback from
their customers and incorporated it.
My point is that it should have been there since v1.0
Chris. My company did not move up to AID from QXP until AID CS2 *had* this
"safe CMYK workflow" policy.
Since previous versions of InDesign didn't have color
management on
by default, it's a big deal that InDesign CS2 does have
it on by
default and tags each InDesign document with both an
RGB and CMYK
profile and there has been not a wit of a problem with
it. <
I submit that there have been no problems becuase by
default these General Purpose 2 colour settings presets *use safe CMYK by
default* - so there will be no problems like I am talking of (unwanted
reseparation of CMYK elements based on their tag).
Are you saying that it would not be considered a
problem if one was using the "preserve embedded (CMYK) profile"
policy, imported a legacy Max GCR K only tagged file with K only elements
into a document profile of SWOP v2 and printed CMYK separations or
composite CMYK?
The solid K and tinted K image also with CMY areas
would come out as CMY with 90%K value where it only used to have K.
Now both the Document profiles and the color management
policy have
been embedded in the documents, making it much easier
as things go
forward to know the intent, the color appearance, of
the document. <
This does not overcome the issues that I have raised,
AFAIK.
Compared to QXP, AID is so much better, but
at least QXP did not change files values by default.
Neither did InDesign.
I must have misunderstood and taken the marketing hype
to heart then.
From Adobe: "Color management improvements Employ
a safe CMYK workflow by preserving CMYK color numbers all the way through
final output."
So Adobe thought it was an improvement to CM, to have
it dumbed down so that it would not change values. It may not have happened
by default, but it did happen with the right combination of settings as I
have listed above (and again below).
It did convert - if the CMYK document profile did not
match the image profile if using the preserve ICC profile option and not
"safe CMYK", the image was reseparated to the document
destination, using the embedded tag as a source when printing to composite
CMYK or separations.
That we even still dealing with CMYK at the front end
at all is a
testimony to how unsophisticated our applications,
workflows, and
process control really are.
Is having precise control unsophisticated?
This is what working in final device space with no
conversions give those that require it - precise control.
This segment of your reply is moving past the point I
was making. It can be addressed in a different post if required - I don't
wish to muddy things up more than they are at the moment.
Fine art photographic printing is routinely done
without access to
6+ channels of color data that will ultimately be used
to produce the
image. The conversion from RGB to 6 + channel space
insulates the
end-user entirely from having to deal with
linearization, ink
limiting, black generation and increasingly also output
sharpening. If
a print driver for something has complex as 8-color
separations can be
dealt with in a fine art reproduction context, it can
obviously be
done with 4-colors.
Even in such conditions, it can sometimes help to work
in CMYK (even if the RIP is CcMmYK). I have had one specific problem with
inkjet colour builds for dark coloured areas in one job that I recall and
the only thing that helped was a CMY only separation so that the RIP would
not lay down any K at all and only use CcMmY for this area (a persons face
in shadow under a hat brim).
This segment of your reply is moving past the point I
was making. It can be addressed in a different post if required - I don't
wish to muddy things up more than they are at the moment.
The problem isn't that there is a color management
problem, it's
that there are realities of process control and
registration beyond
the ability of applications and drivers to compensate
for. Those who
compel their presses to behave with superb consistency
are in fact
able to take advantage of such more complex yet more
flexible
workflows, and have been doing so for years.
If you still hold this position, despite my examples
above, then we will have to agree to disagree on where the problem lies
Chris.
Nobody cared that their drop shadow was not
"colorimetrically
correct", it was numerically correct - which
provided the correct
print response and the desired visual response in a
human observer.
OK well a lot of people did care. In reality most
people don't care
about the numbers, they care about color appearance.
Please reread my post, the numbers with the stock/ink
etc are the desired colour appearance they "care" for.
If you talk to designers, ad agencies, any print buyer,
they care
about color. They don't really care about the numbers
it takes to get
them what they really want.
I am/have been some of the above (designer, agency
worker) - and I am also prepress too.
They do if a profile or human chooses inappropriate
numbers, as in this thread:
http:
//tech.groups.yahoo.com/group/colortheory/message/18079
I will agree that sometimes appearance matters most,
other times numbers matter most. Both rely on correct or good numbers.
"Numerically correct" applies only to a
specific printing condition.
That is all that I am talking of Chris.
As soon as they are using a different magenta, or print
on uncoated
versus a #1 stock, those numbers have to be different.
Why? Because
it's not the numbers that matter. It's the color
appearance that's
important.
Yes, agreed - but this has no bearing on the workflow
of a user for a single condition that does not understand why their colour
builds are magically being changed at output to print or PDF, because their
image has a different profile to the document and they are printing
seps/comp 4C with a preserve embedded profile policy.
If you are referring to a "non safe CMYK"
workflow policy (any one
that converts or does not have the padlock symbol in
colour settings)
in AID or AI CS2, and that you have heard of no
problems with such a
policy - then I would be surprised.
That isn't a default.
Really, are you sure Chris?
When I load in the preset for North America General
Purpose 2 - guess what is in the CMYK field? It is the safe value locked
preserve numbers option, not preserve profile (alter colour values).
I do know many people who use that workflow and the
problems with
respect to it are that it's still dyed in the mold of
tradition. It
isn't flexible enough.
This is why it is used, these users just want the same
numbers to come out as go in, they are not repurposing the job. If they do,
they will dupe it and do it manually as a second file marked for that new
condition.
Sometimes one can be so flexible that things get bent
out of shape!
There's only one output profile that you can choose
instead of
multiple output profiles to account for different
amounts of black
generation
Not a real concern, in Photoshop the images are put in
their correct GCR etc. All the files are preped for this one condition,
they can have any profile and the safe CMYK workflow option will ensure
that the numbers remain that way, while one can take advantage of the ICC
profile in Photoshop.
(or a smart black generation model that doesn't depend
on ICC
profiles).
This segment of your reply is moving past the point I
was making. It can be addressed in a different post if required - I don't
wish to muddy things up more than they are at the moment.
There is still a negative impact to printing
"numbers" as-is to a
printing process for which they weren't designed.
This is a distraction, I did not make this point, I am
only talking output for a single condition, that the file was originally
prepared for.
This segment of your reply is moving past the point I
was making. It can be addressed in a different post if required - I don't
wish to muddy things up more than they are at the moment.
You just have a different problem than the ones you're
alluding to,
a problem for which there is a solution that's been
around for a long
time: get a proof, look at it, color correct the
originals, rinse and
repeat until the proofing budget dries up or you like
the proof. A lot
of people don't like such iterations anymore than
others don't like
black only text in a TIFF turning into four color text.
Agreed Chris.
Sincerely,
Stephen Marsh.
___________________________________________________________________________
Re: Color Management in Private Book Publishing
Posted by: Ric Cohn
Mon Jun 25, 2007 7:31 am (PST)
On Jun 24, 2007, at 7:16 PM, Andrew Rodney wrote:
altering the numbers of blues in Photoshop,
while a solution seems like a heck of a lot more work
than simply
starting out with the right RGB to CMYK conversion
instructions (profile).
Andrew,
Obviously yes-- and sometimes no. If a printer tells
you to use US Webcoated (or Sheetfed) Swop (V2), as this is what they aim
for, I'd say there is a chance that they really do. If you know for sure
that this is the case you can *generally* convert and move on.
Unfortunately, unless you know for sure that they
really do *and* that they have excellent process control it may make sense
to take some precautions. Dan has shown very clearly in his book- with
printed examples- and on this list- with CMY numbers- that US Webcoated
Swop (V2) puts more magenta into blues in the range of skies than any other
profile he's looked at. I confirmed this with 2 SWOP profiles I have access
to that are used by 2 different large Ad Agencies for their conversions.
These agencies prepare magazine ads for some of the largest, and pickiest,
clients in the world. Obviously, they prepare one file for magazine repro
and the magazines need to match their proofs or they don't get paid. If the
skies come out consistently purple they have huge clients complaining. Why
do you think they don't use the canned profile(s) in Photoshop? These
internal agency profiles aren't "custom" profiles in the sense
that they were prepared to match a particular press. They are custom
profiles in the sense that they have been custom built to better match
their output needs from presses that conform to SWOP or GRACOL or they
don't get paid. My guess is that they have been built with better fudge
factors for the realities of presses.
If a slightly CYAN sky would be preferable to a
slightly PURPLE sky then why, as a color management consultant, are you so
loath to admit that pulling a little magenta out of the skies is a
reasonable precaution to recommend? There are some colors which if they
change slightly in one direction are rarely a problem (skies going more
cyan, skin going more yellow) and if it changes in the other direction is
more likely to be a problem (skies going purple, skin going blue). There
are also situations where the exact same colors (if they are not skies or
skin, for example) will not matter to anybody if they make the same shift.
This is where human intervention still makes sense and where I honestly
can't understand your resistance to acknowledging what I see as the
realities of press reproduction. Please explain.
When I am supplied a true custom profile by a printer I
take it much more seriously. However, I still think it makes sense to look
at the individual image and see if there are colors that if they vary in
one direction are a problem and in the opposite direction would be less of
a problem and to adjust accordingly. What are your thoughts on this?
Ric Cohn
___________________________________________________________________________
Re: Color Management in Private Book Publishing
Posted by: Dan Margulis
Mon Jun 25, 2007 7:33 am (PST)
Andre writes,
I do reproduction of watercolor
originals on the very same papers used by the artist,
Arches
watercolor paper, Fabriano etc., and getting an
accurate reproduction
is essential. It cannot be done without accurate
profiles at all
stages of the reproduction;
If you are using "profiles" in the sense that
I do, agreed. If you are intending "profiles" to mean
machine-generated ICC profiles only, then it would appear you are saying
that this type of work could not have been done before 2002 or whatever
arbitrary date you might choose for the time when such profiles became
marginally acceptable.
You say that "you will understand that all such
systems are basically
the same" what does that mean ? Are there many
such systems and if so
why is it important to understand that they are
basically the same?
I use ICC and don't think that Photoshop would
recognize other models.
The problem of getting an accurate match to one's
screen and/or hard proof is much older than the ICC. The problem did not
change because the ICC specification was propounded, the methods of solving
it did not change, and the means of judging it did not change. The idea of
taking measurements and generating a profile from them was already
implemented before the ICC itself was even formed.
There are only two novelties in the ICC approach.
First, the presence of an embedded profile that was intended to facilitate
communication between strangers; second, the introduction of a file format
that can readily be exchanged between devices instead of a large number of
proprietary formats. The first was a disastrous failure that caused great
damage to the industry. The second was a great success that has empowered
many users to achieve matches that previously would have required the
services of an expert. The difference between the two should be understood,
and we should also understand that the underlying means of calibration
never changed.
Then you say: "you can live with it if it suits
you and without it if
it doesn't" I can't imagine anyone working on an
image for hours and
*not* wanting to have it reproduced accurately. What do
you mean
when you say that you can live without it if it doesn't
suit you ?
To answer this all you need do is ask yourself what
would happen tomorrow if you woke up and found that your profiles no longer
functioned. Further, that those who say that any form of color management
that is not ICC color management is not a form of color management had so
irritated God that He in His vengeance had disabled all spectrophotometers,
except for those used by His righteous servants for the purposes of
verifying, not establishing, calibration. What would you do?
This is not a very difficult question. There are many
ways to achieve the same thing. Today, most likely one would calibrate the
monitor using Apple's internal calibrator, which is quite powerful IMHO.
The other conversions could be handled by Photoshop Actions, which have all
the power of ICC profiles and then some.
An experienced person who did something like this in
1999, when my column was written, would certainly have gotten a more
accurate result than using pure instrument-based profiles, which were, at
that time, appallingly poor. Today, they're doubtless much better, although
I haven't tested any in several years. There's also the possibility of some
hybrid that uses a little of both methods for conversions, or the
possibility of adopting, say, eyeball monitor calibration but
computer-generated scanner profiling and hand-tweaked output profiling
loosely based on machine measurements.
Lots and lots of different ways to achieve the same
result. I don't recommend
adopting one based on political correctness, but rather
on whether it gets a
good result, how much time it takes to get to that
result, and how easy it is
for somebody without much experience in calibration to
proceed.
Dan Margulis
___________________________________________________________________________
Re: Color Management in Private Book Publishing
Posted by: "Terry Wyse"
Mon Jun 25, 2007 4:16 pm (PST)
Seems it's time once again for the bi-annual flogging
of "calibrationists" and those who ascribe to the notion that
embedding profiles may in fact be a good and helpful thing to those
downstream of the image creator.
My position has always been...
* Embedding profiles/tagging RGB images is a must.
Period. I can't see how anyone could make a case otherwise.
* Embedding profiles/tagging CMYK images is at least
helpful. It is helpful if the image is being handed off to a PROFESSIONAL
and is only potentially dangerous if handed off to a non-professional that
has their color management policies set incorrectly. Even in this case, I
would still contend that this non-pro will find a multitude of OTHER ways
to "damage" an image even if the image is untagged. Even so, if
their default CMYK working space is correct for their printing process and
a "blind" or unintended conversion takes place as a result of a
profile tag, this conversion is potentially less "destructive"
than blindly sending the original CMYK values straight to press (try
sending a "SWOP" separation to a press running newsprint and see
what you get!).
But what I really wanted to chat about was the fact
that profile conversions at prepress and print shops have been going on for
quite some time whether folks on this list realize it or not. And I believe
this will become even MORE prevalent in the future for one simple reason:
INK SAVINGS. Let me explain...
It's a fact of life that this has been going on in the
newspaper industry for a while. For them it's all about dealing with
separations that have been incorrectly separated for "SWOP" print
conditions where the total ink amount is way in excess of what they can
print reliably. A separation with 300% total ink is simply not going to fly
for a process that can't handle much more than 220%. So to combat this,
newspaper prepress departments will generally have some sort of profile
conversion (typically device links) that not only correct for total ink but
almost by definition will perform a profile conversion/re-separation in the
process. My guess is that most will assume SWOP TR001 for untagged CMYK
which could possibly result in less-than-ideal color as opposed to
supplying tagged CMYK. This is assuming of course that their device
link/ink reduction conversion has the option of honoring embedded profiles
and that they have the option enabled.
This same technology is now finding it's way into
publication and even commercial sheetfed printing where ever tightening
margins have forced them to find ways to reduce cost. At some medium to
large printers, ink cost alone can be anywhere from several hundred
thousand to in the millions annually. A (conservative) 15% ink savings can
be real money for these people. The icing on the cake for this technology
is that it also provides a very simple method of achieving conformance to
print standards and specifications such as the relatively new G7 GRACoL and
G7 SWOP. At the very least, it's quite a bit more sophisticated than using
simply plate/press curves to meet these specifications.
Bottom line, I believe you're going to see MORE in
terms of taking customer-supplied images and converting them using either
straight ICC profiles, device link profiles or proprietary conversions of
one form or another and it's just going to become another part of prepress
workflow in the same way that auto-trapping has become over the past 10-15
years. At the end of the day, quality on press is going to be about color
and matching a standard proof specification (here in the US, that will
likely be "G7" GRACoL and/or SWOP) and not someone's notion of
their sacred CMYK values.
Regards,
Terry Wyse
_____________________________
WyseConsul
Color Management Consulting
G7 Certified Expert
704.843.0858
http://www.wyseconsul.com
http://www.colormanagementgroup.com
___________________________________________________________________________
Re: Color Management in Private Book Publishing
Posted by: "Terry Wyse"
Mon Jun 25, 2007 4:16 pm (PST)
It's fairly meaningless to talk of "SWOP"
profiles without some sort of reference to where the measurement data came
from. OTHOH, if one took the now dated TR001 characterization data and
built a couple of profiles using different profiling software and/or gamut
mapping options and then compare these to Photoshop's
"USWebCoated(SWOP)v2", then you'd have a meaningful comparison.
But to compare profiles built from different "SWOP" data sets is
meaningless.
I'm guessing here but I suspect that some of this
notion of "too purple" skies from Photoshop's SWOP profile comes
from folks that may have been using profiles created from proofing systems
(Matchprint, Kodak Approvals, etc.) and not REAL press data like the
Photoshop profile created from TR001 press data. Let me explain:
Analog and virtually any (non-color managed) digital
dot-proofing system "suffers" from having near-perfect "wet
ink trap" characteristics. In other words, overprinting solids
"trap" with near perfect efficiency. In the case of C+M
overprints, these would have a relatively purple bias since the magenta
colorant is going to overprint cyan perfectly and not show the relative
loss of trapping efficiency as you'd have on a press with the typical KCMY
(magenta over cyan) ink sequence. A profile made from such a proofing
system would compensate for this natural purple bias by reducing the amount
of magenta ink when overprinting cyan ink during the CMYK conversion. When
this goes to press however, this C+M combination would tend to shift
towards cyan due to the less efficient wet ink trap of the printing press.
By the same token, a profile made from REAL press data such as TR001 would
see the less efficient overprint characteristic of magenta over cyan and
compensate by adding relatively more magenta in blues. Make sense?
My advice to anybody concerned that this is an issue
but still wants to produce "SWOP" separations, they should go to
either www.gracol.org or www.swop.org and download the latest
"G7" family of profiles. Theirs one flavor of GRACoL for Paper
Type 1 (commercial sheetfed on typical gloss coated paper) and there's two
flavors of SWOP, one for Paper Type 3 (a neutral white coated publication
paper) and one for Paper Type 5 (dirty yellow publication paper, same as
TR001). The SWOP2006_Coated3 profile is essentially the new default SWOP
profile and should be considered a replacement for Photoshop's supplied
SWOP profile. I can tell you that these are VERY GOOD profiles all made
from real press data. If you just can't leave well enough alone, you can
also download the characterization data that was used to build these
profiles and roll your own profile, provided you own a profiling
application that will accept standard CGATS data.
Regards,
Terry Wyse
_____________________________
WyseConsul
Color Management Consulting
G7 Certified Expert
704.843.0858
http://www.wyseconsul.com
http://www.colormanagementgroup.com
___________________________________________________________________________
Re: Color Management in Private Book Publishing
Posted by: "Andrew Rodney"
Mon Jun 25, 2007 4:17 pm (PST)
On 6/25/07 7:25 AM, "Ric Cohn" wrote:
Obviously yes-- and sometimes no. If a printer tells
you to use US
Webcoated (or Sheetfed) Swop (V2), as this is what they
aim for, I'd
say there is a chance that they really do.
One would hope yes.
If you know for sure that
this is the case you can *generally* convert and move
on.
Unfortunately, unless you know for sure that they
really do *and*
that they have excellent process control it may make
sense to take
some precautions.
Such as?
Dan has shown very clearly in his book- with
printed examples- and on this list- with CMY numbers-
that US
Webcoated Swop (V2) puts more magenta into blues in the
range of
skies than any other profile he's looked at.
So what, it doesn't make it right (he's wrong, I can
tell you this from experience sending data to output devices that DO
conform to TR001. That Dan hasn't seen other CMYK profiles that exhibit
this behavior doesn't make what he's saying correct because its not. I also
don't know that Dan has enormous experience working with all nature of CMYK
ICC profiles.
But this is easy to test as I've done. Trick is finding
someone's who's press or proofing system does indeed conform to TR001 and
send a blue sky to this device. Lots and lots of users have done this
without skies going magenta!
If the skies come
out consistently purple they have huge clients
complaining. Why do
you think they don't use the canned profile(s) in
Photoshop?
Why don't they use the correct press conditions? That
is, right being a press condition that the profile was built for.
These internal agency profiles aren't
"custom" profiles in the sense that
they were prepared to match a particular press. They
are custom
profiles in the sense that they have been custom built
to better
match their output needs from presses that conform to
SWOP or GRACOL
or they don't get paid. My guess is that they have been
built with
better fudge factors for the realities of presses.
Maybe but it appears if you're saying they have an
issue with blue. I suspect this is a profile issue but it could be user
error elsewhere in the process. But the idea that an ICC profile always
produces a blue shift is simply not correct and silly. Now if every printed
piece shifted to blue, OK, we'd have something to discuss. Clearly this
isn't happening.
Andrew Rodney
___________________________________________________________________________
Re: Color Management in Private Book Publishing
Posted by: André Dumas
Mon Jun 25, 2007 9:41 pm (PST)
Ric your message reminds me of my battle in past with
purple skies and purple galvanized metal silos, etc.
So at one point Stephen Marsh mentioned that a lack of
yellow could be "one" of the culprits, and *that* solved many of
my problems with blues turning purple.
André Dumas
___________________________________________________________________________
Re: Color Management in Private Book Publishing
Posted by: "Mike Russell"
Tue Jun 26, 2007 1:28 am (PST)
This is obviously the Old Testament God. Accordingly, I
would ditch my spectrometer and ColorChecker, head for the hills, and
dearly hope not to be smitten.
Thanks, Dan, for another elucidating description of the
current state of affairs.
Mike Russell - www.curvemeister.com
___________________________________________________________________________
Re: Color Management in Private Book Publishing
Posted by: Stephen Marsh
Tue Jun 26, 2007 1:28 am (PST)
André Dumas wrote:
So at one point Stephen Marsh mentioned that a lack of
yellow could
be "one" of the culprits, and *that* solved
many of my problems with
blues turning purple.
André, can you dig up the quote, I am not sure
that was me! Perhaps you just attribute this statement to me, going from
memory, when it was not me who said that?
Saturated blue turning purple is usually due to too
much magenta, yellow desaturates blue and add enough and you get green mud
(one often reduces or removes any yellow in saturated blues).
It has been pointed out that many profiles use LAB as
the PCS and LAB has problems with some hue angles in out of gamut colours -
for OoG blues, this is often ending up with too much magenta in the final
separation. The colour is out of gamut, so it is up to a profile or human
to come up with workable numbers - as the numbers do not exist for this
colour. Sadly, the profiles that offer too much magenta for OoG blue tend
to go mauve.
This is a problem for deep saturated blues in CMYK
(yes, an oxymoron) - but is also often an issue for lighter tints of blue,
where one has to be even more careful with the ratio of M to C in light
pastel type blues.
Sincerely,
Stephen Marsh.
___________________________________________________________________________
Re: Color Management in Private Book Publishing
Posted by: "Lee Clawson"
Tue Jun 26, 2007 7:04 am (PST)
on 6/25/07 11:41 AM, Terry Wyse
By the same token, a profile made from REAL
press data such as TR001 would see the less efficient
overprint
characteristic of magenta over cyan and compensate by
adding relatively more
magenta in blues. Make sense?
Makes sense to me. Better yet this is the first time it
does. That alone is a good reason to have this come up at least twice a
year.
Lee Clawson
2/\V/\7 Studio
___________________________________________________________________________
Re: Color Management in Private Book Publishing
Posted by: André Dumas
Tue Jun 26, 2007 7:51 pm (PST)
Hello Stephen,
I can't find any message where you said that, so I'm
sorry I must have you mixed up with somebody else.
But someone did send me a message to that effect and
now I remember that at the time we were talking about galvanized farm
structures and concrete wall with a purplish cast and I also remember that
the addition of yellow improved those and it also had a positive effect on
people skin tones better than just the removal of magenta.
André Dumas
___________________________________________________________________________
Re: Color Management in Private Book Publishing
Posted by: André Dumas
Tue Jun 26, 2007 7:51 pm (PST)
DMargulis. wrote:
If you are using "profiles" in the sense that
I do, agreed. If you
are intending "profiles" to mean
machine-generated ICC profiles only,
then it would appear you are saying that this type of
work could not
have been done before 2002 or whatever arbitrary date
you might
choose for the time when such profiles became
marginally acceptable.
We know that the reproduction of original watercolor
art can be done and *has been* done in the past but I simply meant that
with my limited abilities I don't think that I would have even thought
about doing it without the help of modern profiling software and hardware.
The problem of getting an accurate match to one's
screen and/or
hard proof is much older than the ICC. The problem did
not change
because the ICC specification was propounded, the
methods of solving
it did not change, and the means of judging it did not
change. The
idea of taking measurements and generating a profile
from them was
already implemented before the ICC itself was even
formed.
I hear you Dan, but it was solely the domain of highly
skilled individuals and not available to people like me. The ICC is a
perfection of what you mention thought out in terms of an evolution
toward new *standards* of production.
These new techniques and tools allow me to express my
creativity in ways that would have been impossible without them, they are
liberating. Like the computer and powertools etc.
André Dumas
___________________________________________________________________________
Re: Color Management in Private Book Publishing
Posted by: Chris Murphy
Wed Jun 27, 2007 6:39 am (PST)
Dan Margulis wrote:
There are only two novelties in the ICC approach.
First, the presence of an
embedded profile that was intended to facilitate
communication between strangers;
Not true. PostScript allowed the embedding of Color
Space Arrays, which described the source profile and was supported in EPS.
Since you count embedding to be a novelty, then there are many other
attributes of ICC profiles that quality.
second, the introduction of a file format that can
readily be
exchanged between devices instead of a large number of
proprietary
formats.
ICC profiles aren't exchanged between devices.
The first was a disastrous failure that caused great
damage to the
industry.
To be clear it was not the embedding of profiles that
was the problem, even though you continue to repeat it after being
corrected numerous times now. An ICC profile is metadata. It's like the
date stamp on a file, or who created it. It's just data. It doesn't change
or affect any other data in the file.
Do you have a metric for what qualifies as "great
damage"? Do you have a dollar figure for this great damage? I'll bet
make-ready waste makes this "embedded profile disaster" pale in
comparison. I think you claim of "great damage" is over hyped.
And in any event, in case you haven't noticed, it's not 1995 anymore, so
you really should put this problem to bed. It's not a failure because it is
being used with regularity, and by default.
The second was a great success that has empowered many
users to
achieve matches that previously would have required the
services of
an expert. The difference between the two should be
understood, and
we should also understand that the underlying means of
calibration
never changed.
Except that ICC profiles aren't a means to calibrate
anything. Calibration is a pre-requisite for building an ICC profile. ICC
profiles, WCS profiles, any kind of color profile for a device, is
characterization.
To answer this all you need do is ask yourself what
would happen tomorrow if
you woke up and found that your profiles no longer
functioned. Further, that
those who say that any form of color management that is
not ICC color
management is not a form of color management had so
irritated God
that He in His vengeance had disabled all
spectrophotometers,
except for those used by His righteous servants for the
purposes of
verifying, not establishing, calibration. What would
you do?
Nothing like a little hyperbole, eh? Profiles no longer
functioned? OK then...
This is not a very difficult question. There are many
ways to achieve
the same thing. Today, most likely one would calibrate
the monitor
using Apple's internal calibrator, which is quite
powerful IMHO. The
other conversions could be handled by Photoshop
Actions, which have
all the power of ICC profiles and then some.
You've got a way to convert an RGB image to CMYK, with
output specific gamut and tone mapping, without using an ICC profile in
Photoshop?
Chris Murphy
Color Remedies (TM)
New York, NY
___________________________________________________________________________
Re: Color Management in Private Book Publishing
Posted by: Chris Murphy
Wed Jun 27, 2007 6:39 am (PST)
On Jun 25, 2007, at 2:41 AM, Stephen Marsh wrote:
In fact, all of the "2" presets use the
"ignore profile/honour values"
method. It would appear that Adobe agree with my
position as a defalt.
It ignores embedded profiles in placed CMYK objects.
Everything else is tagged. And by default those CMYK objects, usually from
Illustrator or Photoshop, are tagged. The InDesign document is tagged.
Color appearance is preserved through the embedding of these profiles. It's
been going on for two years.
I am not saying this should never be done (convert
values), just that
it is not a good default to convert CMYK values just
because two
profiles don't match (which is my understanding of CS
or earlier
workflow if enabling preserve CMYK profiles and there
was an image and
document mode mismatch printing composite CMYK or CMYK
seps).
Yes but this wasn't a default behavior.
This does not match the results from the test that I
have just
performed using the colour management policy for
"Preserve Embedded
Profile". This was the only colour managed colour
option before CS2
introduced the "safe CMYK Workflow", when
using this policy colours
are converted if the image profile does not match the
document profile
when printing/exporting to PDF.
Yes the colors are converted. But again, that is not
synonymous with output getting screwed up.
My black only element (image) tagged with legacy Max
GCR was
reseparated to SWOP v2 (document profile) when output
when using the
preserve embedded CMYK profile option.
This is an example of one of the known areas where
repurposing CMYK is problematic. There are ways color management allows the
source and destination to be different, repurpose the colorimetric aspects
while preserving things like black channel behavior. Now when it comes to
black generation this is a problem because there's no agreed upon metric
for amount of black generation, and then how to associate that information
with a CMYK image.
There are some ideas on how to deal with this problem,
but there are so many hands in the pot at once that I don't know that it's
really resolvable. We need a certain kind of image metadata to describe
either the black generation or the classify the image (i.e. screen- shot)
and then we need support for multiple output device profiles, each one also
needs a tag to say how much black generation it uses, and then applications
that see a high kgen image and know to repurpose only using a high kgen new
destination profile. It's complex. It would be easier to get farm animals
to square dance.
One doesn't inherently lead to the other.
It depends on the content of the image and the behavior
of the
printing process.
Please explain this further Chris.
In your example the separation color appearance
actually is correctly preserved. Black generation for the image type is now
wrong, but that's primarily due to compensating for poor register or
process control press side. If it were very good, the colorimetric
equivalent would work equally well.
If rigorous process control is in place and
registration is
excellent in most instances there would be no problem
with such
repurposing.
Qualified with a very big if Chris.
Hey it gets done in Europe with much greater regularity
than here, and they have older presses in a lot of cases than we do. And
again, obviously with inkjet printers it can be done very well and the
primary reason why is that the printing process is very predictable. Really
no one in high-end photographic imaging with inkjet printers is
manipulating 6+ channel (in some cases 10+ channel) files before the go to
print. They're working in RGB mostly, with some working with CMYK. In any
event, direct control over the actual print channels isn't available.
Like any rational company, I'm sure Adobe solicited
feedback from
their customers and incorporated it.
My point is that it should have been there since v1.0
Chris. My
company did not move up to AID from QXP until AID CS2
*had* this "safe
CMYK workflow" policy.
Umm yeah. I'm sure a lot of people had a laundry list
of "oh that should have been in 1.0, what were they thinking?"
Let's get real. The fact of the matter is, color management wasn't on by
default until CS2. It would have been a very good thing to have the
Preserve Numbers policy there earlier than CS2. But it became a requirement
as a result of the decision to turn color management on by default.
I submit that there have been no problems becuase by
default these
General Purpose 2 colour settings presets *use safe
CMYK by default* -
so there will be no problems like I am talking of
(unwanted
reseparation of CMYK elements based on their tag).
Yeah, OK.
Are you saying that it would not be considered a
problem if one was
using the "preserve embedded (CMYK) profile"
policy, imported a legacy
Max GCR K only tagged file with K only elements into a
document
profile of SWOP v2 and printed CMYK separations or
composite CMYK?
No.
So Adobe thought it was an improvement to CM, to have
it dumbed down
so that it would not change values. It may not have
happened by
default, but it did happen with the right combination
of settings as I
have listed above (and again below).
It was an improvement to have color management on,
embed the Document CMYK profile, and embed the color management policies,
while not converting CMYK data, by default.
That we even still dealing with CMYK at the front end
at all is a
testimony to how unsophisticated our applications,
workflows, and
process control really are.
Is having precise control unsophisticated?
No.
This is what working in final device space with no
conversions give
those that require it - precise control.
The argument that the only way to get it is via CMYK is
demonstrably false. That you can get precise control on something like most
press conditions today is laughable.
Even in such conditions, it can sometimes help to work
in CMYK (even
if the RIP is CcMmYK). I have had one specific problem
with inkjet
colour builds for dark coloured areas in one job that I
recall and the
only thing that helped was a CMY only separation so
that the RIP would
not lay down any K at all and only use CcMmY for this
area (a persons
face in shadow under a hat brim).
Most fine art photographic printing is done with RIPs
that do not accept CMYK. They receive RGB data only, and perform their own
separation internally.
The example doesn't reveal the device, RIP, paper,
inkset or any of the settings used, or how the file was converted to CMYK
to begin with and what black generation settings were used. So as provided
I don't find it persuasive that working in CMYK to produce a CMY separation
wasn't simply a workaround for a problem introduced in a previous step. And
it's that problem that should be rectified.
If you still hold this position, despite my examples
above, then we
will have to agree to disagree on where the problem
lies Chris.
The example isn't even remotely compelling at this
point.
"Numerically correct" applies only to a
specific printing condition.
That is all that I am talking of Chris.
Give then wide assortment of printing conditions due to
paper, ink, resolution, screening algorithms, it is usually a guess the
size of a barn door as to what that print condition actually is.
Don't you build your skies with a fudge factor with
slightly less magenta in them, just because it's possible magenta may run
heavy on press? And if it does, the sky may go slightly purple? If so, that
compensation is an inaccurate separation. It creates an inaccuracy because
an error in one direction is worse than an error in another. The greater
the error reduction, the more accurate the separation can be, rather than
intentionally inaccurate to add in a fudge factor. There are a number of
examples like this where we go with safe options rather than the accurate
option, because we don't know the exact behavior of the output condition,
or its stability.
Yes, agreed - but this has no bearing on the workflow
of a user for a
single condition that does not understand why their
colour builds are
magically being changed at output to print or PDF,
because their image
has a different profile to the document and they are
printing
seps/comp 4C with a preserve embedded profile policy.
If they don't understand why these things aren't
happening, they don't fully understand their application and the important
of its settings. The defaults are safe. Use them.
When I load in the preset for North America General
Purpose 2 - guess
what is in the CMYK field? It is the safe value locked
preserve
numbers option, not preserve profile (alter colour
values).
You said "if you are referring to a non-safe
CMYK" workflow policy. Such a policy is NOT a default. North America
General Purpose 2 is the default and the CMYK color management policy it
dictates is Preserve Numbers (Ignore Linked Profiles).
There's only one output profile that you can choose
instead of
multiple output profiles to account for different
amounts of black
generation
Not a real concern, in Photoshop the images are put in
their correct
GCR etc. All the files are preped for this one
condition, they can
have any profile and the safe CMYK workflow option will
ensure that
the numbers remain that way, while one can take
advantage of the ICC
profile in Photoshop.
You're talking about two completely different workflows
at the same time. You're talking about the merits of a traditional, early
binding, pre-separated workflow, for a specific printing condition, with no
need or desire to ever repurpose the document.
And yet you complain about the application lacking
granularity for smarter CMYK to CMYK conversions so that color appearance
can be preserved while preserving things like black generation and
preventing 100%K text from turning into 4-colors. So which is it?
A lot of people no longer want to build single
destination files, nor do they want to, nor do they need to. Early binding
workflows are inefficient, and inflexible.
You just have a different problem than the ones you're
alluding to,
a problem for which there is a solution that's been
around for a long
time: get a proof, look at it, color correct the
originals, rinse and
repeat until the proofing budget dries up or you like
the proof. A lot
of people don't like such iterations anymore than
others don't like
black only text in a TIFF turning into four color text.
<
Agreed Chris.
One of those workflows leads to a dead end, often
before there is a real solution. The other, at least, allows for refinement
so that we don't have to mess around with such silliness.
Chris Murphy
Color Remedies (TM)
New York, NY
___________________________________________________________________________
Re: Color Management in Private Book Publishing
Posted by: Dan Margulis
Wed Jun 27, 2007 8:58 am (PST)
Terry Wyse writes,
It's fairly meaningless to talk of "SWOP"
profiles without some sort
of reference to where the measurement data came from.
OTHOH, if one
took the now dated TR001 characterization data and
built a couple of
profiles using different profiling software and/or
gamut mapping
options and then compare these to Photoshop's
"USWebCoated(SWOP)v2",
then you'd have a meaningful comparison. But to compare
profiles
built from different "SWOP" data sets is
meaningless.
On the contrary, how the profile was created is ancient
history. The only thing we care about now is how it behaves in the wicked
world, where few printers who claim to comply with SWOP actually do.
Clients do not care how the profiles was generated and they do not care
what the printer's claims are with respect to standards. They care if the
color does not come out as expected.
All these profiles claim to be for SWOP conditions.
With rare exceptions, it's not feasible for users to investigate whether
the printer's actual process control practices match his claims, if they
even know who the printer is going to be in the first place. The only
question is which one(s) of the many profiles that have SWOP in their names
are likely to produce the most effective result in the real world.
Analog and virtually any (non-color managed) digital
dot-proofing
system "suffers" from having near-perfect
"wet ink trap"
characteristics. In other words, overprinting solids
"trap" with near
perfect efficiency. In the case of C+M overprints,
these would have a
relatively purple bias since the magenta colorant is
going to
overprint cyan perfectly and not show the relative loss
of trapping
efficiency as you'd have on a press with the typical
KCMY (magenta
over cyan) ink sequence. A profile made from such a
proofing system
would compensate for this natural purple bias by
reducing the amount
of magenta ink when overprinting cyan ink during the
CMYK conversion.
When this goes to press however, this C+M combination
would tend to
shift towards cyan due to the less efficient wet ink
trap of the
printing press. By the same token, a profile made from
REAL press
data such as TR001 would see the less efficient
overprint
characteristic of magenta over cyan and compensate by
adding
relatively more magenta in blues. Make sense?
The argument makes sense but there's a counter. The
magenta colorant in analog proofing is more transparent than magenta ink,
particularly later in the run. And since magenta is laid down *after* cyan,
this would have the theoretical effect of making the press colors purpler.
Now these two factors can be meaningless, or they can
cancel each other out, or possibly the effect is cancelled out by other
factors we don't know about.
Realistically, however, there can't be a significant
difference between analog proof and press sheet in these areas. As these
endless threads have made clear, deep blue is an absolutely critical color
in professional work. Clients reject for inaccuracy there more than with
any other color. The rejections almost invariably come when the color is
too purple, rarely when it's too cyan. That's why the experienced users are
not shooting for colorimetric accuracy with their profile, but rather
something that is more likely to get a good result--something that guards
against the appearance of purple.
It would theoretically have been possible, therefore,
for the analog proofs to be *purpler* than the press, but if they were
regularly *less* purple than the pressrun, there would have been
unbelievable howling from the prepress and the printing industry both.
My advice to anybody concerned that this is an issue
but still wants
to produce "SWOP" separations, they should go
to either
www.gracol.org or www.swop.org and download the latest
"G7" family of
profiles. Theirs one flavor of GRACoL for Paper Type 1
(commercial
sheetfed on typical gloss coated paper) and there's two
flavors of
SWOP, one for Paper Type 3 (a neutral white coated
publication paper)
and one for Paper Type 5 (dirty yellow publication
paper, same as
TR001). The SWOP2006_Coated3 profile is essentially the
new default
SWOP profile and should be considered a replacement for
Photoshop's
supplied SWOP profile.
I took a quick look at this profile and I agree that
with respect to blues, cool neutrals, and black generation, it's
considerably better than SWOP v2. I didn't check anything else. However,
being based on machine measurements and an inaccurate colormatching
formula, it *does* have the typical purple shift, though nothing as bad as
SWOP v2. However, it's something to watch, a minor, manageable problem.
It does, however, reemphasize how far off base the SWOP
v2 profile is with respect to blues. The two are farther apart than can be
explained by any normal press conditions--and I think most people would
agree that the Coated3 profile is itself too purple in the blue range,
persons who worship spectrophotemeters excepted.
Dan Margulis
___________________________________________________________________________
Re: Color Management in Private Book Publishing
Posted by: Stephen Marsh
Wed Jun 27, 2007 8:59 am (PST)
André Dumas wrote:
Hello Stephen,
I can't find any message where you said that, so I'm
sorry I must
have you mixed up with somebody else.
But someone did send me a message to that effect and
now I remember
that at the time we were talking about galvanized farm
structures and
concrete wall with a purplish cast and I also remember
that the
addition of yellow improved those and it also had a
positive effect
on people skin tones better than just the removal of
magenta.
André, it may have been me, I was questioning
the addition of yellow to make a 'pure 4c' blue hue (saturated or pastel) -
as yellow is a blue killer...unless some strange inkset or stock, then I
doubt I would have suggested this.
But you go on to mention some other situations that may
not be a blue and they may be more neutral/ish, so of course having more
balanced magenta/yellow with a little higher cyan would help neutralize
things if this was what was wanted (more neutral appearance).
A neutral or a hue lacking saturation or a bright or
pastel blue are different beasts, in this new discussion I was talking
about 'pure' blue - for all I know the colours of your objects are not blue
and or yellow is not such a bad thing in detailed blue areas (just not
where we wish to show saturation or a 'bright' blue colour).
Stephen Marsh.
___________________________________________________________________________
Re: Color Management in Private Book Publishing
Posted by: "Jim Rich"
Wed Jun 27, 2007 3:48 pm (PST)
Hi Dan,
If I am reading this correctly, ah...you appear to be
saying that it is purple blues are the main reason for rejected proofs.
I am having a hard time buying into what you are
saying. But I can be persuaded if you can show me the data for that
statement.
My experience say just over the last two years with
calibrating printing presses and proofers using tools like linearization
methods, colorimetry and icc profiles, is nothing like you are suggesting.
And remember I used the words tools. So I pull out the right tool out of my
tool box at the right time and used it and it worked with out much fuss.
My experience and observation is if there really is a
main reason ( and there might not be) for proofs to press sheets or
vice-versa with color matching and proofs being rejected are issues with
paper color, neutral gray and contrast primarily. And then and after those
issues there might be a problem with color areas being off in some
direction. But blues in particular as the main problem, definitely not.
Here is an example of that is typical of what I see.
Recently I worked with a large publisher who does good quality gravure
printing. We compared some of the gravure printing (that was using a SWOP
like profile as its target) to a Veris, Epson and an HP (z2100) and the
only main problem with proofs that our eyes saw was with the reds on the
Epson. And the Epson and HP was using the new SWOP. I spent about two weeks
looking at this. It was quite eye opening.
In this case, the big problem was getting the paper
colors from the press sheet to the ink jet paper to match. Once we did
that, there were only and I quote, "nit-picky color problems"
such as correcting one percent here and one percent there. And as this
group of color experts pointed out that even if those small corrections
were done you would never realize them in a press run due to normal
variation.
I could go no an discuss other printing processes and
sites that I have had my hands on lately such as igens and offset presses
where we also used ink jet printer for the prepress. As well as the SWOP v2
and SWOP 2006 in multiple comparisions. In those situations no one was
talking about or seeing a problem with blues. An in a lot of cases this was
done by committees of designers, and photographers, as well as press
operators and managers. If there were any comments about a color match, it
was always in this type of order: Paper color, the neutrals and reds.
And in all of those cases I doubt that any of this was
luck. I just followed the basic rules for setting up the press and prepress
rips, using colorimetry to compare measurements like Chroma etc and
creating icc profiles.
At times it was almost boring because I did not have
apply much if any color skill. And there was definitely no profile editing
required to get good reasonable color matches.
Mileage will vary.
Jim Rich
___________________________________________________________________________
Re: Color Management in Private Book Publishing
Posted by: "Andrew Rodney"
Wed Jun 27, 2007 3:51 pm (PST)
On 6/27/07 9:13 AM, "DMargulis" wrote:
On the contrary, how the profile was created is ancient
history. The only
thing we care about now is how it behaves in the wicked
world, where few
printers who claim to comply with SWOP actually do.
Clients do not care how
the profiles was generated and they do not care what
the printer's claims are
with respect to standards. They care if the color does
not come out as
expected.
You all recall the dirty joke about the three biggest
lies in the world? Well one should be "We print SWOP".
If someone tells you they conform to a process and
don't, they are simply telling you a big fat lie! They should either
provide a profile or conversion method for said process or conform to the
process they say they are. You simply can not blame a profile or any
conversion method for poor conversions when the guy printing the job tells
you utter falsehoods. What would happen if you purchased an Epson printer,
downloaded a profile for that device and paper only to find out it was
built for a Canon printer and different paper? Oh, its the profile's fault.
Sorry, that's just silly talk.
The argument makes sense but there's a counter. The
magenta colorant in
analog proofing is more transparent than magenta ink,
particularly later in the
run. And since magenta is laid down *after* cyan, this
would have the
theoretical effect of making the press colors purpler.
Immaterial. A proof is supposed to match another
process. An Epson printer is totally different than a press yet lots of
shops and end users (myself included and those I've worked with) can match
an Epson to a press sheet.
Again, the person making a proof can tell you it will
match and lie. That's the fault of the person, not the technology.
Realistically, however, there can't be a significant
difference between
analog proof and press sheet in these areas. As these
endless threads have
made clear, deep blue is an absolutely critical color
in professional work.
Clients reject for inaccuracy there more than with any
other color. The
rejections almost invariably come when the color is too
purple, rarely when
it's too cyan. That's why the experienced users are not
shooting for
colorimetric accuracy with their profile, but rather
something that is more
likely to get a good result--something that guards
against the appearance of
purple.
This stuff is supposed to match, it can and does all
the time WHEN the process is defined and handled correctly.
You seem to enjoy finding situations where the process
falls apart often due to poor process control, user error or total
misunderstanding on the part of two parties and then placing the blame on
the technology, not on the people incorrectly using the tools as designed.
These users and your readers would gain far more from having their problems
addressed rather than simply issuing blanket blame on technology.
If you put a car parked in a garage in Drive and slam
on the gas, who's to blame for the remodel of said garage? Its hardly
appropriate to blame the manufacturer of the car UNLESS Reverse really
makes the car move in a forward direction. I would submit that this
doesn©ˆt happen very often or the driving public would abandon
this mode of transportation pretty quickly.
It would theoretically have been possible, therefore,
for the analog proofs
to be *purpler* than the press, but if they were
regularly *less* purple than
the pressrun, there would have been unbelievable
howling from the prepress and
the printing industry both.
Oh god, theoretically. Good way to build wiggle room.
Theoretically it could be green! Yet the idea is the proof is supposed to
match the press sheet and the vast majority of people doing this indeed
make an acceptable match or we'd have seen proofing systems being rejected
from day one. Are you suggesting that the myriad of proofing systems always
or even most often fail to match the final process? I haven't heard the
©¯print industry©˜ reject these tools, in fact, just
the opposite.
I took a quick look at this profile and I agree that
with respect to blues,
cool neutrals, and black generation, it's considerably
better than SWOP v2.
Its NOT better, its different! I don't know why you
refuse to look at the fact that the TR001 profile produces excellent
results on a device that conforms to TR001. A G7 profile is no better or
worse here either. Send a document separated to G7 spec's to a device that
conforms to TR001 and you'll get different results. That doesn©ˆt
make the G7 profile bad. The user who separates to the wrong process is at
fault.
It does, however, reemphasize how far off base the SWOP
v2 profile is with
respect to blues. The two are farther apart than can be
explained by any
normal press conditions--and I think most people would
agree that the Coated3
profile is itself too purple in the blue range, persons
who worship
spectrophotemeters excepted.
Yes, they are different. There's a shock! And just what
"Normal" press condition are you referring to? How is this
defined? And no, most people would not agree without doing some tests to a
device that actually conforms to the behavior specified and send the data
to said devices using the conversion method that is characterized and
defined by the correct profile. This is all a bit silly since you're only
viewing numbers and you are biased into thinking that one set is correct
and the other isn't when in fact, you haven't at all looked at the device
behavior let alone measured it. Its like suggesting the G7 profile should
work equally for SWOP and Sheetfed devices. Or that the Canon profile
should work equally for the Epson printer.
So lets run some tests out to both G7 and TR001
conforming proofing devices (a press if someone is willing). I can get the
proofs made. What do you say Dan, let©ˆs put our money where are
mouth©ˆs are. I have a superb shop that would run the proofs for
us. Want to get it done by Photoshop World?
Andrew Rodney
___________________________________________________________________________
Re: Color Management in Private Book Publishing
Posted by: "Jim Rich"
Wed Jun 27, 2007 7:02 pm (PST)
Andrew,
A small point.
To be technically correct here when it comes to these
profiles, there is a Gracol 7 and a SWOP 2007 profile.
The G7 process is a press and proofer calibration
method.
And in terms of looking at printed results, generally,
when you use the Gracol 7 profile as the target you get better shadow
details if you compare the printed results to the either SWOP v2 or SWOP
2006.
Jim Rich
___________________________________________________________________________
Re: Color Management in Private Book Publishing
Posted by: Dan Margulis
Thu Jun 28, 2007 7:53 am (PST)
André writes,
I hear you Dan, but it was solely the domain of highly
skilled
individuals and not available to people like me. The
ICC is a
perfection of what you mention thought out in terms of
an evolution
toward new *standards* of production.
These new techniques and tools allow me to express my
creativity in
ways that would have been impossible without them, they
are
liberating. Like the computer and powertools etc.
I write merely to stress our agreement on the above. It
is exactly what I wrote in 1999, which I previously posted. Inasmuch as the
entire thread began with the implication that what I wrote back then has
been disproven by subsequent events, I will repeat the paragraph:
"Professional photographers, being relatively
quality-conscious, willing to invest time in learning, and inexperienced in
the vagaries of the CMYK colorspace, are the prime beneficiaries. Although
Photoshop's calibration features are free and an ICC profile editor tends
to cost $1,000 or more, it may be so much easier for a photographer to
learn and implement that it will justify the expense."
Dan Margulis
___________________________________________________________________________
Re: Color Management in Private Book Publishing
Posted by: Dan Margulis
Thu Jun 28, 2007 12:18 pm (PST)
Jim Rich writes,
If I am reading this correctly, ah...you appear to be
saying that it is
purple blues are the main reason for rejected proofs.
I did not say that. The large majority of images don't
contain deep blues, so it couldn't possibly be the main reason for rejected
proofs no matter how bad the problem is. What I said was, "deep blue
is an absolutely critical color in professional work. Clients reject for
inaccuracy there more than with any other color." By that I did not
mean that a larger *number* of proofs are rejected for bad blues than for
bad reds, say, because deep red is a very common color and deep blue not
particularly. I meant that if you have one image that features deep reds
and another that features deep blues, the odds of the blue one getting
rejected are much higher than of the red one.
My experience and observation is if there really is a
main reason ( and
there might not be) for proofs to press sheets or
vice-versa with color
matching and proofs being rejected are issues with
paper color, neutral gray
and contrast primarily. And then and after those issues
there might be a
problem with color areas being off in some direction.
But blues in
particular as the main problem, definitely not.
If I had to state the reasons that proofs are rejected
in order of frequency, this would be my list:
1) Colors appear muddy.
2) Image is too flat.
3) Overall weight of image is not what was expected.
4) Lack of detail in saturated colors.
I could go no an discuss other printing processes and
sites that I have
had my hands on lately such as igens and offset presses
where we also used
ink jet printer for the prepress. As well as the SWOP
v2 and SWOP 2006 in
multiple comparisions. In those situations no one was
talking about or
seeing a problem with blues. An in a lot of cases this
was done by
committees of designers, and photographers, as well as
press operators and
managers. If there were any comments about a color
match, it was always in
this type of order: Paper color, the neutrals and reds.
I don't think reds are comparable to blues. For sure
there are a lot more pictures that feature reds than feature blues, so it
seems like the problems are worse. But I find that a client would be as apt
to reject for a red being too fiery as for too rosy. That's in contrast to
blues, where the cause for rejection is almost invariably that the color
has gone purple. With reds, there's little reason to bias the profile one
way or another. With blue, the profile should definitely favor cyan
generation at the expense of magenta.
As for them not seeing a problem with blues, I have to
think that they could not have looked for them. The difference between SWOP
v2's handling of blues and those of other profiles is gross. I think
clients can see a shift toward purple if the cyan goes down and/or the
magenta goes up even as little as a combination of 2-3%. The variation
between SWOP v2's treatment and those of other profiles is four times that
or more in deep blues. For example, I showed an example in PP5E where one
profile generates 91c61m0y and SWOP v2 renders the same color as 87c67m0y.
That's an enormous difference; if one assumes that the first is the desired
blue it would not even be technically possible to match it by manipulation
of inks on press because the whole image would go green before we were even
close.
I've showed the swatches in PP5E to color-blind people
and asked for assessments on blueness, and they were spot on, and
complained about the SWOP v2 versions as being disagreeably non-blue
(though they weren't quite sure what the problem was). If color-blind
people can see the shift easily, and if the numbers change that radically,
then I can accept that your people didn't look for a problem, but I can't
accept that they couldn't see it if they did look for it.
Dan Margulis
___________________________________________________________________________
Re: [color theory] Re: Color Management in Private Book
Publishing
Posted by: "Jim Rich"
Thu Jun 28, 2007 1:35 pm (PST)
Hey Dan,
Thanks for restating that. Now I have a better sense of
you post.
It sounds like we are in agreement on a number of
issues (but not all) you are seeing.
However, in the situation I described, my publisher
friends or I did not see what you are experiencing.
As I remember, the solids and overprint colors on the
proofs we were inspecting (expect for the solid magentas) did have solid
primaries and overprints that were within the 5 delta of 12647-2 LAB values
for Gracol 2007 specs. And the same tolerances for the ISO SWOP LAB values
of solids except for the Magenta of the Epson Proof. And solid magenta LAB
numbers were within in 7 delta e of the ISO targets for solids and
overprints on the Epson. It is a hue problem. That included the blues being
with the ISO tolerance. I found that surprising, but that's what it
measured in LAB. An now that I think about, I don't think anyone asked to
measure density.
And the HP z2100 solids and overprint colors were spot
on the ISO 12647-2 spec. using the Gracol 2007 and SWOP 2006 profile as the
target.
We used the ISO suite of CMYK images. One that comes to
mind is the three kodak ladies and one is wearing blue Kimono.
I know I am not mentioning SWOPv2 at the gravure based
publisher, but at another publisher here in town with the igen we did also
did not see any blue problems. And these guy print blue book covers that
are process and pantone all of the time on the igen as well as printing on
a few older Epsons using the same profiles. But in that situation I
experienced, the igen not that easy to control. Definately not an offset
press, but by using profiles we got both igens to have close visual match
without too much fiddling around. Meaning we did have to apply something
like a -1% magenta and -2% black midtone move after the profiles were
created to one press. Not a big change but just enough to make the igens
have a better shared appearance.
I hope this makes some sense.
Jim Rich
___________________________________________________________________________
Re: Color Management in Private Book Publishing
Posted by: "Andrew Rodney"
Thu Jun 28, 2007 4:49 pm (PST)
On 6/28/07 2:12 PM, "Jim Rich" wrote:
I know I am not mentioning SWOPv2 at the gravure based
publisher, but at
another publisher here in town with the igen we did
also did not see any
blue problems.
How can that be? The numbers imply that it will always
shift blue! Of course I too have seen the same results from this profile.
I asked if the U.S. Web Coated (SWOP) v2 profile always
produces blues to the Colorsync list assuming that there are at least a few
people who have also tried it. Got this in less than 24 hours:
I can provide some indirect evidence that the above
profile is probably doing the right thing in this
region
of colorspace.
The actual problem is Blues-going-Purple: colors that
should be
blue have too much magenta and hence appear purple.
This comes
about by doing a certain kind of gamut mapping in
CIELAB
colorspace where you map along constant radial lines of
Hue.
While CIELAB does a reasonable job of being
perceptually linear
in many parts of the space, it falls flat on its face
in the Blues.
CIELAB also suffers in the reds which go slightly
orange, but not
to the degree that blues go purple. Doing this Hue
preserving gamut
mapping in CIECAM02 eliminates these problems.
As a profile builder, I've spent considerable effort
analyzing
US Sheetfed Coated (V2), a high quality profile if
there ever was
one. Insights that I've gained on this Profile probably
apply to
the Web Coated profile as well I should think.
(Although Knoll
may not have built this profile - not sure). I've
looked at the
gamut mapping vectors in this region and seen that they
are not
Hue preserving and in fact smoothly bend toward Cyan
which cures
the Blues-going-Purple problem. I've looked at the
global
separations of both profiles and they are of a similar
quality.
I would thus surmise that the same gamut mapping
strategy was
used in the Web Profile as was effectively employed in
US Sheefed
which cured the problem.
Harold
TOSHIBA AMERICA BUSINESS SOLUTIONS 2 Musick,
Irvine, CA 92618
Hi Andrew,
In regards to blue rendering, I see differences between
SWOPv2 and
SWOP06 and I prefer SWOPv2 on a purely subjective
level. I tend to
see SWOP2006 going more red/purple than SWOPv2 (though
the expert
says 'less') and I'm not sure if we could even place a
binary 'right/
wrong' on this kind of shift. I'd say this is not an
unusual or
unexpected color shift for a SWOP press because SWOP
presses do not
hold color-metric standards.
As far as a TR001 proofing device is concerned I'm
afraid this animal
never existed and probably never will. Even the more
modest SWOP
Proofing Certification is hardly a gauge of the
behavior of a press.
In fact, blue-to-purple shifts are a notorious problem
with SWOPv2
separations sent to PolaProofs, Analog Matchprints
& XP Approvals and
I could only see SWOP06 exaggerating this known issue.
However, we should not consider this a fault of SWOPv2
or even
SWOP06, but rather a flaw (perhaps unavoidable) in the
implementation
of expensive proofing devices.
Perhaps you can convince some SWOP press to piggy back
a few
swatches? I'd love to see the results myself.
--
Kevin Muldoon, Owner
TrueBlueDot - Fine Art Printing
New Haven, CT 06511
www.truebluedot.com
Of course, other than you, I, Chris, Kevin and Harold
of Toshiba, everyone agrees that the U.S. Web Coated (SWOP) v2 profile
shifts blues!
I await other replies from the list from others who
disagree with everyone after actually using this profile for output.
___________________________________________________________________________
Color Management in Private Book Publishing
Posted by: "Paul Foerts"
Thu Jun 28, 2007 4:49 pm (PST)
Jim Rich wrote:
My experience say just over the last two years with
calibrating printing
presses and proofers using tools like linearization
methods, colorimetry and
icc profiles, is nothing like you are suggesting. And
remember I used the
words tools. So I pull out the right tool out of my
tool box at the right
time and used it and it worked with out much fuss.
What tools were used to check the mechanical precision
of the multicolor offset presses?
What tools were used for press "calibrating"?
How many "CMY gray" patches were measured to
cover the whole printed sheet?
Were these printing presses able to print the same
"CMY" gray within a delta E less than 32? How many sheets were
printed?
Did you use a GATF or other reference test form +
printed "reference sheet" to find the printing parameters needed
for the emulation of a standardized printing condition?
My experience and observation is if there really is a
main reason ( and
there might not be) for proofs to press sheets or
vice-versa with color
matching and proofs being rejected are issues with
paper color, neutral gray
and contrast primarily. And then and after those issues
there might be a
problem with color areas being off in some direction.
But blues in
particular as the main problem, definitely not.
You are right about non-matching proofing paper color.
But the main reasons for discussion in this area are optical brighteners
and metameric effects. Were the lightbooths calibrated to NIST-traceable
standards (using a spectroradiometer and calibration software)?
I could go no an discuss other printing processes and
sites that I have
had my hands on lately such as igens and offset presses
where we also used
ink jet printer for the prepress. As well as the SWOP
v2 and SWOP 2006 in
multiple comparisions. In those situations no one was
talking about or
seeing a problem with blues. An in a lot of cases this
was done by
committees of designers, and photographers, as well as
press operators and
managers. If there were any comments about a color
match, it was always in
this type of order: Paper color, the neutrals and reds.
Whatever... I've seen a lot of non-blue skys in books
and magazines. Some like it blue, others don't mind the skys.
Some like point and click, others use expensive
equipment and invest a lot of time doing the numbers themselves. I've seen
outstanding "point and click" pictures but i've never met a
"point -and-click-photographer" saying that it is impossible to
take good pictures using the manual setting.
And in all of those cases I doubt that any of this was
luck. I just followed
the basic rules for setting up the press and prepress
rips, using
colorimetry to compare measurements like Chroma etc and
creating icc
profiles.
Why create "press" profiles"? In other
words: "printed-sheet-profiles"? You were not aiming a standard
printing condition? (= existing/free stuff) How many more profiles to go?
At times it was almost boring because I did not have
apply much if any color
skill. And there was definitely no profile editing
required to get good
reasonable color matches.
As an offset press is a profile editor... which makes
it possible for a printer to match a proof more (using a standardized
workflow) or less (when a non cooperative workflow has been used),
"profile editing" is a "standard" procedure. I remember
the times when it was called ink key setting...
Mileage will vary.
Yep
Paul Foerts
___________________________________________________________________________
Re: Color Management in Private Book Publishing
Posted by: "Henry"
Thu Jun 28, 2007 4:49 pm (PST)
As I remember, the solids and overprint colors on the
proofs we were inspecting (expect for the solid magentas) did have solid
primaries and overprints that were within the 5 delta of 12647-2 LAB values
for Gracol 2007 specs. And the same tolerances for the ISO SWOP LAB values
of solids except for the Magenta of the Epson Proof. And solid magenta LAB
numbers were within in 7 delta e of the ISO targets for solids and
overprints on the Epson. It is a hue problem. That included the blues being
with the ISO tolerance. I found that surprising, but that's what it
measured in LAB. An now that I think about, I don't think anyone asked to
measure density.
Is it that there is a larger hue error with solid
Magenta on the Epson proof, greater than the hue error found with Cyan and
Yellow--that the profile conversion is not matching the target solid
Magenta as well as you expected? Or is it that a solid Magenta mismatch
isn't surprising but a solid Blue match is?
Henry Davis
___________________________________________________________________________
Re: [color theory] Re: Color Management in Private Book
Publishing
Posted by: Dan Margulis
Fri Jun 29, 2007 8:03 am (PST)
Jim Rich writes,
We used the ISO suite of CMYK images. One that comes to
mind is the three
kodak ladies and one is wearing blue Kimono.
That's an excellent image for a lot of purposes but not
necessarily for seeing the kind of problem that I'm describing in deep
blues. That kimono isn't especially saturated, so the effect gets masked
somewhat by the contaminating colors.
My copy of that image is drum scanned. I assigned SWOP
2006 to it, and then converted a copy to SWOP v2. In the original
(SWOP2006) an area in the woman's near shoulder measures 98c66m20y12k. In
the version converted to SWOP v2, it goes to 96c70m22y6k. That's
significantly purpler, because the cyan has gone down and the magenta
up--and I think that the SWOP 2006 has it too purple already.
Accepting for the sake of argument that SWOP2006
reports the LAB values accurately (and I don't accept that it does), then
the original reads 32L(1)a(37)b--just to the cyan side of blue. The SWOP v2
version reads 32L2a(37)b--identical LB values, but the A 3 points higher,
changing the color to be to the purple side of blue.
Now I would agree that in the context of this
particular image, granted how much yellow and black is in there, few people
would get upset at the difference between the two. However, it can't be
denied that the SWOP v2 version is significantly purpler.
Where the problem really manifests itself is in deeper,
richer blues. I show one example each in the LAB book and in PP5E. The
first one shows a deep blue jacket from a clothing catalog that was in fact
rejected in print by the client due to going purple. The second shows
Crater Lake, described as being one of the bluest objects in nature. I show
how several different profiles separate the same original file, and the
SWOP v2 version was obviously the purplest, so much so that IMHO it would
have been rejected by the client had it appeared in advertising.
Of course, one can get around the problem in various
ways in Photoshop, such as by using Selective Color after the
separation--but it requires us to be aware that there *is* a problem.
Dan Margulis
___________________________________________________________________________
Re: Color Management in Private Book Publishing
Posted by: Chris Murphy
Fri Jun 29, 2007 8:04 am (PST)
On Jun 28, 2007, at 12:15 PM, DMargulis wrote:
For example, I showed an example in PP5E where one
profile generates 91c61m0y and SWOP v2 renders the same color as 87c67m0y.
That's an enormous difference; if one
assumes that the first is the desired blue it would not
even be technically possible
to match it by manipulation of inks on press because
the whole image would go
green before we were even close.
Right. Which is why the claim that this profile is so
wrong for the conditions it's targeting makes exactly zero sense. There are
hundreds of thousands of installations of Adobe applications of various
versions that are using this profile as the default for conversion. The
purported massive deficiency of this profile that would cause problems such
that they could not be fixed on press would have caused an absolutely
conniption well beyond that seen with the purported embedded profile market
failure.
I've spoken to dozens of printers who recommend the use
of this profile, and none have complained about these large blue to purple
shifts that you allude to. I simply don't find it persuasive. Printers,
pre-press and their customers would have had so many cows by now that we'd
be getting paid to eat all the glut of beef on the market.
The extremity of your complaint, the grandiose nature
of this supposed shift makes it impossible to believe that this problem is
so confined that the negative behavior has only resulted in the sound of
crickets chirping, if it were true. And now many, many years after TR 001
was released, we have an updated SWOP 2006 #5 sheet profile that
overwhelmingly agrees with the separations of U.S. Web Coated (SWOP) v2.
My hypothesis is that you're either magenta adverse or
you're printing to conditions for which these profiles were not intended or
in improper viewing conditions. In all printed materials I've seen of
yours, I think blue sky and water are decidedly too cyan.
I've showed the swatches in PP5E to color-blind people
and asked for
assessments on blueness, and they were spot on, and
complained
about the SWOP v2 versions as being disagreeably
non-blue (though they weren't quite
sure what the problem was). If color-blind people can
see the shift easily, and
if the numbers change that radically, then I can accept
that your people didn't
look for a problem, but I can't accept that they
couldn't see it if they did
look for it.
I've been looking for quite a while now and haven't
seen this problem for print conditions that this profile was intended for.
I have normal vision. Your explanation?
Chris Murphy
Color Remedies (TM)
New York, NY
___________________________________________________________________________
Re: Color Management in Private Book Publishing
Posted by: Chris Murphy
Fri Jun 29, 2007 8:07 am (PST)
Dan Margulis wrote:
I took a quick look at this profile and I agree that
with respect to blues,
cool neutrals, and black generation, it's considerably
better than SWOP v2.
Take two blues and cool neutral: 7L*,4a*,-54b*;
60L*,1a*,-54b*; 50L*, 0a*,-2b*
The first is a deep blue on a banner hanging on a
building, the second is a blue sky, the third is a cool gray from a Pantone
swatch book.
First color:
SWOP v2 produces
100c,82m,29y,44k
SWOP 2006 Coated3 produces:
100c,67m,6y,66k
Delta E 2000 3.5
Delta H 2.03
Second color:
SWOP v2 produces
64c,38m
SWOP 2006 Coated3 produces:
65c,39m,1y,1k
Delta E 2000 5.36
Delta L 6
Delta H 2.55
Third color:
SWOP v2 produces
56c,46m,44y,10k
SWOP 2006 Coated3 produces:
54c,45m,42y,17k
Delta E 2000 8.12
Delta L 8
Delta H 0.94
Delta E is based on Delta E 2000, and computed by
assigning the opposite profile to each conversion, and then converting back
to LAB yields two sets of LAB data for comparison of the resulting
conversions. Delta L is the difference in lightness, Delta H in hue.
The data does not at all support the contention that
SWOP 2006 Coated 3 is better than U.S. Web Coated SWOP v2 with respect to
any blue/ purple shifting or neutrality. The primary difference between
them is the paper white. The Delta E 2000 between just paper white between
#3 stock and #5 stock is 4.43. Yet the difference in these colors are less
than that. The colors these CMYKs produce on the OTHER printing process
isn't that different. The difference would obviously be even less if those
CMYK values were printed on the conditions for which they were intended.
However, being based on machine measurements and an
inaccurate colormatching formula, it *does* have the
typical purple
shift, though nothing as bad as SWOP v2. However, it's
something to watch,
a minor, manageable problem.
U.S. Web Coated (SWOP) v2 is based on a #5 groundwood.
It's a completely different stock than #3 sheet, which is the profile
you're comparing those separations to, SWOP 2006 Coated 3. "Nothing as
bad as SWOP v2" does not compute.
It does, however, reemphasize how far off base the SWOP
v2 profile
is with respect to blues. The two are farther apart
than can be explained
by any normal press conditions--and I think most people
would agree
that the Coated3 profile is itself too purple in the
blue range,
persons who worship spectrophotemeters excepted.
Comparing it to the very different data set of
SWOP_2006_Coated3v2 is not at all an apples to apples comparison in
printing processes. But even if we pretend they are, as I've done above,
the difference isn't that great overall, and even less in terms of hue. The
big difference is due to lightness, and then to chroma which is entirely
expected considering the very different stocks being used between the two.
Chris Murphy
Color Remedies (TM)
New York, NY
___________________________________________________________________________
Re: Color Management in Private Book Publishing
Posted by: "Jim Rich"
Fri Jun 29, 2007 10:56 am (PST)
Paul,
I am not sure of the intent of your post. If it is to
question my comments, my experience and observations with this issue, or if
I am really telling the truth or is it something something else???
But since there seems to be some issues on your part,
let me try to be clear. I was only trying to point out my observations and
was not looking for a fight on this issue that Dan brought up.
I was making an argument based on real world
observations and what clients stated during a work cycle. If your
experience or observations are different then share them. The way I read
the posts from Dan is that they prompted a few peoples replys and since
then in subsequent posts he has addressed his original comments so MOST of
us now have a better understanding of what he stated.
It is also very clear that this post is way out side of
the scope of this list and that the common thread is Photoshop SWOPv2
profiles.
However,
I guess you mean things like bearer pressure, plate and
blanket packing? I work with the press crews to check this stuff and then
we talk about it to be sure its in order.
What tools were used for press "calibrating"?
I use a variety of tools. My core set of tools include
a SpectroEye, a DTP70, IC Plate II, an eyeone and sometimes a Pulse, a
custom spread sheet to verify TVI, the Curve tool, Colorthink and
ColorshopX, GMB PMP and Profiler. And of course I integrate the clients
tools such as densitometers into the mix for process control.
What tools do you use?
I use a number of CMY gray patches in various areas of
a press sheet. I use a 50%Cyan, 40% magenta and yellow patch about 1/2 inch
across the leading edge of the sheet right below the color bars. And then
the same CMY gray patches vertically in the center of the sheet.
Typically when I get involved with a press calibration
I try to do the print run with the calibration targets etc on approx. 1000
sheets. Of course the press has to be settled in when that process starts
and SIDs and midtones and gray bars are monitored during the run to be sure
they are within tolerance. Then from the 1000 sheets I pull about 10 sheets
and use them. Take and average the measurements. This usually gives a good
snapshot of a press run that is in within a reasonable tolerance.
I these days I use ISO CMYK images usually in my own
test form, but I am converting to the Gracol test form. No I don't use a
bought reference sheet. There is a lot of evidence that is not a practical
way to go.
These days by using colorimetry for the initial setup
and going by say the ISO 12647 specs and the G7 guidelines seems the way to
get to the ISO specs, at least for me and for a bunch of G7 experts, ink
and paper vendors and printing companies. Other folks still use density and
dot gain to get the press calibration done and it seems to work. And I just
did a gig at a newspaper recently, where it worked out to use the TVI
method. So when in Rome...
I am not sure what your underlying comments is about a
delta E less than 32 and cmy gray? In a Gracol setup I target the cmy gray
patches with appropriate density which I think without looking it up is .54
and or the appropriate L ab values of 54, a 0, b-2. This value is without
paper. I look for a tolerance of 2 delta e, but that depends on the
printers skill and quality levels etc.
As most of us understand, there is more than one way to
get a press and proofer calibrated. There are at least four press
calibration methods I am aware of such as the TVI and density approach, the
more modern G7 method, dumb luck and by the SOTP (seat of the pants). My
belief is that the first two are the more logical approaches especially if
you combine them with process control.
Another of my observations is that if person uses both
colorimetry and skill they stand a better chance to get the job done in the
most efficient manor.
And my opinion is that it is far easier to use color
science that is integrated into color technology tools such as colorimetry
and densitometry for example to get a printing process calibrated and then
if it makes sense create icc press profiles. Doing all of that can be hard
work. Then if there are technical problems you have to consider rolling
your sleeves up and apply skill. And even with using today's color
management tools you still need skill.
You are right about non-matching proofing paper color.
But the main reasons
for discussion in this area are optical brighteners and
metameric effects.
Were the lightbooths calibrated to NIST-traceable
standards
(using a spectroradiometer and calibration software)?
We did use the clients light booths and the RHEM Light
Indicators.
Why create "press" profiles"? In other
words: "printed-sheet-profiles"?
You were not aiming a standard printing condition? (=
existing/free stuff)
How many more profiles to go?
Huh?
I thought I stated I was aiming at Gracol7 and SWOP.
Isnt that what this thread is about?
As an offset press is a profile editor... which makes
it possible for a
printer to match a proof more (using a standardized
workflow) or less (when
a non cooperative workflow has been used),
"profile editing" is a "standard"
procedure. I remember the times when it was called ink
key setting...
Sure an offset press can be a color correction tool,
but it is a very coarse one and there is too much evidence that it is best
to do color editing early in the process say in Photoshop with
soft-proofing and hard copy proofs and not on press, unless you have to.
And even with accurate proofs, common sense says a skilled operator still
makes good color happen on a press.
However, while an offset press can be a profile editor,
but not easily for example in digital printing.
Jim Rich
___________________________________________________________________________
Re: Color Management in Private Book Publishing
Posted by: "Ron Kelly"
Fri Jun 29, 2007 8:55 pm (PST)
Chris:
You and other calibrationists like Andrew Rodney say to
this problem: this is a bad profile.
Among other things, you advise them to get a better
one. Everyone should get a better profile, right? There's printers out
there who do things properly, and don't support companies that don't, etc.
There are several issues with this advice: -this
profile was designed and implemented by "experts" -it is widely
dispersed and a de facto standard -it may well be some time before it is
replaced
You would have us get another profile or profiles,
constructed by the same or perhaps other "experts" in which of
course we should place our complete trust.
With time this profile will be replaced across the
broad spectrum of printing. Hopefully the next standard will be better but
it wouldn't suprise me if it wasn't.
I'll be sending my CMYK files in untagged and doing my
own adjustments for press profile problems for now, and maybe a lot longer.
Ron Kelly
___________________________________________________________________________
Re: Color Management in Private Book Publishing
Posted by: Ric Cohn
Fri Jun 29, 2007 8:56 pm (PST)
On Jun 29, 2007, at 2:18 AM, Chris Murphy wrote:
First color:
SWOP v2 produces
100c,82m,29y,44k
SWOP 2006 Coated3 produces:
100c,67m,6y,66k
Delta E 2000 3.5
Delta H 2.03
I must not be understanding something (and I would like
to). The kinds of numbers you report are similar to my own results.
However, for this deep blue you say the ink build isn't significantly
different? Just from the ink numbers I would have
assumed they are.
U.S. Web Coated (SWOP) v2 is based on a #5 groundwood.
It's a
completely different stock than #3 sheet, which is the
profile you're
comparing those separations to, SWOP 2006 Coated 3.
"Nothing as bad
as SWOP v2" does not compute.
Interesting. It shows my need for more education, but I
don't remember that US Web Coated V2 is based on #5 paper or warnings about
using it for better paper. To tell the truth I'm not sure what #3 or #5
look like. Can you give me an idea of what magazines use what? Is
Architectural digest a #3, or better? Is Parade a #5 or worse? Isn't a #5
stock significantly worse than most printing these days (at least where
color is important)? To me, that alone shows why inadequate having only one
profile to choose from is so problematical.
I may be mistaken, but didn't Pantone change their
formulary in recent years because their research showed that most printing
was being done on whiter papers than when the formulary was originally
developed?
Ric Cohn
___________________________________________________________________________
Color Management in Private Book Publishing
Posted by: "Paul Foerts"
Sat Jun 30, 2007 8:05 am (PST)
Jim Rich wrote:
I'm not sure of the intent of your post.
My intent is to try to people to convince that there is
no way to "profile" an offset press.
I advocate using generally accepted printed reference
sheets, printed on popular papers for which ICC profiles are freely
available.
Printers may test if their presses can meet these
"standards". By using process control tools, the printer can
detect/repair mechanical press defects, adjust prepress and press settings,
chose appropriate inks/papers to come as close as possible to the aim
sheet. From these press-sheets, the printer can read the process parameters
with his equipment for this standard printing condition.
As "proofing equipment" is optimized for
these standard printing conditions, No further "profiling" is
needed. Using a calibrated proofing system as a guide for finding a
standard printing condition may be the most practical approach for most
printers. If the proof can be matched by the printer's presses...
In this case a printer may claim that he meets the
requirements for a standard printing condition.
In all other instances parties should meet before
prepress activities start.
If all "consultants" would agree on these
basic principles, a lot of discussions could be avoided.
My 2 cents
Paul Foerts
___________________________________________________________________________
Re: Color Management in Private Book Publishing
Posted by: Dan Margulis
Sat Jun 30, 2007 8:06 am (PST)
Chris Murphy writes,
First color:
SWOP v2 produces
100c,82m,29y,44k
SWOP 2006 Coated3 produces:
100c,67m,6y,66k
Excellent example. The weak inks, yellow and black,
have little influence on the color. The blueness vs. purpleness depends
almost exclusively on the ratio of cyan to magenta ink. In these two, the
cyan values are the same but in one case the magenta value is 15 points
higher than the other.
Delta E 2000 3.5
Delta H 2.03
Temperature in Moose Jaw, Saskatchewan: 21 degrees
Celsius.
Exchange rate: 34.34 Indian rupees per Australian
dollar.
The data does not at all support the contention that
SWOP 2006 Coated
3 is better than U.S. Web Coated SWOP v2 with respect
to any blue/
purple shifting or neutrality.
Denying that adding 15 points of magenta ink to a blue
shifts the color toward purple is reminiscent of your defense of the
impossibly high dot gain specified in the Photoshop U.S. Sheetfed profile,
see
http:
//www.ledet.com/margulis/ACT_postings/SeparationIssues/ACT-Web-vs-Sheetfed.htm
Pointing out that it is not feasible for the main
Photoshop sheetfed profile to assume even the *same* dot gain as the web
profile, let alone something much higher, I said: "This whole
conversation is as simple as it is ludicrous. Any digital file is going to
appear darker if printed on a web press than on a sheetfed press under
almost any conceivable condition. Logically, therefore, one must expect a
web profile to generate a significantly *lighter* sep than a sheetfed
profile...Instead we get a profile that generates a significantly *darker*
sep.
"We do not need a discussion of tristimulus
values, rendering intents, L*a*b*, colorimetry, ICC politics, how nespaper
printing actually has less dot gain than sheetfed printing, or the square
root of pi here. What we need is for the web sep to be lighter than the
sheetfed sep."
We now have, in the form of the new GRACOL profile,
something that is intended to be used for the same condition as US Sheetfed
v2 is--except that, correctly, the assumed dot gain is around a third
lower. This means that there's roughly the same ratio between these two
allegedly similar profiles as there is between a properly prepared profile
for magazine work and another for newspapers.
I assume that your argument remains the same: 15 points
of extra magenta in a blue is no big deal, overestimating the dot gain by a
third is no big deal.
The extremity of your complaint, the grandiose nature
of this
supposed shift makes it impossible to believe that this
problem is so
confined
The complaint is neither extreme nor grandiose. I have
shown that SWOP v2 generates nice reds and most greens. I have indicated
that deep blue is not a particularly common color in pictures but that it
does occur, and when it does, SWOP v2 may put in, as you have demonstrated,
15 points or so more magenta ink. I have illustrated what this means by
side-by-side examples of both swatches and real images, and I have
explained why the problem is prevalent in machine-generated profiles and
not in human-generated ones. I have pointed out that there are workarounds
after the file enters CMYK, but that if one is not aware that the problem
exists there is apt to be a nasty surprise when ink hits paper.
And now many, many years after TR
001 was released, we have an updated SWOP 2006 #5 sheet
profile that
overwhelmingly agrees with the separations of U.S. Web
Coated (SWOP) v2.
Other than the fact that it puts 15 fewer points of
magenta ink into deep blues, I suppose. Just as the GRACOL profile
overwhelmingly agrees with US Sheetfed v2 other than the fact that it
assumes a third less dot gain.
In all printed materials I've seen of
yours, I think blue sky and water are decidedly too
cyan.
Good! Then you're part of the target audience for my
books. You need to realize that every profile other than SWOP v2 will
deliver blues that are too cyan, whereas the rest of us think that SWOP v2
delivers them that are too purple. Whichever way is correct, we need to be
aware of the situation and to take countermeasures as necessary.
I've been looking for quite a while now and haven't
seen this problem
for print conditions that this profile was intended
for. I have
normal vision. Your explanation?
A different form of color-blindness. The conventional
form is often called Daltonism; as the other visual-system deficiency has
no commonly accepted name AFAIK, I would propose that it be Murphyism,
unless you are too modest to lend your name to the syndrome.
The two forms have some similarities and some
differences. Daltonism has been clearly shown to be inherited; Murphyism is
thought to be acquired rather than genetic in origin, but whether it is
learned behavior or transmitted virally is not known.
The mechanism of the two defects is poorly understood.
In Daltonism, the theory is that a faulty eye structure renders it
difficult for the sufferer to distinguish color along the magenta-green
axis. In Murphyism, the awareness of machine readings is thought to have an
intoxicating effect, such that the visual signals from the optic nerve are
scrambled, resulting in a faulty evaluation of color generally.
Each syndrome has two major subgroups. A protanomalous
Daltonist will probably evaluate a green object as being lighter and of the
wrong hue, while a deuteranomoulous person may inquire of a friend whether
it is gray. This is similar to the timoromolous form of Murphyism, where
confronted with the same green but the belief that a machine has measured
it as being gray, the sufferer may make the same inquiry of a friend, if he
has one. Someone with bellicosus Murphyism, on the other hand, is likely
not only to insist that the green *is* gray, but to call anyone who
disagrees unpleasant names.
The deficiencies in each case are worse in certain
individuals than in others. Someone with a mild form of either Daltonism or
Murphyism may evaluate certain colors in a strange way but their conditions
may not be detectable by acquaintances. In some individuals, however, the
deficiency is so severe as to astonish normally-sighted people, such as
when a Daltonist cannot perceive the difference between an LAB image where
the A channel has been inverted and one where it is not, or when a
Murphyist cannot perceive that adding 15 points of magenta ink to a blue
makes it more purple.
Neither Daltonism nor Murphyism is disabling, and many
individuals of each variety enjoy normal and happy lives. As with the
purple shift in the SWOP v2 profile, however, it is well to understand that
the problem exists, and adjust one's life accordingly.
Dan Margulis
___________________________________________________________________________
Re: Color Management in Private Book Publishing
Posted by: "Jim Rich"
Sat Jun 30, 2007 9:01 am (PST)
Paul,
Ok. I get a better picture of this now.
My view today is that you generally don't want to
profile a press. Though you might be forced to. As I was for example with
the igens. There was not easy and repeatable method to apply the TVI or G7
method. Another reason is that the clients want it done that way because he
or she thinks it better than using canned profiles. Mileage always varies.
However, you definitely want to calibrate a press and
be sure there is process control.
While there are reasons to profile a press or presses,
if you use a good calibration method and bring the press or presses to the
same measured point say using LAB and midtone measurements of some kind, it
is then possible to use these more modern profiles.
In that scenario you want to calibrate the press and
then use a profile such as a ISO 12647 profile ( that does come with
Photoshop) , the Gracol 2007, SWOP 2006 or the new SNAP profile that is
available from the ICC web site (I believe) or the NAA website.
Here is an example of the type of methods I am taking
about. In the G7 method for a press calibration get the press under control
and do a press run where you have qualified (some how some way ) the ink,
paper and press combination to achieve proper ink film thickness to attain
the ISO specs. In that process the end-users uses colorimetery to measure
seven solids and 3 color cmy midtone patch. That is Cyan, Magenta, Yellow,
Black, Red (Y+M), Green(Y+C), Blue(M+C) and for neutral gray CMY using
50%cyan, 40% mag and yell.
To do this correctly based on the G7 method and to
create standardized results you need a use a Spectrophotometer to derive
the LAB values of the solids and midtone cmy values. These values are on
the Gracol.org website. After you get the LAB values then use densitometry
to verfiy the density values of those targeted areas when they were at the
proper LAB values.
So for those non believers, colorimetey does work and
can help to (1) standardize a color printing process (either a press or
proofer) and (2) you can optimize your color printing process. Then once
you get the process under control and optimized by the target numbers you
then might (or you might not) have to apply some color skill.
So the process for calibration or even profiles is not
as black-and-white are some what it to be. So if whoever is under impress
that people who buy into color management tools are bad or that people who
don't buy into color management or vice versa, then you have to get real
and see that color management does work.
There are color management set of practices and process
in place that work reasonably well and when the end-user hits the wall
because of technologies in this process then he or she needs to apply color
skill. As color technology has progressed over the last 10+ years, color
management has become a viable and practical solution.
When standardized calibration methods are used for
calibration it makes it technically easier for everyone in the process such
as publishers, designers, printers, photograhpers etc to aim for the same
target when creating proofs. Oh yea...then you can begin to use these types
of standard profiles in Photoshop for things like Soft proofing.
Enough for now.
Jim Rich
___________________________________________________________________________
Color Management in Private Book Publishing
Posted by: "Paul Foerts"
Sat Jun 30, 2007 4:59 pm (PST)
Jim Rich wrote:
Paul,
Ok. I get a better picture of this now.
I don't think so...
My view today is that you generally don't want to
profile a press.
Though you might be forced to. As I was for example
with the igens. There
was not easy and repeatable method to apply the TVI or
G7 method.
Another reason is that the clients want it done that
way because he or she
thinks it better than using canned profiles. Mileage
always varies.
However, you definitely want to calibrate a press and
be sure there is
process control.
An offset printing press cannot be
"calibrated" and therefore cannot be "profiled".
As you agreed that an offset press can be seen as some
kind of profile editor, how can you possibly claim that you can calibrate
and profile a profile editor???
Process control is what you need for predictable
production flows and maintaining quality standards.
The tools you mentioned in your post are process
control tools. These tools except the spectrophotometer have nothing to do
with "profiling".
Another list member, some time ago, called inkkey
setting "calibrating"...
As for the igens, these xerographic printers can be
calibrated and profiled. In theory they should be very stable...
For using these printers as "proofers", the
well known "eyeball-method" in combination with the printer's RIP
software (curves, saturation, contrast etc.) will offer an acceptable print
in minutes.
You can setup as many configurations as needed. This
way u can use the igen as printer (max saturation, extended gamut) or as
proofer (for whatever process intended).
For those, insisting on profiles: use the Xerox' canned
profiles. Maybe there is some kind of "easter egg" within the
software which lets you translate your eyeball setting into an icc
profile...
While there are reasons to profile a press or presses,
if you use a good
calibration method and bring the press or presses to
the same measured point
say using LAB and midtone measurements of some kind, it
is then possible to
use these more modern profiles.
Offset presses cannot be brought to the same measured
point. Printed sheets can, more or less, as different locations show
different values...
If you print 64 targets on one sheet, you may generate
64 different profiles. The profiling software offers you many variations to
choose from additionaly...
In that scenario you want to calibrate the press and
then use a profile such
as a ISO 12647 profile ( that does come with Photoshop)
, the Gracol 2007,
SWOP 2006 or the new SNAP profile that is available
from the ICC web site
(I believe) or the NAA website.
Calibrating offset printing presses with profiles??? As
far as I know, test forms do not use profiles. They are untagged. Maybe you
can include a tagged patch???
Here is an example of the type of methods I am taking
about. In the G7
method for a press calibration get the press under
control and do a press
run where you have qualified (some how some way ) the
ink, paper and press
combination to achieve proper ink film thickness to
attain the ISO specs. In
that process the end-users uses colorimetery to measure
seven solids and
3 color cmy midtone patch. That is Cyan, Magenta,
Yellow, Black, Red (Y+M),
Green(Y+C), Blue(M+C) and for neutral gray CMY using
50%cyan, 40% mag and
yell.
To do this correctly based on the G7 method and to
create standardized
results you need a use a Spectrophotometer to derive
the LAB values of the
solids and midtone cmy values. These values are on the
Gracol.org website.
After you get the LAB values then use densitometry to
verfiy the density
values of those targeted areas when they were at the
proper LAB values.
Readers are advised to visit the Gracol, SWOP, GATF,
Fogra, ECI etc. webpages to inform themselves about this issue.
So for those non believers, colorimetey does work and
can help to (1)
standardize a color printing process (either a press or
proofer) and (2) you
can optimize your color printing process. Then once you
get the process
under control and optimized by the target numbers you
then might (or you
might not) have to apply some color skill.
What you mention is "process control".
Colorimetry has a proven status. ICC colormanagement is a universal toolset
based on a black box (the color rendering engine) for color transformation,
using a standardized profile architecture (the ICC profile format). So
blackbox + profile will do the job for you. No color skill required...
So the process for calibration or even profiles is not
as black-and-white
are some what it to be. So if whoever is under impress
that people who buy
into color management tools are bad or that people who
don't buy into color
management or vice versa, then you have to get real and
see that color
management does work.
I suppose you use the word calibration instead
standardisation? Or do you mean process controll?
The best tool for color management is still
communication. All tools that work as promised are ok.
Paul Foerts
___________________________________________________________________________
Re: Color Management in Private Book Publishing
Posted by: Chris Murphy
Sat Jun 30, 2007 4:59 pm (PST)
On Jun 29, 2007, at 2:17 PM, Ron Kelly wrote:
Chris:
You and other calibrationists like Andrew Rodney say to
this problem:
this is a bad profile.
Among other things, you advise them to get a better
one.
OK, the term calibrationist is asinine. I've said it
before, it isn't useful. I consider it name calling and unprofessional. If
you guys want to behave like playground children, great. I'm not gonna
waste my time on it anymore.
I'm saying that if you're going to fly to San Francisco
when you really want to go to San Jose, you just need to be aware of the
consequences of flying to San Francisco instead of whining about how San
Francisco is so far away from San Jose. You can do that either by a.) going
to San Jose directly (i.e. separate with a profile that describes actual
output conditions), or b.) flying to San Francisco and taking a car to get
to San Jose (i.e. with a general purpose profile that's close to the
intended output condition, knowing you may have to tweak the resulting
separation).
Everyone should get a better profile, right? There's
printers out
there who do things properly, and don't support
companies that don't,
etc.
There are several issues with this advice:
-this profile was designed and implemented by
"experts"
For a specific printing condition, with specific inks,
with specific wet trap, paper stock, TAC, TVI, etc. It was not designed,
ever, as anything other than for the condition which it was built for. If
you are going to take a profile meant for a print condition with a
yellow/gray #5 paper, printing at 133 line screen and a 300% TAC and expect
it to work well on a #3 sheet, let alone a #1 sheet, BEST OF LUCK.
Seriously. A lot of printers have done work to make those separations work
well on those printing conditions because it's such a ubiquitous
separation, not because it's an ideal scenario.
You would have us get another profile or profiles,
constructed by
the same or perhaps other "experts" in which
of course we should
place our complete trust.
With time this profile will be replaced across the
broad spectrum of printing.
Hopefully the next standard will be better but it
wouldn't suprise me
if it wasn't.
You seem to want a magic profile. You seem to be under
the impression that printers don't print very differently from each other,
and that a single separation should work well for most any printing
condition.
About the closest you're going to get to that is GRACoL
7 right now. Ooops. It requires calibration, and a healthy dose of it
though. ISO 2846-1 inks, specific tone reproduction curve, specific gray
balance. And there is still an allowed deviation for the 50%+ end of the
TRC.
Chris Murphy
Color Remedies (TM)
New York, NY
___________________________________________________________________________
Re: Color Management in Private Book Publishing
Posted by: Chris Murphy
Sat Jun 30, 2007 5:00 pm (PST)
On Jun 29, 2007, at 6:36 PM, Ric Cohn wrote:
I must not be understanding something (and I would like
to). The
kinds of numbers you report are similar to my own
results. However,
for this deep blue you say the ink build isn't
significantly
different? Just from the ink numbers I would have
assumed they are.
The ink builds are different because one is for #5
sheet, the other #3. Different GCR, different paper white, and gain. I'm
saying their color appearance on their respective printing processes, or on
opposite printing processes (which is what I said I did in my previous
email) would not be that different. I'm not saying those builds on the same
print condition would yield the same color
appearance.
Interesting. It shows my need for more education, but I
don't
remember that US Web Coated V2 is based on #5 paper or
warnings about
using it for better paper. To tell the truth I'm not
sure what #3 or
#5 look like. Can you give me an idea of what magazines
use what? Is
Architectural digest a #3, or better? Is Parade a #5 or
worse? Isn't
a #5 stock significantly worse than most printing these
days (at
least where color is important)? To me, that alone
shows why
inadequate having only one profile to choose from is so
problematical.
U.S. Web Coated (SWOP) v2 is built from TR 001 which
was printed on #5 sheet as that's what SWOP had specified. In reality
today, many printers of magazines have been using something closer to a #3
sheet, if not outright using #3 with a brighter white and not as yellow. So
now there is modified data for #3.
If you look at where Europe is at in comparison, there
is now a FOGRA40. So they have 40 different characterization datasets. Of
course many of them are now deprecated. But the point is that yes it is
inadequate having only one profile to choose from.
I may be mistaken, but didn't Pantone change their
formulary in
recent years because their research showed that most
printing was
being done on whiter papers than when the formulary was
originally
developed?
Yes. But it's based on #1 sheet, 175lpi.
Chris Murphy
Color Remedies (TM)
New York, NY
___________________________________________________________________________
Moderator Warning--Civility
Posted by: Dan Margulis
Sat Jun 30, 2007 4:00 pm (PST)
Following the lead of John Ruttenberg in the Camera Raw
thread, members are hereby cautioned that effective right now,
contributions to the "Color Management in Private Book
Publishing" are subject to scrutiny for civility. Any instances of
namecalling, casting aspersions on motivations or intelligence of
opponents, or the like will result in the post being rejected.
There are currently three posts waiting approval. At
least one of these would not pass muster as stated above, but I am going to
approve them nevertheless because they were posted prior to this warning. I
will, however, wait about an hour before doing so, to make certain that
*my* message on civility gets out first. Any replies to the foregoing three
messages are subject to rejection if IMHO they take an unprofessional tone.
I would like to thank Jim Rich for his patient and
professional explanation of the process he goes through in attempting to
create repeatable quality at his press clients. I think that some of it is
misunderstood because different people assign different meanings to the
phrases "color management", "calibration",
"profiling", and "process control".
I would prefer not to use those words and instead
summarize the situation thusly: a printing press is a very unstable
instrument under the best of conditions. Quality-conscious printers go to
extreme lengths to make their work as consistent as possible. Regrettably,
there are not enough of these people.
This entire field can be roughly broken into two
pieces. First, deciding how we *want* the press to behave. Second, making
sure that it *does* behave that way, and that it continues to behave that
way tonight, tomorrow, next week, and until the end of time. For this
second goal, continued, extensive instrument readings of output are IMHO
absolutely essential. If the press can achieve stability and repeatability,
then any reasonable method of color management can get professional
results. If it can't, then *no* method of calibration, color management, or
profiling will work.
As to the first area, determining how the press
*should* behave, and as to how the files should be separated to make sure
that it does so, that's where mileage can vary. Personally, I find machine
input nearly useless in this area, but others differ.
Dan Margulis
___________________________________________________________________________
Re: Color Management in Private Book Publishing
Posted by: Chris Murphy
Sun Jul 1, 2007 9:06 am (PST)
On Jun 30, 2007, at 10:58 AM, DMargulis wrote:
Excellent example. The weak inks, yellow and black,
have little influence on
the color. The blueness vs. purpleness depends almost
exclusively on the ratio
of cyan to magenta ink. In these two, the cyan values
are the same but in one
case the magenta value is 15 points higher than the
other.
Again, I'll point out that you're comparing #3 to a #5
sheet and suggesting that I've said that 15 points won't make a difference
on the SAME printing process. Not true, I explicitly said I had assigned
the OPPOSITE profile to BOTH sets of values before converting back to LAB.
This wipes out the fact you're making an apples to oranges comparison
because the two data sets are different as are the stocks.
The black does actually affect the color quite a bit as
does the yellow and gray in the paper on a #5 sheet. So you're wrong.
Again.
If we go with an equal distribution (which isn't
exactly how it works, but it's closer than totally ignoring it as Dan has
done), we should add 44% to each C, M, and Y in the first case, and 66% to
each C, M, and Y in the second case. We get:
144c, 126m, 73y
and
166c, 133m, 72y
144c,126m translates to 87% magenta component relative
to cyan.
166c,133m translates to 80% magenta component relative
to cyan.
So it's actually a 7% difference between them. Not 15%
as you've
claimed. And it's a rather dark color, L* 19-22. We
aren't as sensitive to dark colors. And add in the fact it's not that
saturated once in CMYK anyway with all the gray component (the yellow, gray
paper and all that black), and it's not a surprise these colors end up
being more different in lightness and chroma than in hue.
Denying that adding 15 points of magenta ink to a blue
shifts the
color toward purple is reminiscent of your defense of
the
impossibly high dot gain specified in the Photoshop
U.S. Sheetfed
profile, see
http:
//www.ledet.com/margulis/ACT_postings/SeparationIssues/ACT-Web-vs-Sheetfed.htm
1.
OK so you get to bring up a previous, unrelated point
and I will yet again explain my position:
I used that U.S. Sheetfed Coated v2 profile in a
Seybold profiling package shootout some number of years ago. It's
measurement data was from an analog proofing system made from film. I used
it on a Matchprint system supplied by Creo using a Trendsetter. And it made
a very nice reproduction on that proofing process. In fact, I gave it the
top score compared to CUSTOM profiles for that same proofing process
because it produced, at the time, the smoothest separations,
among some other attributes.
So you can complain about that profile until the cows
come home, but that profile made a separation that worked very well on a
site unseen analog proofing system. Once again you're entitled to your own
opinion, but not your own facts.
2.
And now I get to bring up a previous, unrelated point
and we'll see if you explain your position:
You said you have a spreadsheet that reveals the exact
math of ACR. When are you going to provide it?
I assume that your argument remains the same: 15 points
of extra
magenta in a blue is no big deal, overestimating the
dot gain by a
third is no big deal.
If we normalize to account for GCR, the difference is
actually 7 points. And my method explicitly accounts for the fact these are
two different printing processes. Your purporting that the same values made
with two profiles for two printing processes printed to the SAME printing
process is somehow an appropriate comparison. You're ignoring that the two
profiles are for different data sets and paper types.
The original L* in this example was 7, the resulting L*
in print is predicted to be around L* 19-22 which is very dark and the
human visual system is not very sensitive to hue shifts in colors with low
lightness. So perhaps we need a different color to talk about, but you said
this one is excellent so I'll just stick with it:
Original color (dark blue, which might as well be
nearly black as it has about 4% reflectance):
7L*,4a*,-54b*
Converting to two profiles. The first uses TR 001
unmodified. The second uses slightly modified, updated data, and a new
profile building algorithm. Both data sets are based on #5 stock.
U.S. Web Coated (SWOP) v2
100c,82mc29yc44k
SWOP 2006 Coated5v2
100c,70m, 3y,63k
Reverse the profiles and see what each says about the
other:
According to the SWOP 2006 Coated 5v2 profile,
100c,82mc29yc44k has a LAB value of 22, 1, -19.
According to the U.S. Web Coated (SWOP) v2profile,
100c,70m, 3y,63k has a LAB value of 19, 1, -21.
Again, the data sets between them aren't identical. The
2006 version has slightly updated values, but not much. And as you can see,
each profile predicted the OTHER PROFILES CMYK values as not being all that
different.
Delta E 2000 2.32
Delta H 0.13
Delta C 2
Delta L 3
There's no disputing the newer profile does a better
job, due in large part to the higher GCR allowing for a dark and more
saturated version. But the hue error between them is rather over stated by
Dan. In my view, he's simply wrong.
Chris Murphy
Color Remedies (TM)
New York, NY
___________________________________________________________________________
Re: Color Management in Private Book Publishing
Posted by: "Dennis Dunbar"
Mon Jul 2, 2007 11:24 am (PST)
Just as an exercise I created an image and filled half
with the first color (100c,82mc29yc44k) and filled the other half with the
second color, (100c,70m, 3y,63).
In comparing the appearance of these colors I really
was surprised to find the second color appeared decidedly MORE purple than
the first even though it had LESS magenta.
It appears that the magenta component in this
particular mix is not influencing the apparent hue nearly as much as one
might think.
When I created the image I used the U.S. Web Coated
(SWOP) v2 for the image and then just for grins tried assigning various
CMYK profiles to it to see if this result was just due to the way that
particular profile handled things. Interestingly the only profiles that
showed the first color as more purple were the Photoshop 4 Default CMYK and
Photoshop 5 Default CMYK profiles. Everything else I tried showed the
second color as more purple, (except for the Japan standard v2 which showed
them as nearly identical).
Dennis Dunbar
___________________________________________________________________________
Re: Color Management in Private Book Publishing
Posted by: Dan Margulis
Mon Jul 2, 2007 11:24 am (PST)
Chris Murphy writes,
So it's actually a 7% difference between them. Not 15%
as you've claimed.
As you concede the method of computing that is somewhat
rough so the real number is higher. However, in the interests of closure I
will accept for the sake of argument that SWOP v2 only puts 7 points more
magenta in deep blues than SWOP 3 2006 does.
Even if SWOP2006 were taken to be accurate, a variation
toward purple of 7 points from it is more than twice the difference that a
quality-conscious user should tolerate. In fact, however, SWOP2006 is
itself substantially shifted toward purple in blues, although one can live
with it.
To summarize, and then I think the topic can be closed,
1) For many years a vociferous group has strongly
denied that SWOP v2 shifts blues toward purple. There has been no previous
claim that it should only be used for certain types of paper, only that it
is the correct default to use for all SWOP conditions, and that the profile
has been verified by machine measurement, which has shown that these
obvious purples were really blues. I have said that the profile is usable
but that the purple shift in blues needs to be taken into account during
color correction.
Result: the new profile that we all appear to agree is
better puts drastically less magenta in blues.
2) For many years, substantially the same group has
inexplicably taken the position that the default Photoshop sheetfed
profile, which is obviously wrong in that it produces much lighter
separations than the default web profile does, is in fact correct. Unlike
the SWOP v2 profile, which merely has a defect that can be worked around,
the misstatement of dot gain in this profile is so enormous as to make it
unusable professionally. To this statement, there has been considerable
namecalling and assertions that the profile would work on any sheetfed
press on which it would work, and that it is perfect because it was
personally made by a person who never makes mistakes.
Result: the new profile that we all appear to agree is
better lops a third off the assumed dot gain of the Photoshop sheetfed
profile. This enormous amount is around five times more variation than a
quality-conscious user would tolerate.
The threads where the arguments were made are posted at
http:
//www.ledet.com/margulis/ACT_postings/SeparationIssues/Separation.htm
Dan Margulis
___________________________________________________________________________
Re: Color Management in Private Book Publishing
Posted by: Mark Segal
Mon Jul 2, 2007 1:55 pm (PST)
Before you rush to close the topic, you may recall that
you posted a response to my initial message which started it. You made a
number of points there that I have not answered yet, because they required
me to seek additional information from source - in order to verify certain
issues and remain factual. That information is now coming together and I
shall be preparing a response based on what I am receiving. It will not
cover all these fine points about the characteristics of various profiles
into which this topic developed and about which others know much more than
I do, but it will revert to the specifics of our two original messages.
Therefore I recommend it may be useful to members if you were to leave the
topic open for a bit.
Mark Segal
___________________________________________________________________________
Re: Color Management in Private Book Publishing
Posted by: Dan Margulis
Mon Jul 2, 2007 8:20 pm (PST)
Dennis writes,
Just as an exercise I created an image and filled half
with the first
color (100c,82mc29yc44k) and filled the other half with
the second
color, (100c,70m, 3y,63). In comparing the appearance
of these colors I
really was surprised to find the second color appeared
decidedly MORE purple than the first even though it had LESS magenta. It
appears that the magenta component in this particular mix is not
influencing the apparent hue nearly as much as one might think.
There's plenty of hue change there, but it's masked by
some extraneous factors. You can see it more easily as described below.
First, the whole discussion of this color is of little
utility except for the blueness/purpleness question. The original color
Chris proposed to convert to CMYK was 7L4a(54)b, which is wildly out of the
gamut of any known output device, let alone something blue-deficient like a
SWOP press. According to the SWOP v2 profile, If you start with 7L4a, the
bluest printable value you can have in the B channel is (33)b.
The color being asked for is therefore around twice as
blue as the press can accommodate. Anybody who leaves such a value in their
RGB or LAB files before converting to CMYK deserves whatever they get in
print, IMHO. *No* profile can handle something this far out-of-gamut except
by blind luck. Consequently, the SWOP2006 version is drastically different
from the SWOP v2 version--it's much darker and much more saturated. Who's
to say which one is right? They're both trying to match something that is
far beyond their capabilities of matching, so the question of which
approach is "right" has no answer.
You can verify in the Info palette that the SWOP 2006
version is both bluer (with SWOP v2 used as the assigned profile, (33)b vs.
(29)b), and more cyan as opposed to purple ( (1)a as opposed to +1a). It
is, however, hard to see the difference in blueness on screen for the
following reasons:
a) When they're side by side, given how much darker and
more saturated the SWOP2006 version, simultaneous contrast causes us to
evaluate the duller, lighter SWOP v2 version as being even grayer, less
colorful.
b) The SWOP2006 version uses a much heavier black build
in this area, and no profile does a very good job of representing the
impact of black on a monitor.
c) When viewing it with either SWOP2006, SWOP v2, or
most other machine-generated CMYKs, you are getting a misleading preview
because these profiles are not accurate with respect to deep blues. The
preview you are seeing is therefore bluer, less purple, than it is on
press.
To get a more valid read on which one is purpler and
which more cyan, put the swatches on two different layers, rather than side
by side. Put the SWOP v2 version (the lighter, less saturated one) on the
top layer. Then toggle back and forth between Luminosity and Normal as your
layer mode. When Normal mode is in effect, you see the SWOP v2 version.
When Luminosity mode is in effect, you see the color of the SWOP2006
version with the same darkness as the SWOP v2 and, critically, the same
style of black generation. Now most of the distractions are gone and you
can see easily that one is more purple (or, if you like, the other is more
green).
On my system, doing that gives 17L1a(29)b for the SWOP
v2 version and 17L(4)a(23)b for the modified SWOP2006 version. That's a
huge shift, but Chris was right when he said that the darkness of this
color masks its hue pretty well.
Dan Margulis
___________________________________________________________________________
Re: Color Management in Private Book Publishing
Posted by: Dan Margulis
Mon Jul 2, 2007 8:20 pm (PST)
Mark Segal writes,
Before you rush to close the topic, you may recall that
you posted a
response to my initial message which started it. You
made a number of points there
that I have not answered yet, because they required me
to seek additional
information from source - in order to verify certain
issues and remain factual.
That information is now coming together and I shall be
preparing a response based
on what I am receiving.
I was not intending to close the thread, if I had
wished to do so I would have stated it unambiguously. I was speaking for
myself alone, and limiting it to the characteristics of two specific
profiles that have been discussed at inordinate length on this list over
the years. The most recent profiles are significantly changed to correct
the deficiencies that others denied existed in the first place.
From my POV the changes for the better in these new
profiles speak for themselves and require no further commentary from me,
although I daresay mine will not be the last word. I was not asking anybody
else to refrain from posting about it, although the list has been cautioned
that posts on this topic that use unprofessional language will not be
approved.
Your original post had nothing to do with these
specific profiles, as I recall. If you interpreted my message as asking you
or anybody else not to pursue it further, I apologize, as this was not the
intended meaning.
Dan Margulis
___________________________________________________________________________
Re: Color Management in Private Book Publishing
Posted by: Mark Segal
Tue Jul 3, 2007 3:32 am (PST)
Hi Dan,
Fair enough - it seemed like a "generic
statement" so I wasn't clear on whether it applied to part of the
discussion or all of it. Thanks for clarifying the intent. And you recall
correctly - my original post did not get into the technicalities of the
profiles - this is/was an interesting further development arising out of
the initiating topic.
Mark Segal
___________________________________________________________________________
Re: Color Management in Private Book Publishing
Posted by: Stephen Marsh
Thu Jul 5, 2007 3:01 am (PST)
Hello again Chris, sorry for getting back late on this
topic, I have been busy and pressed for time.
As this is a long reply to two earlier topic replies, I
will break up the text into sections with ====== equal signs.
======
Stephen Marsh wrote:
In fact, all of the "2" presets use the
"ignore profile/honour values"
method. It would appear that Adobe agree with my
position as a defalt.
Chris Murphy wrote:
It ignores embedded profiles in placed CMYK objects.
Yes agreed, this is the behaviour of the "safe
CMYK workflow" of which I am speaking.
Sorry for not being crystal clear, as CMYK images and a
safe CMYK workflow was being discussed, I did not think that I had to
qualify my reply for working RGB as well, where a conversion to output
space is required from a synthetic RGB editing space.
No argument from me here.
======
Chris Murphy wrote:
Everything else is tagged. And by default those CMYK
objects, usually from
Illustrator or Photoshop, are tagged. The InDesign
document is
tagged. Color appearance is preserved through the
embedding of these
profiles. It's been going on for two years.
Even if the CMYK tags are in the file, as you say -
they are ignored when using the safe CMYK workflow in InDesign CS2 or
Illustrator CS2 or later, so it does not matter to the output whether an
application "usually" tags or not.
I don't think that we have a huge argument or
disagreement on this general point Chris.
======
Stephen Marsh wrote:
I am not saying this should never be done (convert
values), just that
it is not a good default to convert CMYK values just
because two
profiles don't match (which is my understanding of CS
or earlier
workflow if enabling preserve CMYK profiles and there
was an image and
document mode mismatch printing composite CMYK or CMYK
seps).
Chris Murphy wrote:
Yes but this wasn't a default behavior.
So you agree with the yes that in this case, a profile
conversion does indeed take place. I can see that this exchange is being
made harder with my word choice and with lexical semantics.
OK, so we have agreement on the technical content of
how the app works - just not on the choice of the word 'default'.
======
Chris Murphy wrote:
Output doesn't get screwed up due to the image profile
not matching
the output profile.
Stephen Marsh wrote:
This does not match the results from the test that I
have just
performed using the colour management policy for
"Preserve Embedded
Profile". This was the only colour managed colour
option before CS2
introduced the "safe CMYK Workflow", when
using this policy colours
are converted if the image profile does not match the
document profile
when printing/exporting to PDF.
Chris Murphy wrote:
Yes the colors are converted. But again, that is not
synonymous with
output getting screwed up.
Fine, general agreement again - that there is a
conversion under these special circumstances.
======
Stephen Marsh wrote:
My black only element (image) tagged with legacy Max
GCR was
reseparated to SWOP v2 (document profile) when output
when using the
preserve embedded CMYK profile option.
Chris Murphy wrote:
This is an example of one of the known areas where
repurposing CMYK
is problematic.
OK, we generally agree again, you just have more faith
in process control and repeatable results than I do.
======
Chris Murphy wrote:
If rigorous process control is in place and
registration is
excellent in most instances there would be no problem
with such
repurposing.
Stephen Marsh wrote:
Qualified with a very big if Chris.
Chris Murphy wrote:
Hey it gets done in Europe with much greater regularity
than here,
and they have older presses in a lot of cases than we
do.
We will have to agree to disagree on this point Chris,
it is not worth arguing over.
"If" and "Most instances" simply
does not cut it for me, my world is not as ideal or perfect as yours.
======
I'm sure a lot of people had a laundry list of "oh
that
should have been in 1.0, what were they thinking?"
Let's get real.
I am "being real" Chris, although I am well
aware that hindsight is always 20/20.
======
The fact of the matter is, color management wasn't on
by default
until CS2.
OK then, I take you word on it Chris, up until CS2 I
only rarely used it for service provider jobs that were not setup in Quark.
Since CS2, I build all new art in AID and now Xpress files are rare for
service provider work. How times change.
And yes, even though I often use RGB and CMYK profiles
in Photoshop, I have no need for CM in illustration and layout so CM was
set to off in earlier versions and times. Today, RGB is preserved and safe
CMYK is in use.
Chris Murphy wrote:
It would have been a very good thing to have the
Preserve
Numbers policy there earlier than CS2.
But it became a requirement as a result of the decision
to turn
color management on by default.
Agreed
======
Stephen Marsh wrote:
I submit that there have been no problems becuase by
default these
General Purpose 2 colour settings presets *use safe
CMYK by default* -
so there will be no problems like I am talking of
(unwanted
reseparation of CMYK elements based on their tag).
Chris Murphy wrote:
Yeah, OK.
Agreed again, safe CMYK is the best out of the box
setup for CMYK work - those that do need to reseparate on the fly for
various conditions can also do so if they wish. Both are happy.
Stephen Marsh wrote:
Are you saying that it would not be considered a
problem if one was
using the "preserve embedded (CMYK) profile"
policy, imported a legacy
Max GCR K only tagged file with K only elements into a
document
profile of SWOP v2 and printed CMYK separations or
composite CMYK?
Chris Murphy wrote:
No.
We will have to disagree here then Chris.
======
Chris Murphy wrote:
That we even still dealing with CMYK at the front end
at all is a
testimony to how unsophisticated our applications,
workflows, and
process control really are.
Stephen Marsh wrote:
Is having precise control unsophisticated?
Chris Murphy wrote:
No.
Stephen Marsh wrote:
This is what working in final device space with no
conversions give
those that require it - precise control.
Chris Murphy wrote:
The argument that the only way to get it is via CMYK is
demonstrably
false. That you can get precise control on something
like most press
conditions today is laughable.
I was talking of precise control in prepress and file
preparation, not on press.
RGB comes close, but is no substitute for working in
final space. If it was, we would all be working in RGB and letting the app
do the conversion to CMYK - but this is not the case. I think Dan wrote an
article about this which I will try to dig up.
Just because one can work in an intermediate space that
is not the final one, should we? For some folk and jobs the answer is yes,
for others it is no.
======
Stephen Marsh wrote:
If you still hold this position, despite my examples
above, then we
will have to agree to disagree on where the problem
lies Chris.
Chris Murphy wrote:
The example isn't even remotely compelling at this
point.
Not compelling? OK. You wrote earlier -
"This is an example of one of the known areas
where repurposing CMYK is problematic."
So problematic, but not compelling.
======
Chris Murphy wrote:
"Numerically correct" applies only to a
specific printing condition.
Stephen Marsh wrote:
That is all that I am talking of Chris.
Chris Murphy wrote:
Give then wide assortment of printing conditions due to
paper, ink,
resolution, screening algorithms, it is usually a guess
the size of a
barn door as to what that print condition actually is.
Not a barn door when working to a target condition from
specifications from the print shop.
The problem in this discussion has been that I am only
talking of printing for a single known condition - where as repurposing for
other different print conditions has also been introduced.
I think that we both agree on each separate general
point, but there is too much confusion with two separate workflows being
spoken of.
When no repurposing is going on and the print condition
is known and true - one does not wish the files CMYK values to be altered,
they are correct as they currently are, that is why they are being used in
the first place!
When it is wanted and repurposing is being done on
purpose, profile conversions can be of great help.
======
I have snipped further replies about
"default" as it only serves as a distraction to the valid points
in our discussion.
Sincerely,
Stephen Marsh.
___________________________________________________________________________
CMY vs RGB/CMYK Input for CcMmYK Inkjet
Posted by: Stephen Marsh
Thu Jul 5, 2007 7:36 am (PST)
Stephen Marsh wrote:
Even in such conditions, it can sometimes help to work
in CMYK (even
if the RIP is CcMmYK). I have had one specific problem
with inkjet
colour builds for dark coloured areas in one job that I
recall and the
only thing that helped was a CMY only separation so
that the RIP would
not lay down any K at all and only use CcMmY for this
area (a persons
face in shadow under a hat brim).
Chris Murphy wrote:
Most fine art photographic printing is done with RIPs
that do not accept CMYK. They receive RGB data only, and perform their own
separation internally.
The example doesn't reveal the device, RIP, paper,
inkset or any of
the settings used, or how the file was converted to
CMYK to begin
with and what black generation settings were used. So
as provided I
don't find it persuasive that working in CMYK to
produce a CMY
separation wasn't simply a workaround for a problem
introduced in a
previous step. And it's that problem that should be
rectified.
Chris, for clarity - I have separated this part of an
earlier exchange into a new thread.
I did not take note of "fine art", my
comments were about more general
wide format multi ink printing via inkjet technology.
To answer your questions:
Printer: HP DesignJet 5500, wide format CcMmYK
RIP: ColorBus Cyclone...
Stock: HP Photo Gloss
Inkset: OEM CcMmYK Dye based ink
Settings: Too hard to go into. It does not use ICC
profiles, but MLT or multi ink lookup table files (being a 6 ink unit).
Some questionable CMYK ICC profiles of this device are available from the
vendor, but are not used for printing.
The original image *was* RGB, not CMYK. The GCR method
used in the RIP or direct in the printer if going PCL rather than
PostScript was putting down too much black in the shadowed face. The black
was having mottling effects, giving rather unpleasant skin.
A light GCR or perhaps UCR was then used in a CMYK
file. This reduced the problem but did not solve it.
In frustration, I then made a dupe and converted to No
K generation GCR and masked in this area into the Light GCR file so that
only the shadowed face area was CMY while the rest of the image had a
skeleton K plate.
This is what worked. I don't know how such CcMmYK
devices handle incoming CMYK data, if it is internally reseparated from an
assumed or honoured profile to the device inks or if it only messes with
the CMY and not the K device link style etc. All I know is that by not
having any K in the source file, or RGB for that matter and only CMY data
in a CMYK file that things worked for this one very unique situation.
Not an everyday problem, but when facing a deadline it
is nice to know that one can use CMY(K) mode files to overcome a problem
that time does not allow one to fix - even in a CcMmYK device that may
often be fed sRGB, Adobe RGB or SWOP CMYK data.
Stephen Marsh.
___________________________________________________________________________
Re: Color Management in Private Book Publishing
Posted by: Mark Segal
Sat Jul 21, 2007 6:31 am (PST)
Hello Dan,
I have delayed responding to this message because it
required that I verify some information and it took a while to get the
answers back. The purpose of this response is to clarify some possible
misunderstandings, rather than to carry a debate about what you really
meant or didn't mean in that 1999 article. I did of course read it several
years ago, I re-read it when it was referenced in a recent thread (which
prompted my original contribution), then I re-read again in light of your
response.
The theme of a "universal language" for
colour management is exactly what I understood you were talking about then
and what I was addressing in my OP, so let us make sure we agree about the
meaning of that term. The basic idea is that by using properly made ICC
profiles under the conditions for which they were made, the hues,
brightness and saturation I see on my monitor should be *the same* as those
that emerge from my inkjet printer and should be *the same* as those that
emerge from the printing press as a finished product (for example a book).
When we say *the same* we don't mean *identical*, but we mean as close as
technically possible given inherent differences in the light emitting or
light reflective qualities of the hardware and papers we are working with,
which no profiling method can bridge 100%. To achieve this, the monitor,
the inkjet printer and the printing press are all profiled - these days
with heavy reliance on "machines", such that when the
photographer tweaks the files according to what he/she sees on his/her
monitor, he/she has confidence that the resulting image from the inkjet and
the press will be *very similar* and therefore acceptable. I hope we agree
this is the objective of the *universal language* and that the profiles and
contemporary profiling methods are there to achieve it.
The technical means by which the overwhelming majority
of these profiles are made is the use of spectrophotometry. In the better
packages, the software supporting the spectrophotometry includes controls
to edit the profiles. I assume this combo of hardware and software is what
you mean by "machine-made".
My understanding about "the claim" of colour
management is that making and using profiles properly, with instruments and
related software, there will be a high degree of colour predictability and
consistency from any of a multitude of devices that are so profiled. The
short-hand below for this understanding is the *claim*.
You mention in your response to my OP that you said in
1999 the overall concept of this *claim* would fail, and now you imply you
see no reason to change that view. I hope I have understood you correctly
in this, but if not I have no doubt I can count on you to say so. In my OP
I was presenting evidence to suggest that the claim of colour management
seems successful, and we'll revert to that shortly. I agree you did say
"Color management is dead; long live color management", but that
was in the context of a number of other things you said:
“The old-fashioned way of guessing at the
settings and then tweaking isn?t just easier, it?s better. (This goes for
making ICC profiles, too.) And the more different the devices one is trying
to calibrate, the bigger the gain by forgetting about what the opinion of
machines may be.”
“The suggestion about profiling presses is also
characteristic of the approach of some ICC advocates, who often, like the
Adobe programmer, lack real-world production experience. The idea makes
sense--it's just very naïve. Despite advances in technology, trying to
fingerprint a modern press is like trying to profile the wind. Anything you
come up with will be obsolete in an hour, or the next time paper gets
changed or any one of a hundred other variables do.”
“So it is with ICC color management. It has found
its niche, as a worthwhile way for a “small minority of people to do
certain things. As a universal interchange format, it's dead.
It is those three statements that I think the recent
experience with private book publishing puts under the microscope.
You question in your response to my OP whether the
presses under discussion use "machines" to create their profiles
and whether having done so they edit them; for the record here are the
facts.
Four press houses were surveyed at my request: two in
the Far East, one in Canada and one in the USA. One of them did not respond
yet, but the answer from the others is yes and yes, and there is good
reason to believe the non-respondent one does too. Here are extracts of the
answers received:
From one house:
"Our entire colour process from proofing to
printing uses ICC profiles. These profiles are created by running certain
images and a target on press. After the press sheet is run the same images
and target is run through our proofing process. The targets on both the
press sheet and the proofs is read using a spectrophotometer. The data we
need to create an ICC profile comes from measuring and comparing the
differences in these two targets. The reason the press sheet is run first
is close the loop and insure that we have predictability in our proofing
and printing process. Based upon our findings we come up with an ICC
profile that is applied to or used in converting customer supplied files..
..............
"The ICC profile allows us to run consistent,
standard densities on press to match the Contract proofs that the customers
have reviewed and signed off on. That being said, there are still times
when the press operator will adjust these densities to better match the
proofs and the customers expectations."
From another in response to my questions:
“(2) Do they use electronic instruments to create
these profiles?"
Yes, there are special tools we use. At our prepress
house ...., we use Monaco profiling software, along with a
spectrophotometer to read the IT-8 charts."
“(3) If yes, do they also need to adjust the
profiles manually afterward?
Sometimes. Profiles can be "peaked into" if
you really know what your doing. They carry information about the printing
press such as dot gain and standard ink density, but other information such
as setting the amount of GCR (gray component removal) is a more of a choice
in philosophy than an artifact of the printing presses."
The bottom line from these inquiries is that
machine-based ICC profiling is the backbone of their colour management
operations, with occasional editing. If you are trying to suggest that the
occasional editing invalidates the colour management *claim*, then we will
just have to agree to disagree. If you are suggesting that the colour
management *claim* excludes the need for any editing and on that basis you
say it wouldn't happen, we agree, but I would suggest that's a straw-man.
You appear to be suggesting below that the experiences
of Reichmann and Allen which I described in my original message is not a
validation of the colour management *claim* for two reasons: (i) in one of
the experiences you say what the client did disproves the *claim*: and (ii)
these people are somehow exceptional because they know what they're doing:
Quoting from your reply: <<one of these people explicitly went away
from the machine-generated profile (if that's in fact what it was). He saw
proofs, wasn't quite satisfied with the appearance, and proceeded exactly
as he would have in the 1980s: he summoned an experienced colleague (human
being, not a machine) to adjust the settings manually.>> (In this
case you had to have been talking about Bill Allen); and: <<The
question is, are the practices of these two consistent with "a small
minority of disciplined users", or of "a universal language of
color", accessible to great and small? It looks to me like the
former,............."
Let's dismiss the second issue first, because it's
shorter and easier: Dan, if I were to put colour management into the hands
of my 5 year old grandson with the best ICC profiling in the world the
result would be a mess, and he's a smart kid. Back to serious - you can't
invalidate a claim on the strength of an argument that the process will
break if put into the hands of people who aren't competent to use the tools
properly. The point is that the tools are there and they work, so
"universality" is accessible - as long as people use the tools
competently. Telephone service is quite universal but ya gotta know how to
dial the phone. These tools and techniques are increasingly accessible to
more and more people - the numbers will increase over time, but whether its
today's numbers or the numbers ten years from now the universality of the
language is there for those who choose to speak it. I don't know that any
serious party ever suggested we can park our brains at the door and just
push buttons. You can't do that in Photoshop either, yet tens of millions
of people are using this universal platform for editing images.
On the first issue, you've misunderstood. What you said
neither reflects what I described, nor what Bill Allen did. On request,
Bill further clarified and permits me to cite here: : "One quick
thing, ........... my comments on my seeking of 'advice.' That occurred
long before submitting anything for press or even talking to the people at
the press. Those discussions were aimed completely at making sure that my
photographs were within acceptable ranges............... The job would have
looked fine if we hadn't done anything except crank up the press. There are
personal preferences for a specific look in a book, however, that are not
reasonable for any system to anticipate, and are also not necessarily going
to be either better or worse than the 'standard' that would be derived from
the types of system utilizing computer controls. It's just a
'preference.''" and for further clarity: "I didn't
"summon" those 'experienced people' to make changes while we were
running. Those 'experienced people' were over a thousand miles away
.................. I had talked with them over a month before.....,
.......... "I did what anyone would do when the job was on press:
discussed the very small changes that I wanted on a very few pictures to
match my personal preferences with the press people, saw the changes, and
went back to .........the customer's room." This says nothing
substantively different from what I reported
I think we converge on the point that with the huge
reduction of cost that has occurred, modern tools and techniques are vastly
opening the market of private book publishing ventures on a global scale. I
believe that electronic devices and related software are also making a very
substantial contribution to this outcome, to an extent that may not have
been so easily foreseen even ten years ago.
Mark Segal
___________________________________________________________________________
Color Management in Private Book Publishing
Posted by: "Paul Foerts"
Sun Jul 22, 2007 4:23 pm (PST)
Mark Segal wrote:
...
Four press houses were surveyed at my request: two in
the Far East, one in
Canada and one in the USA. One of them did not respond
yet, but the answer
from the others is yes and yes, and there is good
reason to believe the
non-respondent one does too. Here are extracts of the
answers received:
...
Hi Mark,
Please ask these printers to supply you
"their" press profiles. Use these profiles to optimize your RGB
"test image" on your monitor. Proof these images on your printer
using their profiles... Let these printing houses proof your RGB "test
image" (without showing them your proofing result). Compare
"theirs" with "yours". If all proofs match, your color
management test was a success... (Most printers can match their proofs with
their presses)
Kind regards,
Paul Foerts
___________________________________________________________________________
Re: Color Management in Private Book Publishing
Posted by: Dan Margulis
Tue Jul 24, 2007 9:33 pm (PST)
Mark Segal writes,
The theme of a "universal language" for
colour management is exactly what I
understood you were talking about then and what I was
addressing in my OP, so
let us make sure we agree about the meaning of that
term. The basic idea is that
by using properly made ICC profiles under the
conditions for which they were
made, the hues, brightness and saturation I see on my
monitor should be *the
same* as those that emerge from my inkjet printer and
should be *the same* as
those that emerge from the printing press as a finished
product (for example a
book). When we say *the same* we don't mean
*identical*, but we mean as close as
technically possible given inherent differences in the
light emitting or light
reflective qualities of the hardware and papers we are
working with, which no
profiling method can bridge 100%. To achieve this, the
monitor, the inkjet
printer and the printing press are all profiled - these
days with heavy reliance
on "machines", such that when the
photographer tweaks the files according to
what he/she sees on his/her monitor, he/she has
confidence that the resulting
image from the inkjet and the press will be *very
similar* and therefore
acceptable. I hope we agree this is the objective of
the *universal language*
and that the profiles and contemporary profiling
methods are there to achieve
it.
No, we do not agree. "Universal language" was
the term used to describe the embedding of a tag that would, so said its
supporters, endow each file with device-independent, unambiguous
colorimetric information that would render further communication, such as
took place in this case, superfluous. The promise of the "universal
language" was that simply embedding the tag in an RGB file would
guarantee consistent output anywhere in the world.
The promise of the "universal language" was
that case-by-case discussions with printers would be eliminated. Because
that concept failed, these two authors had to spend a good deal of time
with the printer's representative, just as they would have 15 years ago.
The promise of the "universal language" was,
as Photoshop documentation of the time put it, an "all-RGB
workflow." It was theorized that CMYK was poisonous, that
photographers did not wish to know anything about it, and that this dirty
business was the responsibility of the printer, presumably at the RIP
stage. Because that concept failed, these two authors supplied files in
CMYK, just as they would have 15 years ago.
The promise of the "universal language" was,
as pointed out in the article, that all files would be subject to
conversion by strangers. Because that concept failed, these two authors
supplied files in press-ready CMYK, where any conversion would be an error,
just as they would have 15 years ago.
The technical means by which the overwhelming majority
of these profiles
are made is the use of spectrophotometry. In the better
packages, the software
supporting the spectrophotometry includes controls to
edit the profiles. I
assume this combo of hardware and software is what you
mean by "machine-made".
No. By machine-made, I meant machine-made. No human
intervention, no editing, no revision, no alteration, no way, no how. While
nobody AFAIK still endorses it, a common theory in 1999 was that the
machine was more sensitive than the human eye and that any attempt to
override its decisions was self-defeating.
As for the use of machine measurements as a *start* to
a profile, with later human intervention as needed, I am aware of at least
one such package dating from 1978. Measurements to start a profile were
common in the 1980s and commercial packages were available in the early
1990s.
My understanding about "the claim" of colour
management is that making
and using profiles properly, with instruments and
related software, there will be a high
degree of colour predictability and consistency from
any of a multitude of
devices that are so profiled.
That would be like claiming that ICC profiles enable us
to use desktop computers. Predictable color across a broad gamut of devices
was well established in the professional community long before 1999.
From one house:
(3) If yes, do they also need to adjust the profiles
manually afterward?
Sometimes. Profiles can be "peaked into" if
you really know what your doing.
They carry information about the printing press such as
dot gain and standard
ink density, but other information such as setting the
amount of GCR (gray
component removal) is a more of a choice in philosophy
than an artifact of the
printing presses.
There is the crux of the issue--the area in which we've
seen great improvement, just as predicted in my 1999 article. Making a
profile without machine measurements is for people with a lot of experience
in the area. Printers have much better use for the time of such individuals
than constructing basic profiles. If possible, such experts get called in
late in the process to correct obvious deficiencies.
In 1999, the basic profiles that the machines were
generating were by and large worthless. An experienced person might as well
have started from scratch. An inexperienced person using one of the
packages would be stuck with poor calibration.
Today, as predicted, the quality has improved
considerably and the price has come down. That *does* open the door for
many more people to get satisfactory results, just as you are saying, and
it also makes service providers more comfortable with starting with a
machine-generated profile and then altering it as necessary.
The bottom line from these inquiries is that
machine-based ICC profiling is
the backbone of their colour management operations,
with occasional editing. If
you are trying to suggest that the occasional editing
invalidates the colour
management *claim*, then we will just have to agree to
disagree.
This puts you on the dangerous ground of arguing with
me about what I intended my own words to mean. So yes, we will have to
agree to disagree if you seriously think that this is what I was saying.
You should be able to satisfy yourself that this has never been my
position, however, by referring to two controversies which are well
documented by several threads in the list archives.
1) I have frequently pointed out how the SWOP v2
profile has the characteristic blue error found in many machine-generated
profiles. I also say that it could be easily edited to meet my objections.
2) In my 1998 review of Photoshop 5, and continuously
since, I have stated that without profile editing in Photoshop, the overall
concept would not catch on in the professional CMYK community. That
prediction has been borne out in spades--these printers, who apparently
have non-Photoshop profiling software, are the exception, not the rule.
Every time the subject is raised on this list, there is complete agreement
that more printers should behave as those mentioned here evidently do--as
well as complete agreement that the average printer wouldn't even know what
an ICC profile is, let alone how to work with it. The clear meaning of my
insistence on the ability to edit profiles is that there is a big source of
them that require editing, namely, those generated by machine.
I think we converge on the point that with the huge
reduction of cost that
has occurred, modern tools and techniques are vastly
opening the market of
private book publishing ventures on a global scale.
Yes, we agree, with the possible exception of
"vastly".
I believe that electronic devices and related software
are also making a
very substantial contribution to this outcome, to an
extent that may not have been so easily foreseen even ten years ago.
In 1994, I published the first edition of Professional
Photoshop. As a guide to professional color correction, its requirements
for accuracy were quite high. There were no proofs--it was with minor
exceptions all done on monitor approvals, several different monitors. I had
explained to the publisher that had no need for proofs to guarantee
accuracy because I had done this with so many different printers in so many
different countries that it was routine at this point. All that I needed
was a few examples of how the press had printed existing files, and I would
be able to derive the profile. This was arranged, and there was no
difficulty. As noted in my earlier post, I had used the same procedure at
many times during the late 1980s, and many firms were doing it in the early
1990s. So, the idea that it could not have been foreseen in 1994, let alone
1999, that users with limited calibration experience would be able to do it
in 2007 is a hard sell.
In 1994, it would have been considerably more difficult
to predict, although I did do so when others were pooh-poohing it, that a
photographer might be able to have all the *other* things needed to produce
this book by early in the 21st century. My recollection of 1994 pricing is
somewhat hazy so these numbers may be slightly off, but the general idea is
there. Today, a person with no hardware at all can purchase a camera and
computer capable of delivering high-quality files of, let us say, 25+
megabytes, for printing. The price tag would be $3,000 or so. In 1994,
counting inflation, it would have been a thousand times that. Storage space
and RAM cost *more* than a thousand times what it does today. But, assuming
that all this was in place, establishing a system that could create
contract proof-quality would only have cost 20-50 times as much as today.
Certainly, the image quality in that 1994 edition
leaves a lot to be desired in comparison to the 2006 edition. But it has
nothing to do with calibration or proofing--those were well under control
in 1994. It has nothing to do with computers that today do operations in
real time that took five minutes of waiting in 1994. It has nothing to do
with storage costing 75 cents a gig today and 75 dollars in 1994.
Better images make for better reproduction. Far better
to have a good file and limited knowledge of how it will be printed than a
bad one with the best color management in the world. I'm much better now
than I was in 1994. Improving one's skills is difficult. Calibration is
easy. If only it were capable of making poor files look good...
Dan Margulis
___________________________________________________________________________
Re: Color Management in Private Book Publishing
Posted by: Chris Murphy
Wed Jul 25, 2007 4:40 pm (PST)
On Jul 25, 2007, at 12:27 AM, dmargulisnj wrote:
The promise of the "universal language" was
that simply
embedding the tag in an RGB file would guarantee
consistent output
anywhere in the world.
Well that's just goofy. I don't know anyone who said
that, let alone some consistent application by experts to advocate such a
concept. No, the point of the embedded profile was to eliminate the
ambiguity of device-dependent numbers themselves. It does not guarantee,
and isn't implying a guarantee, that it would output correctly (either in
print or on just any display).
Dan, YOU are the one who has come up with this term and
YOU are the one who is defining it this way. You are the one rewriting
history, suggesting that not merely one person with this one little
embedded profile and magically that alone guarantees consistent output
anywhere in the world. It's absurd. So absurd my house plant across the
room read this email and said, "Wait, what? That makes no
sense!"
The promise of the "universal language" was
that case-by-case
discussions with printers would be eliminated. Because
that concept failed,
these two authors had to spend a good deal of time with
the printer's representative, just
as they would have 15 years ago.
OK no, you're wrong. Again. No one said the mere
embedding of profiles would eliminate discussions with printers. That
cannot happen in a vacuum. However, specifications such as PDF/X-3 and X-4
which do require the embedding of source profiles, as well as the
destination profile, do prescribe a workflow for blind handoffs of files
where such discussions, at least pertaining color are vastly reduced and in
some cases completely eliminated. Does that mean if you create PDF/X-3 and
send it to any printer this will happen? No, but you seem to infer that
because someone didn't make an obvious qualification that you're OK making
inferences from the lunatic fringe. You don't get to do that and sound
reasonable.
The promise of the "universal language" was,
as Photoshop
documentation of the time put it, an "all-RGB
workflow." It was theorized that CMYK was
poisonous, that photographers did not wish to know
anything about it, and
that this dirty business was the responsibility of the
printer, presumably at the
RIP stage. Because that concept failed, these two
authors supplied files in
CMYK, just as they would have 15 years ago.
Except that this is how fine art photographic printing
with 6+ channels of color is routinely done today, so wrong again. The
concept did not fail. Arguably it took a while to get all of the ducks in a
row so that this is possible. For printing to presses, there are a variety
of reasons why we are still stuck having to deal directly with CMYK. It's
absolutely demonstrated that dealing directly with actual channel data is
not a requirement for obtaining the finest quality output possible and
still having control. Direct access to channels is messy, it takes the
editing process out of the hands of the vast majority of people who have
enough skill to make visually based edits, but would hose a 4-color file
let alone a 6+ channel separation, just because those separations are
complex and editing them fraught with peril for those who aren't crystal
clear about what can fall apart.
Photographers don't really want to know anything about
CMYK. For inkjets, they largely don't have to. For presses, they do because
of rudimentary drivers and applications that do not make intelligent
decisions about separations based on image content, accounting for the
mechanical peculiarities of presses. But those who have accounted for these
variables, enter modern manufacturing capabilities and the corresponding
capacity for printing. And that includes not having to mess around directly
with CMYK.
The promise of the "universal language" was,
as pointed out in the article, that
all files would be subject to conversion by strangers.
Because that concept
failed, these two authors supplied files in press-ready
CMYK, where any
conversion would be an error, just as they would have
15 years ago.
The concept did not fail, it is being used in thousands
of print locations around the world successfully with completely blind
handoffs of PDF/X-1a and PDF/X-3. No on ever predicted that every single
printer everywhere in the world, by year XXXX, would all be using such
workflows.
No. By machine-made, I meant machine-made. No
human intervention, no
editing, no revision, no alteration, no way, no how.
This is just hogwash. The whole profiling process
involves human intervention. There are all kinds of rendering options in
the course of building a profile that will get you different results, and
those options do have default settings. It's not like you have a choice to
not use those options at all. Different people have different tolerances
and many people using very good measurement data will frequently use custom
separation parameters (for CMYK profiles) and make no further modifications
to the profile and are perfectly happy with the resulting separations.
Others do some level of profile tweaking here and there. People are not
doing major surgery on profiles when it comes to profile editing because
profiles simply can't withstand that kind of post-build edit.
While nobody AFAIK still endorses it, a common theory
in 1999 was that the machine was more sensitive than the human eye and that
any attempt to override its decisions
was self-defeating.
You've got to be kidding me. First of all your
terminology is wrong. "The machine" has a name. You could choose
to call it by its correct name so we know what contraption you're even
talking about, or you could continue to be vague.
Sensitive? Sensitive to what? There are consumer
spectrophotometers that are capable of sensing color differences with
certain colors (and saturation) with finer precision than human vision.
Very saturated colors for instance, we are not particularly sensitive to,
while measurement devices are. If you get to very expensive measurement
devices, they are extraordinarily sensitive compared to human vision
because they're built that way.
That would be like claiming that ICC profiles enable us
to use desktop
computers. Predictable color across a broad gamut of
devices was well
established in the professional community long before
1999.
So, what's your point again? There were no where near
the number of inkset, substrates or output devices the further back in time
you want to go. The problem was less of a problem the further back in time
you go. Today, some kind of color management and process control is a
prerequisite for output.
Chris Murphy
Color Remedies (TM)
New York, NY
___________________________________________________________________________
Re: Color Management in Private Book Publishing
Posted by: Chris Murphy
Wed Jul 25, 2007 9:43 pm (PST)
On Jul 25, 2007, at 11:25 AM, Chris Murphy wrote:
You are the one rewriting history,
suggesting that not merely one person with this one
little embedded
profile and magically that alone guarantees consistent
output
anywhere in the world.
A malformed sentence. I'll try again:
You [Dan] are the one rewriting history. You're
suggesting that not merely one person has supposedly come up with this
cockamamie idea of one little embedded profile and magically that alone
guarantees consistent color output anywhere in the world, but rather a
substantial number have done so. I certainly haven't heard of this,
probably because it's a cockamamie idea.
Chris Murphy
Color Remedies (TM)
New York, NY
___________________________________________________________________________
Re: Color Management in Private Book Publishing
Posted by: J Walton
Thu Jul 26, 2007 7:19 am (PST)
On 7/25/07, Chris Murphy wrote:
On Jul 25, 2007, at 11:25 AM, Chris Murphy wrote:
A malformed sentence. I'll try again:
You [Dan] are the one rewriting history. You're
suggesting that not
merely one person has supposedly come up with this
cockamamie idea of
one little embedded profile and magically that alone
guarantees
consistent color output anywhere in the world, but
rather a
substantial number have done so. I certainly haven't
heard of this,
probably because it's a cockamamie idea.
Still sounds weird. Here's my attempt:
You [Dan] are the one rewriting history. Not only are
you suggesting that ONE person has come up with this cockamamie idea of a
magical profile that guarantees consistent output anywhere in the world,
but that a SUBSTANTIAL number of people have done so. I, for one, am both
shocked and dismayed by this suggestion. You are a poopyhead.
Was the last part over the top?
<big grin>
--
J Walton
___________________________________________________________________________
Re: Color Management in Private Book Publishing
Posted by: "mcenigma"
Thu Jul 26, 2007 9:15 am (PST)
Well that's just goofy. I don't know anyone who said
that, let alone
some consistent application by experts to advocate such
a concept.
No, the point of the embedded profile was to eliminate
the ambiguity
Hello Chris:
Ok... I can tell you that I was on Vegas, San Fransisco
Photoshop world.. and I can think in 5 Instructors that they said exactly
that. I Can print exacly the same image in any place in the world.
so, if this is not the case well, we have people making
belive that.... If what not what they mean, sure that what many people end
up beliving at the end of a cople of the seccions.
thanks
Juan G. Aguilera Fernandez
___________________________________________________________________________
Re: Color Management in Private Book Publishing
Posted by: Chris Murphy
Thu Jul 26, 2007 2:29 pm (PST)
On Jul 26, 2007, at 11:58 AM, mcenigma wrote:
Hello Chris:
Ok... I can tell you that I was on Vegas, San Fransisco
Photoshop
world.. and I can think in 5 Instructors that they said
exacly that.
For one, Dan's 1999 claims predate Photoshopworld.
Second, there is a huge difference between an incomplete assertion, which
is what your anecdote may be an example of, and something that is
intentionally factually in error. Third, who are these five instructors?
I Can print exacly the same image in any place in the
world.
Fourth, did you or anyone else ask them to qualify
their statement? If not, why not?
so, if this is not the case well, we have people making
belive
that.... If what not what they mean, sure that what
many people end up
beliving at the end of a cople of the seccions.
I know Photoshopworld instructors personally. I can't
imagine any of them, off the top of my head, saying explicitly that all you
need to do to get correct color at output time is to embed a profile; or
that embedding a profile alone ensures correct output. It is vastly, vastly
more likely they simply are assuming that an appropriate output device
profile is being used for conversion, because to them it's obvious it would
need to be done.
You have to differentiate between someone being
misleading or vague and someone innocently lacking thoroughness in their
explanations. Baring a transcript or some evidence to the contrary, I would
assume the latter but if i knew who the instructors were, I would ask them
to qualify the statement.
And speaking of qualifying statements, I'd like to know
what equipment in 1988, let alone 1981 had such good monitor calibration
that hard proofs could be eliminated.
Chris Murphy
Color Remedies (TM)
New York, NY
___________________________________________________________________________
Re: Color Management in Private Book Publishing
Posted by: Dan Margulis
Fri Jul 27, 2007 7:41 am (PST)
Chris Murphy writes,
Well that's just goofy. I don't know anyone who said
that, let alone
some consistent application by experts to advocate such
a concept.
No, the point of the embedded profile was to eliminate
the ambiguity
of device-dependent numbers themselves. It does not
guarantee, and
isn't implying a guarantee, that it would output
correctly (either in
print or on just any display).
"Photoshop 5.0 offers a very powerful color
architecture, but with this power comes responsibility. To get optimal
results, you'll need to choose an appropriate RGB working space, and you
may need to experiment to find the settings that are ideal for your work.
You'll be glad that you did, though--investing a little time and effort in
this crucial area will ensure that your images look beautiful."
You don't know anybody who said that?
Except that this is how fine art photographic printing
with 6+
channels of color is routinely done today, so wrong
again. The
concept did not fail. Arguably it took a while to get
all of the
ducks in a row so that this is possible. For printing
to presses,
there are a variety of reasons why we are still stuck
having to deal
directly with CMYK.
Setting aside the obvious, that a skilled user who had
direct access to the six channels could get better results than one
restricted to RGB input, this point is not relevant to the thread, which
began with a suggestion that my article was incorrect because of the
experiences of two particular individuals in preparing their work for
press. My conclusion from reading the OP was:
1) There was a dialog between the authors and the
printers' representatives, just as there would have been in 1992, which
resulted in the handover of a suggested separation setting, just as might
have been done in 1992.
2) The authors eventually handed over CMYK files, just
as they would have done in 1992.
3) The CMYK files were not intended for conversion.
There were intended to be output as is, numbers and not appearance being
the criterion, just as would have been the case in 1992.
4) The authors were satisfied that the reproduction was
in line with expectations, just as would have been the case in 1992.
Therefore, the influence of the things being trumpeted
by your friends in 1999 was nil. Now as for the other irrelevancies you
brought up about how it really works in practice now, I would refer you to
the following quote from the 1999 article, which remains as sadly accurate
today as then:
"In retrospect, the articles trumpeting the
inevitability of this come together as a kind of poetry, elegant in its
cadence as much as in its annual repetition.
We've finally turned the corner,
Just a few more pieces must fall into place,
Ev'ry vendor will adopt it soon,
All we need do is educate users,
It really works now; next year for sure!"
Photographers don't really want to know anything about
CMYK. For
inkjets, they largely don't have to. For presses, they
do because of
rudimentary drivers and applications that do not make
intelligent
decisions about separations based on image content,
accounting for
the mechanical peculiarities of presses. But those who
have accounted
for these variables, enter modern manufacturing
capabilities and the
corresponding capacity for printing. And that includes
not having to
mess around directly with CMYK.
A person who desires quality presswork without wanting
to know anything about CMYK is like someone who aspirees to be a master
chef but doesn't want to know anything about the kitchen.
Some stereotype photographers as delicate, sensitive
folk, with a mentality too limited to comprehend such concepts as channel
curves or grafting a black channel onto a basically RGB structure. Besides,
black ink is dirty. Get it on your clothes or in your hair and it's hard to
get it out.
I have a great idea to keep any such photographers (if
they exist) out of the CMYK thicket where they don't belong. Why don't we
tell them that all they need is just a little time and effort to pick the
right RGB workspace, and it will ensure beautiful color?
Dan Margulis
___________________________________________________________________________
Re: Color Management in Private Book Publishing
Posted by: Chris Murphy
Sun Jul 29, 2007 4:22 pm (PST)
On Jul 27, 2007, at 8:17 AM, DMargulis wrote:
"Photoshop 5.0 offers a very powerful color
architecture, but with this power
comes responsibility. To get optimal results, you'll
need to choose an
appropriate RGB working space, and you may need to
experiment to find the settings
that are ideal for your work. You'll be glad that you
did, though--investing a
little time and effort in this crucial area will ensure
that your images look beautiful."
You don't know anybody who said that?
Nope. But this statement is a bird's eye, pie in the
sky context. There is no workflow prescription here, it doesn't even say
anything about profile embedding.
Setting aside the obvious, that a skilled user who had
direct access to the
six channels could get better results than one
restricted to RGB
input, this point is not relevant to the thread,
It's not obvious. It's an unsupportable statement. I
note that this access is available to 3rd party RIP vendors and yet they
consistently do not provide direct access to those channels outside
linearization and calibration functions. There is no market for fine art
photographers directly manipulating 6+ channels. And that's because the
conversions are actually very good and they are getting better.
Direct access to channels for an inkjet printer is
simply perilous and is astronomically more complex with each added channel.
The idea that photographers would actually want this is nonsense. They are
asking for a lot of things, but this isn't one of them.
1) There was a dialog between the authors and the
printers'
representatives, just as there would have been in 1992,
which resulted in the
handover of a suggested separation setting, just as
might have been done in 1992.
2) The authors eventually handed over CMYK files, just
as they
would have done in 1992.
3) The CMYK files were not intended for conversion.
There were intended to be
output as is, numbers and not appearance being the
criterion, just
as would have been the case in 1992.
4) The authors were satisfied that the reproduction was
in line with
expectations, just as would have been the case in 1992.
You're selecting very general things that are similar
between now and 1992 and extrapolating well beyond that with conclusions
that are not supportable by the facts at all.
Therefore, the influence of the things being trumpeted
by your friends in
1999 was nil. Now as for the other irrelevancies you
brought up
about how it really works in practice now,
PDF/X-3 isn't an irrelevancy. It exactly prescribes the
kind of workflow you say is a concept that has failed. Obviously it hasn't,
it's been turned into an ISO standard workflow that is actually being used
successfully.
A person who desires quality presswork without wanting
to know anything about
CMYK is like someone who aspirees to be a master chef
but doesn't
want to know anything about the kitchen.
The analogy doesn't work. CMYK is not the kitchen,
compared to RGB which is then what? CMYK is a gas cook top and RGB is
induction. Same precise control over heat, and instant response.
Chris Murphy
Color Remedies (TM)
New York, NY
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