Dan Margulis Applied Color Theory
Best Practice for RGB Stock Images
From: James Stuart Johnson
Date: Thu, Jan 23, 2003 3:18 pm
Subject: Best practice for RGB stock images?
Hi, all
I have been lurking here for ages. I finally have a
quick question.
I am working on a project-involving image for sale as
stock, i.e. Photos and hand generated Textures and Illustrations. I wish to
make them available for the widest possible usage while keeping them
accessible to software without profiling. I intend to use RGB TIFFs and
those using Photoshop or profile aware software I intend to embed a
profile, but which provides the possible range in RGB?
What I was able to gather so far form books and
manuals: Wide RGB looks like the way to go, I also noticed Pro Photo RGB I
have no idea of it's intended target.
Is there a good way of comparing profiles or website
comparing various spaces and recommending best practices? I would like some
kind of chart or histogram.
Basically is Wide RGB the best option or should I look
at other profiles?
Thanks,
James Stuart Johnson
J. Stuart J. Production Art & Imaging
________________________________________________________________________
From: Stephen Marsh
Date: Thu, Jan. 23, 2003 7:38 pm
Subject: Re: Best practice for RGB stock images?
James writes:
I have been lurking here for ages. I finally have a
quick question.
I doubt the thread answering the question will be
short or quick though. <g>
I am working on a project-involving image for sale as
stock, i.e.
Photos and hand generated Textures and Illustrations.
I wish to make
them available for the widest possible usage while
keeping them
accessible to software without profiling. I intend to
use RGB TIFFs
and those using Photoshop or profile aware software I
intend to embed
a profile, but which provides the possible range in
RGB?
With the above criteria, it would seem like ColorMatch
or Apple RGB for Mac clients and sRGB for PC clients. That is if you want a
problem free image for non ICC savvy users.
If you care more about the gamut and the profile -
then Adobe RGB 1998 would probably be the widest space I would use for 8
bpc RGB data. Just beware that non ICC savvy people or those who do not use
CM and A98 will often get the wrong result from the space (which is not
like a monitor or their default WS).
Do you know your client base, what they do and how
they do it?
Have you considered just one profile on the CD that
points to all images, or is tagging each one acceptable (for most RGB
profiles this should not add that much to the file size).
Are you considering value added metadata such as thumb
icons, previews, IPTC keywords etc (again considering file size additions
to the entire archive if this an issue. There was an old thread about
tagging 30,000 images with the same profile, but it escapes me).
What I was able to gather so far form books and
manuals: Wide RGB
looks like the way to go, I also noticed Pro Photo RGB
I have no idea
of it's intended target.
Well, it depends on where you read your stuff.
<g> There is the theory and the actual application of the theory -
often the two are not the same.
Is there a good way of comparing profiles or website
comparing
various spaces and recommending best practices? I
would like some
kind of chart or histogram.
The histogram would not have much meaning without
understanding the source image and the transforms.
Basically is Wide RGB the best option or should I look
at other
profiles?
Try these links, similar topics are mentioned and it
should give you some more defined points to consider and then you can ask
more targeted questions.
http:
//www.ledet.com/margulis/ACT_postings/ProfilingandProofing/ACT-I-
Switched.htm
http:
//www.ledet.com/margulis/ACT_postings/ProfilingandProofing/ACT-
profiles-who-what.htm
http:
//www.ledet.com/margulis/ACT_postings/ProfilingandProofing/ACT-
sRGB-vs-Adobe.htm
http://www.brucelindbloom.com/WorkingSpaceInfo.html
http://www.creativepro.com/story/feature/8582.html
http://www.creativepro.com/story/feature/6541.html
Hope this helps,
Stephen Marsh.
________________________________________________________________________
From: Terry Wyse
Date: Thu, Jan23, 2003 9:16 pm
Subject: Re: [colortheory] Best practice for RGB stock
images?
OK, I'll bite! :-)
I would have to say that Wide Gamut RGB and/or Pro
Photo RGB would probably hose the images for 95% or your
"audience". For those who treat the image correctly (preserve the
profile), both of those spaces are so "far out" that I consider
them of little use for general editing on a monitor (you won't see what
you're doing unless you scruntch it done to something reasonable like A98,
Colormatch or sRGB). I won't even say the "16-bit" word. ;-)
I'd probably go with Adobe98 but as Steve mentioned,
ColorMatchRGB and sRGB are not unreasonable choices for a non-ICC audience.
Maybe offer Mac/PC images tagged with these respective profiles. If the
user recognizes the profile, fine, if not, they're probably still going to
be OK.
I'd consider all the big, wide and loud spaces ( you
know who you are!) useful only as an archiving space from a high-end
scanner or digital camera capture where you need to store all the available
color for eons to come in hopes that the Ultra-Wide-Super-Chroma
offset/inkjet/photographic output device gets invented. And hope that your
image archive hasn't devolved into bits of noise on whatever medium you
stored it on.
Or I could be wrong.
Terry
--
__________________________________
WyseConsul
Color Management Consulting
v 704.843.0858
__________________________________
________________________________________________________________________
Date: Thu, 30 Jan 2003 20:14:14 -0500
From: Deb Koons
Subject: RE: Best practice for RGB stock images?
Hi James,
You can find out more info about Kodak's ProPhotoRGB
working-color-space at Kodak's ColorFlow website:
http://www.kodak.com/go/colorflow/
There are a couple of whitepapers there, and a
download of the actual profile.
I also found good info about color spaces in my copy
of "Real World Photoshop 7" and I suspect there is a lot of
discussion of this subject in the new "Real World Color
Management" (mine is on order).
HTH, Deb Koons
____________________________________________________________________________
Date: Sat, 1 Feb 2003 19:54:08 -0500
From: John Castronovo
Subject: Re: Best practice for RGB stock images?
ProPhotoRGB is intended to be a retouching space and a
speculative one at that as it allows one to describe colors beyond
theoretical limits. Some software can interpret these 'colors' as black! I
certainly wouldn't suggest using it to share files with anyone let alone
someone who might ignore the embedded profiles.
For the maximum compatibility, convert to sRGB after
doing your edits in a larger space. The result will look and print pretty
well on just about anyone's equipment even if they're not icc aware,
however, sRGB is certainly more gamut limited than some would like for very
saturated colors. In this regard, you're doomed either way.
Have a look at http:
//www.hutchcolor.com/Spreadsheets_to_go/RGB_coords.xls
if you'd like to compare these spaces with one
another.
john castronovo
____________________________________________________________________________
Date: Wed, 5 Feb 2003 15:36:40 -0700
From: Chris Murphy
Subject: Re: Best practice for RGB stock images?
On Saturday, February 1, 2003, at 05:54 ÊPM, john c.
wrote:
For the maximum compatibility, convert to sRGB after
doing your edits in a
larger space. The result will look and print pretty
well on just about
anyone's equipment even if they're not icc aware,
however, sRGB is certainly
more gamut limited than some would like for very
saturated colors. In this
regard, you're doomed either way.
I would not recommend converting images of any
importance to sRGB without consideration for where it will end up. If it's
likely it will be viewed on-screen or printed to an inkjet printer *on
Windows* this is not unreasonable. It's unfortunate, but that's another
discussion. For inkjet destinations on Mac OS, a gamma 1.8 space is still
assumed as source for many printer drivers, including all of Epson's that
I've seen.
If you have no choice but to go for "one size
fits all" then expect those kind of results as well.
Chris Murphy
Color Remedies (TM)
www.colorremedies.com/realworldcolor
____________________________________________________________________________
Date: Sat, 8 Feb 2003 18:59:51 -0500
From: John Castronovo
Subject: Re: Best practice for RGB stock images?
From: "Chris Murphy"
I would not recommend converting images of any
importance to sRGB
without consideration for where it will end up. If
it's likely it will
be viewed on-screen or printed to an inkjet printer
*on Windows* this
is not unreasonable. It's unfortunate, but that's
another discussion.
For inkjet destinations on Mac OS, a gamma 1.8 space
is still assumed
as source for many printer drivers, including all of
Epson's that I've
seen.
Agreed. I'm no fan of sRGB, but if one had to choose
just one space for an image to look best for most people who aren't icc
aware, it would have to be that. It's not good, just safe. BTW, which Mac
profile do you think is most common or safest? AppleRGB, Colormatch?
john castronovo
____________________________________________________________________________
Date: Sat, 8 Feb 2003 18:12:31 -0700
From: Chris Murphy
Subject: Re: Best practice for RGB stock images?
On Saturday, February 8, 2003, at 04:59 PM, john c.
wrote:
Agreed. I'm no fan of sRGB, but if one had to choose
just one space for an
image to look best for most people who aren't icc
aware, it would have to be
that. It's not good, just safe.
You still need to ask the question about the target
market. There are people who specifically target Mac users, and they are
absolutely in a good position to target ColorMatch RGB and not sRGB. If
your target is unknown, and the color sophistication is presumed to be
better on a Macintosh, then again it's not unreasonable to target
ColorMatch RGB. If your target is unknown, and you want the best possible
result for the largest market, then yes you would target sRGB because there
are a lot of Windows users on the planet. What to pick depends on the
situation - on the target market.
BTW, which Mac profile do you think is most
common or safest? AppleRGB, Colormatch?
If you or your customers have an Apple 13"
display, then Apple RGB is a reasonable choice. Otherwise, ColorMatch RGB
is the better choice.
I'm actually curious if sRGB actually still reflects
the behavior of the average CRT display still. And what of higher qualify
CRTs? What is the deviation? And also, what about the average LCD compared
to sRGB. And still further what about high quality LCDs? I have no data to
back up this supposition, but I wonder if sRGB is about to become
antiquated.
Along the lines of antiquity, I feel like the legacy
gamma of 1.8 on the Macintosh should be abandoned. The original reason we
have it is no longer applicable, and it just makes things a pain in the ass
for everyone. I feel it hurts us a lot more than it helps. It's a pain to
web developers. It's a pain to the online experience of Mac users. It's
also possibly a pain to print driver vendors, and display adapter vendors.
Chris Murphy
Color Remedies (TM)
www.colorremedies.com/realworldcolor
____________________________________________________________________________
Date: Sun, 09 Feb 2003 03:00:26 -0000
From: "Stephen Marsh
Subject: Re: Best practice for RGB stock images?
--- "john c." wrote:
Agreed. I'm no fan of sRGB, but if one had to choose
just one space for an
image to look best for most people who aren't icc
aware, it would have to be
that. It's not good, just safe. BTW, which Mac profile
do you think is most
common or safest? AppleRGB, Colormatch?
John, if we are talking about non ICC savvy users -
then it makes little difference.
Test it yourself. Assign ColorMatch RGB to a Apple RGB
file, or vice versa. Minor saturation loss/gain in some cases - much more
minor than possible monitor differences between users. I would just run
with CM RGB.
Not the same sort of thing as getting sRGB and A98
mixed up.
Stephen Marsh.
____________________________________________________________________________
Date: Sun, 9 Feb 2003 12:01:21 -0000
From: "Bob Frost"
Subject: Re: Best practice for RGB stock images?
Chris,
The new version, to complement the existing sRGB, is
already on its way -sRGB64.
www.microsoft.com/hwdev/tech/color/sRGB64.asp
Bob Frost.
____________________________________________________________________________
Date: Sun, 9 Feb 2003 08:30:10 -0600
From: "John"
Subject: Re: Best practice for RGB stock images?
Good Morning,
I wish someone could answer this sRGB question for me.
I use one of the largest color labs in the USA, they
were one of the first if not the first pro lab to offer digital imaging and
they have always used sRGB. I have asked people in their customer service
departments and they don't know either, but will try to get back to me.
They are mainly a "portrait" lab, but I'm
sure there is some commercial work, I use a local lab for my commercial
assignments.
Best,
John Douglas
____________________________________________________________________________
Date: Sun, 9 Feb 2003 11:02:25 -0500
From: "john c."
Subject: Re: Best practice for RGB stock images?
Along the lines of antiquity, I feel like the legacy
gamma of 1.8 on
the Macintosh should be abandoned. The original reason
we have it is no
longer applicable, and it just makes things a pain in
the ass for
everyone. I feel it hurts us a lot more than it helps.
It's a pain to
web developers. It's a pain to the online experience
of Mac users. It's
also possibly a pain to print driver vendors, and
display adapter
vendors.
Chris,
I agree that it would be good for Macs to abandon the
1.8 standard. It makes it really tough for everyone. Of course, the real
problem is that people still refuse to embed and use profiles.
If we only knew that an image was prepared for viewing
with one profile or another, none of this would be a problem. Yet, people
who should know better like printers and pre-press folks still yell at me
when I ask them for a source profile. I get responses like, "What's a
profile" or "How come YOU need a profile and I don't?" Who
has the power to change an industry so rigidly stuck in stupidity?
john castronovo
____________________________________________________________________________
Date: Sun, 9 Feb 2003 13:11:59 -0700
From: Chris Murphy
Subject: Re: Best practice for RGB stock images?
On Sunday, February 9, 2003, at 05:01 AM, Bob
Frost wrote:
The new version, to complement the existing sRGB, is
already on its
way -- sRGB64.
From what I can tell, this is more of a
competitor to Adobe RGB (1998) (in concept), than it is an update to sRGB.
sRGB was based on average CRT behavior, with presumably some modifications
to make it gray balanced and behave well. What I'm looking for is an
updated profile that describes the average display. If that's still sRGB,
fine. I don't find yet another RGB space for editing images to be very
compelling by itself. But if Microsoft allows a mechanism to use sRGB64
instead of sRGB for prosumers, I can see why it's being suggested. However,
I think it would be easier to create a UI for the end user to select their
own assumed space on a system wide basis, instead of creating yet another
color space for us to debate about. And 64-bits? What's that mean? How is
64-bits total divisible by three channels? And what CMMs are doing
computations with more than 16-bits? I know of only Adobe ACE (which uses
20-bits per channel).
Chris Murphy
Color Remedies (TM)
www.colorremedies.com/realworldcolor
____________________________________________________________________________
Date: Sun, 9 Feb 2003 13:13:37 -0700
From: Chris Murphy
Subject: Re: Best practice for RGB stock images?
On Sunday, February 9, 2003, at 07:30 AM, John
wrote:
I use one of the largest color labs in the USA, they
were one of the first if
not the first pro lab to offer digital imaging and
they have always used sRGB.
I have asked people in their customer service
departments and they don't know
either, but will try to get back to me.
So what's the question? :) Why does this lab use sRGB?
I have no idea. You'd have to ask them. And there is a really good chance
they aren't going to have a compelling answer.
Chris Murphy
Color Remedies (TM)
www.colorremedies.com/realworldcolor
____________________________________________________________________________
Date: Sun, 9 Feb 2003 13:30:43 -0700
From: Chris Murphy
Subject: Re: Best practice for RGB stock images?
On Sunday, February 9, 2003, at 09:02 AM, john
c. wrote:
I agree that it would be good for Macs to abandon the
1.8 standard. It makes
it really tough for everyone. Of course, the real
problem is that people
still refuse to embed and use profiles.
Not everything needs them. For example, web content is
already based on sRGB for all practical purposes. And since most people
using a computer are viewing web pages and email (with increasing amounts
of HTML content), it makes sense to me to dump the legacy 1.8 gamma in
favor of the more common media. People who really think they need gamma 1.8
for some reason can use Display Calibrator or buy a 3rd party instrument
and calibrate to 1.8. I use 2.2, and incidentally all three authors of Real
World Color Management use and recommend 2.2.
We should be in a position to make reasonable
assumptions about average display behavior, be it a CRT, LCD, movies from
digital camcorders (which don't use profiles), and other media sources. I
just think it would be easier if the legacy 1.8 gamma wasn't in the way.
The reason for its existence is no longer in existence (unless you have an
original Apple Laserwriter in production use).
If we only knew that an image was prepared for viewing
with one profile or
another, none of this would be a problem. Yet, people
who should know better
like printers and pre-press folks still yell at me
when I ask them for a
source profile. I get responses like, "What's a
profile" or "How come YOU
need a profile and I don't?" Who has the power to
change an industry so
rigidly stuck in stupidity?
They probably don't need a profile because they're so
used to their closed-loop system that the profile is actually in their
heads. They just don't see it that way. You need that mental profile put
into a physical file - an ICC profile - because you don't work with their
equipment day in and day out.
Years after saying it, I'm still of the opinion that
printers' responsibility is to:
1. Provide consistent and stable press conditions; and
2. The press behavior should be based on a standard
(GRACoL, SWOP, ISO 12647, whatever) *OR*
3. They need to supply a profile for their unique
press condition *OR*
4. They need to accept jobs with tagged images, honor
the tag, and separate the job properly
And print buyers' responsibility is to:
1. Prepare properly separated files (per printer's
requirements, either standardized or based on their profile) *OR*
2. Supply jobs with properly tagged files.
On top of that - both parties need to agree on a
contract proofing system and produce contract proofs before going to press.
That is the last line of "defense" to protect both parties and
finalize expectations.
It's pretty simple if everyone agrees on what their
role is going to be. Clearly defined roles sets up acceptable expectations
on both sides, and makes it clear which party isn't holding up their end of
the bargain. Most arrangements seem to deal with these issues after a
problem has already occurred.
Chris Murphy
Color Remedies (TM)
www.colorremedies.com/realworldcolor
____________________________________________________________________________
Date: Sun, 9 Feb 2003 23:23:08 -0500
From: John Castronovo
Subject: Re: Best practice for RGB stock images?
From: "Chris Murphy"
So what's the question? :) Why does this lab use sRGB?
I have no idea.
You'd have to ask them. And there is a really good
chance they aren't
going to have a compelling answer.
My guess is that they installed PhotoShop and never
knew enough to change
the default settings. <g>
john castronovo
____________________________________________________________________________
From: Ron Kelly
Date: Mon, Feb 10, 2003 12:50 am
Subject: Re: [colortheory] Best practice for RGB stock
images?
Chris Murphy wrote:
I just think it
would be easier if the legacy 1.8 gamma wasn't in the
way. The reason
for its existence is no longer in existence (unless
you have an
original Apple Laserwriter in production use).
Chris:
What is the reason for choosing one gamma over
another?
Is it anything more than simply a convention? Are you
asking that everyone switch to a common standard for convenience, or is
there more to it than that?
Ron Kelly
____________________________________________________________________________
From: Stephen Ray
Date: Mon, Feb 10, 2003 2:41 am
Subject: Re: [colortheory] Best practice for RGB stock
images?
On Sunday, February 9, 2003, at 07:30 AM, John wrote:
I use one of the largest color labs in the USA, they
were one of the first if
not the first pro lab to offer digital imaging and
they have always used sRGB.
I have asked people in their customer service
departments and they don't know
either, but will try to get back to me.
I can offer an educated guess at this one.
Probably because sRGB is
1.) ubiquitous and
2.) it happens to (somewhat) represent photographic
paper from scanned photos, and
3.) sRGB can often make scanned film's flesh tones
more realistic than if the film were scanned using a larger gamut color
space.
I'm currently imaging a client's photo tests comparing
Adobe 98 and sRGB and, at first blush, the sRGB is clearly the better photo
rendition in regards to saturation and neutrality, as is usually the case.
Stephen Ray
____________________________________________________________________________
From: Chris Murphy
Date: Mon, Feb 10, 2003 12:29 pm
Subject: Re: [colortheory] Best practice for RGB stock
images?
sRGB doesn't inherently represent photographic paper
from scanned photos. That is occurs is probably because the scanner is
specifically targeting sRGB behavior. This would also explain the results
you get in #3 above. If the scanner targets sRGB, then of course sRGB
should be the assigned profile and that will make the image look correct,
Adobe RGB won't. If the scanner is placed into a raw scanning mode,
profiled, then scan an image, use the profile to convert the image from raw
scanner RGB to Adobe RGB, I think you will see noticeably better results.
Chris Murphy
Color Remedies (TM)
www.colorremedies.com/realworldcolor
____________________________________________________________________________
From: Chris Murphy
Date: Mon, Feb 10, 2003 12:25 pm
Subject: Re: [colortheory] Best practice for RGB stock
images?
On Sunday, February 9, 2003, at 10:50 PM, Ron Kelly
wrote:
What is the reason for choosing one gamma over
another?
Gamma is by far not the biggest issue or debate we
have in color management, or operating systems. BUT, if it's the topic of
the hour, there are a number of reasons why I don't think gamma 1.8 is
appropriate anymore:
a.) Monitors have a natural gamma of around 2.2 to
2.4. Calibration results will be better (reduced potential for calibration
induced posterization/banding) the less we change the monitor.
b.) Gamma 2.2 is more perceptually uniform. It's not
exactly the same thing as what we get with LAB, which has something more
complex than just a gamma curve, but a gamma just over 2.3 is a close
approximation.
c.) The reason why we used gamma 1.8 to begin with, to
simulate the mid-tone gain of a particular output device, no longer exists
and is no longer needed. Using gamma was a form of hardware grayscale
management. This is now performed by the CMS using profiles and it's not
something that can be turned off. So gamma 1.8 is simply antiquated.
d.) Most of the things consumers do on a computer is
browse the web, email, use a digital camera, and maybe print some images
every now and then. All of these things would benefit if the platforms
didn't have different gammas. That's the main reason for color matching
problems - gamma discrepencies. The phosphors in CRTs aren't drastically
different, but their tone reproduction can be.
The bottom line is that more people are aided by the
dumping of the legacy 1.8 gamma than are hurt by it.
Now as for the gamma of an editing space - that's a
different debate. I still think a gamma 2.2 space is better, especially if
we're working in an 8-bits/channel space. But some have claimed better
reversibility (going into and out of a space) with a gamma 1.8 based color
space. I haven't seen compelling real world examples of this yet, however.
Chris Murphy
Color Remedies (TM)
www.colorremedies.com/realworldcolor
____________________________________________________________________________
From: Jono Moore
Date: Date: Mon, Feb 10, 2003 8:16 pm
Subject: Re: [colortheory] Best practice for RGB stock
images?
on 9.2.03 8:02 AM, john c. at wrote:
If we only knew that an image was prepared for viewing
with one profile or
another, none of this would be a problem. Yet, people
who should know better
like printers and pre-press folks still yell at me
when I ask them for a
source profile. I get responses like, "What's a
profile" or "How come YOU
need a profile and I don't?" Who has the power to
change an industry so
rigidly stuck in stupidity?
How about "rigidly stuck with what works"?
If you are going to be happy with "good
enough" colour, sure. If you really want your pictures to look their
best are you going to want to rely on profiles?
Not to mention all the variables involved in profiling
a print shop...
I mean, isn't this what Dan's book is all about?
We just produced an art book for our local museum,
which went to a very high-end shop for printing. They're all over
profiling, direct to plate, digital proofing, etc. The proofs did not look
like the printed piece, thankfully, but we were trying to make colour
decisions based on those proofs. The project was behind schedule so we just
had to cross our fingers and hope for the best. Luckily it turned out the
way it was supposed to, not how the proofs looked.
Part of the problem as I see it:
Say we have a profiled shop. You give us a bunch of
RGB files with profiles attached. We print the job and there are complaints
about the colour. Part of _my_ problem with this is that I can not go back
and check the colour of the picture (vs. what came out on the press/proof)
because it's in RGB! If it's in CMYK I can take the eye dropper to it and
say, beyond a reasonable doubt, if the colour is accurate or not. If this
was to happen, and everyone says they are profiled properly, who is to
blame?
--
Jono Moore
udoprinting.com
____________________________________________________________________________
From: "Stephen Marsh
Date: Date: Mon, Feb 10, 2003 11:01 pm
Subject: Re: Best practice for RGB stock images?
Chris Murphy wrote:
b.) Gamma 2.2 is more perceptually uniform. It's not
exactly the same
thing as what we get with LAB, which has something
more complex than
just a gamma curve, but a gamma just over 2.3 is a
close approximation.
Ah, I have not heard of this before Chris - not just a
simple gamma curve? Do you mean that there are more than one control point
on the curve in addition to the midtone, which affect the slope in other
areas? A bit like that other version of plain old sRGB that has a weird
gamma curve that is not standard? And now I hear of sRGB64, which is bound
to confuse things for some users or manufacturers by including sRGB in the
file name when it is apparently not like plain vanilla sRGB...why not
MSHP64 RGB?. Or is that HPMS64 RGB? <g>
Is there a definitive published source ANYWHERE on
this? 2.5 or 3 is the closest thing I have read in print, and quick tests
seem to back this up whe examing USM, but I have not compared luminance
levels lost in various RGB gammas to LAB to try to see which RGB looses the
same amount of unique levels (as a rough indication of the approx gamma,
not that I know if this is an accurate way to establish gamma of L of LAB,
I am just running with what I think I know! <g>).
Now as for the gamma of an editing space - that's a
different debate. I
still think a gamma 2.2 space is better, especially if
we're working in
an 8-bits/channel space. But some have claimed better
reversibility
(going into and out of a space) with a gamma 1.8 based
color space. I
haven't seen compelling real world examples of this
yet, however.
Chris, you probably ignored the recent thread which
was about sharpening,
linear colour blending option and gaussian blurs in
gamma1 vs. gamma compensated spaces, due to your keyword filter excluding
the terms TIMO or AIM etc. <g>
At first blush it seems that 2.2 gamma RGB is the only
common one which stuffs up the colour of a large blur which averages two
unique unblurred colours. 1.8 RGB, LAB and CMYK do not desaturate, they
still keep some degree of colour, although the end hue does vary between
spaces. This was in reference to a section of Timos site that someone
recently asked about, he has a blue and red chessboard pattern gaussian
blur demo. I did not test higher than A98 which uses 2.2, perhaps I should
have (or tested other phosphor primaries at 2.2 gamma etc) - but I was just
attempting to add to the original question by saying that 1.8 gamma RGB,
LAB and CMYK edits should not be forgotten in the whole debate about the
relative merits of some specific edits in gamma1 or 2.2 spaces (I get the
feeling that for some there are no other spaces except 1 or 2.2 gamma RGB -
when for me serious editing is never that bland).
Stephen Marsh.
____________________________________________________________________________
From: Terry Wyse
Date: Date: Mon, Feb 10, 2003 10:43 pm
Subject: Re: [colortheory] Best practice for RGB stock
images?
on 2/10/03 8:16 PM, Jono Moore wrote:
How about "rigidly stuck with what works"?
If you are going to be happy with "good
enough" colour, sure. If you really
want your pictures to look their best are you going to
want to rely on
profiles?
I don't know what this comment has to do with
profiles. Profiles are a TOOL to help you achieve more predictable color,
nothing more, nothing less. I'd argue that using profiles will get you to
GOOD color quicker than almost anything else. It will always take a good
operator to get to GREAT color from that point.
Not to mention all the variables involved in profiling
a print shop...
Yes, that's the "problem" with profiles:
they actually make a prepress/print shop responsible for the color they
produce and "force" them to use some measure of process control.
Yes, that's a bad thing.
I mean, isn't this what Dan's book is all about?
Uh, no. Dan, in fact, uses profiles to his advantage
when called for and ignores profiles when he feels they get in his way. At
least that's my take.
We just produced an art book for our local museum,
which went to a very
high-end shop for printing. They're all over
profiling, direct to plate,
digital proofing, etc. The proofs did not look like
the printed piece,
thankfully, but we were trying to make colour
decisions based on those
proofs. The project was behind schedule so we just had
to cross our fingers
and hope for the best. Luckily it turned out the way
it was supposed to, not
how the proofs looked.
They had proofs that didn't reflect what they printed?
What does this have to do with profiles? If they we're using profiles in
proofing to simulate their press, they OBVIOUSLY had bad profiles or at the
very least had profiles that no longer represented what they are printing
today. Again, lack of process control could be the culprit assuming they
had accurate profiles at one time.
Say we have a profiled shop. You give us a bunch of
RGB files with profiles
attached. We print the job and there are complaints
about the colour. Part
of _my_ problem with this is that I can not go back
and check the colour of
the picture (vs. what came out on the press/proof)
because it's in RGB! If
it's in CMYK I can take the eye dropper to it and say,
beyond a reasonable
doubt, if the colour is accurate or not. If this was
to happen, and everyone
says they are profiled properly, who is to blame?
#1: Using profiles does NOT force one into an RGB
workflow.
#2: Let's see, you can put an eyedropper on any CMYK
value and KNOW if the color is accurate or not? And what if I told you
these CMYK values were going to a sheetfed offset press? A web press? How
about if it's going to be printed flexo? The final product is going to an
inkjet printer? Do these all mean the same thing to you as far as CMYK?
This whole notion that if you have RGB images you
CAN'T know what the color is vs. having CMYK images you can ALWAYS
accurately predict what the color is is simply nonsense.
Terry "rigidly stuck in ignorance" Wyse
--
__________________________________
WyseConsul
Color Management Consulting
v 704.843.0858
__________________________________
____________________________________________________________________________
From: J Walton
Date: Tue, Feb 11, 2003 12:37 am
Subject: Best RGB space for CMYK output
I know that this general issue has been discussed
before, but I haven't seen this specific question asked. If it has been,
you have my apologies.
I work for a prepress company which has moved to an
RGB workflow. We scan and retouch in DonRGB, but all of our output is CMYK.
We never have a use for RGB as a final product. I wonder if we've chosen
the wrong working space.
Question 1 - If you did not have to worry about RGB
output and could focus on making CMYK images look good, what RGB working
space would you use?
Question 2 - If you chose sRGB or Colormatch, how
would you avoid clipping on pure cyans and yellows?
Thanks,
J Walton
____________________________________________________________________________
From: "Stephen Marsh
Date: Tue, Feb 11, 2003 4:33 am
Subject: Re: Best RGB space for CMYK output
J Walton wrote:
I work for a prepress company which has moved to an
RGB workflow. We scan
and retouch in DonRGB, but all of our output is CMYK.
We never have a use
for RGB as a final product. I wonder if we've chosen
the wrong working
space.
You mean CMYK should have been chosen?
Question 1 - If you did not have to worry about RGB
output and could focus
on making CMYK images look good, what RGB working
space would you use?
Sounds like CMYK and not RGB?
Question 2 - If you chose sRGB or Colormatch, how
would you avoid clipping
on pure cyans and yellows?
Cyan would not be clipped, as it is possible to reach
100C in CMYK.
<g>
Sorry J - I could not resist.
There should be no reason why these issues could not
be addressed in post separation edits (or has everyone there forgotten how
to directly edit CMYK now that they use RGB?).
Unless you move to a wider gamut RGB space, there is
no way around the maximum cyan generation - but this may not always be
needed for all images, and if it is required and you do have to use a more
narrow RGB, then you will either have to introduce post sep edits or accept
the limitations of the chosen RGB space.
I have worked in RGB workflows for press (that always
sounds like an oxymoron to my ears <g>) - and I have worked in other
situations where RGB is alien and a rare site...or mixes of both. You
eventually adapt in either case.
Stephen Marsh
____________________________________________________________________________
From: Chris Murphy
Date: Tue, Feb 11, 2003 12:54 am
Subject: Re: [colortheory] Best practice for RGB stock
images?
On Monday, February 10, 2003, at 06:16 PM, Jono Moore
wrote:
If you are going to be happy with "good
enough" colour, sure. If you really
want your pictures to look their best are you going to
want to rely on
profiles?
If you change this to: "If you really want your
pictures to look their best, are you going to want to rely *only* on
profiles?" then my answer is "no." You can't automate all
aspects of getting the best possible color reproduction - yet. But as
written above, I'd disagree. Yes you must rely, to a fair degree, on
profiles. But not just any kind of profile - high quality production
profiles.
I mean, isn't this what Dan's book is all about?
Dan's book is about image enhancement. It's important
to realize the limitations of color management, not getting so totally
wrapped up in it that you spend all or most of your energy there instead of
on your images. At the same time, it's possible to spend all or most of
your energy on your images, and end up chasing your tail as you try to
output from device to device. What's necessary is to find the right
balance.
We just produced an art book for our local museum,
which went to a very
high-end shop for printing. They're all over
profiling, direct to
plate, digital proofing, etc. The proofs did not look
like the printed piece,
OK, I've cut the quote right there because a huge
contradiction has occurred. First, they can't be that high-end, let alone
all over profiling, if the proofs don't look like the printed piece.
PERIOD. That's a serious breach of what contract proofs are all about. No
one expects proofs to be identical to the printed piece, but they expect
them to be reasonably representative within limits agreed upon by customer
and printer in advance.
Say we have a profiled shop. You give us a bunch of
RGB files with profiles
attached. We print the job and there are complaints
about the colour.
Again - stop right there. You've left out the proof!
Who is suggesting that printers should receive RGB files, with (or without
profiles), and immediately print the job? You *PROOF* first and then you
get the complaint. You don't go to press and get a complaint. That's
seriously anachronistic! OK...continuing:
Part
of _my_ problem with this is that I can not go back
and check the colour of
the picture (vs. what came out on the press/proof)
because it's in RGB!
No offense, but that's not at all compelling. If you
don't want to accept RGB jobs that might be OK, as it depends on your
company's business model. I'd suggest that as time goes forward there is an
increasing likelihood you will need to have an effective means of dealing
with RGB jobs because they are increasingly common. Those who figure out
how to deal with them effectively will get those kinds of jobs, and make
money servicing those customers.
Regardless, you do need to give the customer a
mechanism by which their jobs can be properly separated. Who does the
separation is an important, but secondary consideration.
If you're going to accept RGB jobs, then you need to
have the right tools. Various prepress systems will accept RGB PostScript
or PDF jobs, convert the entire document using either embedded or assumed
profiles as sources, to a destination profile you specify and boom - it's a
CMYK job - and you can check CMYK values. That's the file that the proof is
produced from and plates are produced from for printing on press.
If you don't have such a system, you can take the
PostScript file from the page layout application (which converts the
document to CMYK at print time), make a PDF of it, and bring it into
Acrobat running Pitstop Pro and it will let you poke around with an
eyedropper tool on any object you want, and see its CMYK values.
If it's in CMYK I can take the eye dropper to it and
say, beyond a reasonable
doubt, if the colour is accurate or not. If this was
to happen, and everyone
says they are profiled properly, who is to blame?
These things should be dealt with at the proofing
stage. And it's not about blame. It's about a process. Who is responsible
for what? And determining if everyone did what they were supposed to. And
then proofing the job to make sure it looks the way it should.
If there are problems proofing, you troubleshoot it
with a similar mindset as you do font problems, or trapping problems.
Familiarity and experience with the process, and having the right tools to
aid in troubleshooting gives you the ability to find out where the problem
is, and what's going to be done to fix it.
Chris Murphy
Color Remedies (TM)
www.colorremedies.com/realworldcolor
____________________________________________________________________________
From: Chris Murphy
Date: TueÊFebÊ11,Ê2003 1:06 am
Subject: re: LAB's gamma curve
On Monday, February 10, 2003, at 09:01 PM, Stephen
Marsh wrote:
Ah, I have not heard of this before Chris - not just a
simple gamma
curve? Do you mean that there are more than one
control point on the
curve in addition to the midtone, which affect the
slope in other
areas?
Yes. I'll let Bruce Lindbloom answer this one in more
detail. All I know that a simple gamma curve doesn't describe L*, but is
closely approximated by a gamma curve just over 2.3. Bruce?
A bit like that other version of plain old sRGB that
has a
weird gamma curve that is not standard? And now I hear
of sRGB64,
which is bound to confuse things for some users or
manufacturers by
including sRGB in the file name when it is apparently
not like plain
vanilla sRGB...why not MSHP64 RGB?. Or is that HPMS64
RGB? <g>
sRGB is a familiar term. So it might be selected for
marketing reasons. I have no idea. I'm still not getting how it's 64-bit
based.
At first blush it seems that 2.2 gamma RGB is
the only common one
which stuffs up the colour of a large blur which
averages two unique
unblurred colours.
Blending is more colorimetrically accurate in gamma
1.0 spaces as far as I know. This is why Adobe stuck in that option in
Photoshop 6, with limitations: it doesn't affects all blends. I don't know
what the solution to the problem is ultimately, but what I can say is that
when it comes to editing spaces, there is still some room for debating
gamma 1.8 versus gamma 2.2. Why this isn't occurring in LAB, which has a
slightly higher gamma, I don't know either. Perhaps Bruce has an idea.
Chris Murphy
Color Remedies (TM)
www.colorremedies.com/realworldcolor
____________________________________________________________________________
Date: Tue, 11 Feb 2003 07:03:12 -0700
From: Andrew Rodney
Subject: Re: Best RGB space for CMYK output
on 2/10/03 10:37 PM, J Walton wrote:
I work for a prepress company which has moved to an
RGB workflow. We scan
and retouch in DonRGB, but all of our output is CMYK.
We never have a use
for RGB as a final product. I wonder if we've
chosen the wrong working
space.
Haven1t plotted it but I expect it1s a pretty large
space. I suspect it1s a lot larger than the display gamut which might be an
issue for you. Frankly, Adobe RGB 1998 sounds like it would work fine with
a CMYK only output workflow.
Question 1 - If you did not have to worry about RGB
output and could focus
on making CMYK images look good, what RGB working
space would you use?
Question 2 - If you chose sRGB or Colormatch, how
would you avoid clipping
on pure cyans and yellows?
It1s more likely you1re NOT clipping the colors in a
larger space because you were at least able to capture them. I1d stay away
from sRGB because it is certainly going to possibly have colors outside
(smaller in some cases) than 3CMYK gamut2 (notice the quote since that1s
saying a lot).
IF DonRGB is working for you, why mess with it?
Otherwise, Adobe RGB seems like a safe bet.
Andrew Rodney
____________________________________________________________________________
Date: Tue, 11 Feb 2003 09:42:52 -0500
From: Jim Rich
Subject: Re: Best practice for RGB stock images?
Jono wrote:
Say we have a profiled shop. You give us a bunch of
RGB files with profiles
attached. We print the job and there are complaints
about the colour. Part
of _my_ problem with this is that I can not go back
and check the colour of
the picture (vs. what came out on the press/proof)
because it's in RGB! If
it's in CMYK I can take the eye dropper to it and say,
beyond a reasonable
doubt, if the colour is accurate or not. If this was
to happen, and everyone
says they are profiled properly, who is to blame?
Jono,
I am not sure what your rant is here, but technically
speaking, why cant you go back and check the RGB file using the eyedropper
to check the CMYK values? The eyedroppers work in RGB so you can preview
the CMYK values as though the image was a CMYK file.
Profiles are just one part of the process that helps
businesses communicate color more efficiently. The process will work
without them it will just take longer to get it done. It sounds like want
is missing from your post is the part where you use common sense when
working with profiles and then some skill and to get the color correct.
Jim Rich
____________________________________________________________________________
Date: Tue, 11 Feb 2003 12:27:20 -0500
From: Terry Wyse
Subject: Re: Best RGB space for CMYK output
on 2/11/03 12:37 AM, J Walton wrote:
I work for a prepress company which has moved to an
RGB workflow. We scan
and retouch in DonRGB, but all of our output is CMYK.
We never have a use
for RGB as a final product. I wonder if we've
chosen the wrong working
space.
If you're coming off of a good drum scanner or
high-end flatbed, DonRGB or BestRGB are decent working spaces from which to
convert FROM your scanner profile. Whenever I setup a drum scanner, those
are my preferred spaces to convert to. BestRGB is preferred as it has a bit
more extension in the reds to accommodate Fuji transparence media. You can
go to Don's site (www.hutchcolor.com) to download BestRGB.
Question 1 - If you did not have to worry about RGB
output and could focus
on making CMYK images look good, what RGB working
space would you use?
Question 2 - If you chose sRGB or Colormatch, how
would you avoid clipping
on pure cyans and yellows?
If you've got some analysis tools (ICCToolBox or
ColorThink for example), you should be able to verify that your
"working space" is at least as large as your scanner profile.
Choose the smallest working space that still encompasses your scanner
profile's color gamut.
There's going to be a bazillion opinions on how to
answer your question(s) correctly and many of them will be
"correct" in their own way. Here's my two cents worth:
Personally, if I had a decent scanner, I'd want to
"keep" as much of the original scanner data as possible without
clipping or "throwing it away" by moving the data into a working
space that is too small. This means choosing the SMALLEST space that is
just LARGE enough to not clip any of the original scanner data. Since any
move (AFAIK) from a scanner/input space to a working space is going to be a
relative colorimetric conversion, it will CLIP any colors that our in the
scanner space but outside the working space. Once moving the image into
this "just right" working space, you then could consider this the
"RGB Master" or archive image.
In regards to moving from RGB to CMYK, you could then
make use of the various rendering intent choices (perceptual or relative
colorimetric w/ BPC on/off most likely) to CONTROL how the colors get
clipped or "scaled" into your CMYK space. You're going to
"lose" color data no matter what but I'd rather have a bit more
control of how that happens rather than simply throw it away up front when
moving from scanner space to working space where it WILL clip the data if
you've chosen a working space that is too small.
Again, careful analysis of your scanner profile(s)
compared to the various standard working spaces will give you the
information you need to make the correct choice.
Terry
__________________________________
WyseConsul
Color Management Consulting
v 704.843.0858
__________________________________
____________________________________________________________________________
Date: Tue, 11 Feb 2003 16:08:25 -0500
From: Terry Wyse
Subject: Re: Best RGB space for CMYK output
What I MEANT to simply say but didn't explain very
eloquently:
You DO NOT have control over the clipping of colors
when moving from a scanner input profile to a RGB working space profile.
There's no option for rendering intent. All conversions from scanner to
working space RGB will be relative colorimetric. Thus, you'd want to use
the smallest working space that encompasses the scanner profile.
You DO have control when performing a RGB-to-CMYK
conversion over HOW the out of gamut colors get handled.
SO....start with a RGB working space that
doesn't throw away colors right from the start and use a combination of
rendering intent and your skill as an operator to decide WHICH color(s) get
clipped in the final CMYK conversion.
Terry
____________________________________________________________________________
Date: Tue, 11 Feb 2003 13:31:19 -0700
From: Chris Murphy
Subject: Fwd: LAB's gamma curve
Here we go:
> The equation for converting luminance, Y, into L*
is shown here:
> <http:
//www.brucelindbloom.com/Eqn_XYZ_to_Lab.html>
>
> The equation for converting L* to Y is shown here:
> <http:
//www.brucelindbloom.com/Eqn_Lab_to_XYZ.html>
>
> An interactive companding calculator for viewing
gamma, L*, density, > etc.
> may be found here:
> <http:
//www.brucelindbloom.com/CompandCalculator.html>
>
> My analysis of the gamma function that
"best" fits L* may be found > here:
> <http:
//www.brucelindbloom.com/CompandCalcHelp.html#BestGammaForLab>
>
> Finally, I have a deeper analysis of the L*
function (actually a > grafting
> together of two functions) which may be found
here:
> <http:
//www.brucelindbloom.com/LContinuity.html>
Chris Murphy
Color Remedies (TM)
www.colorremedies.com/realworldcolor
____________________________________________________________________________
Date: Tue, 11 Feb 2003 23:35:27 EST
From: Stephen Ray
Subject: Re: Best RGB space for CMYK output
on 2/11/03 12:37 AM, J Walton wrote:
I work for a prepress company which has moved to an
RGB workflow. We scan
and retouch in DonRGB, but all of our output is CMYK.
We never have a use
for RGB as a final product. I wonder if we've
chosen the wrong working
space.
If there is no surprising contrast or color shift,
then DonRGB could be fine but look closely at banding when moding to CMYK.
Different scan profiles, work spaces, output profiles, and their
combinations, exhibit better or worse banding. By the way, you're not going
find banding problems by scanning an IT-8 Target. (There's no blends.)
And of course, never say never. If you don't have a
use for RGB scans I would venture to say your clients do, especially if
they know the milage they could get from them. Don't your clients have a
web site, publicity efforts, PowerPoint presentations, etc., anything other
than CMYK printing?
-Stephen Ray
____________________________________________________________________________
Date: Wed, 12 Feb 2003 07:26:11 -0500
From: John Castronovo
Subject: Re: Best RGB space for CMYK output
We've been converting all our work to DonRGB for
several years now with no ill effects seen or reported. The only concern is
that some people refuse to USE THE PROFILE when they open our work, even
though it's embedded.
john castronovo
tech photo & imaging
____________________________________________________________________________
Date: Wed, 12 Feb 2003 13:02:19 EST
From: Dan Margulis
Subject: Re: Gamma in LAB
Stephen writes,
Is there a definitive published source ANYWHERE on
this? 2.5 or 3 is
the closest thing I have read in print, and quick
tests seem to back
this up whe examing USM, but I have not compared
luminance levels
lost in various RGB gammas to LAB to try to see which
RGB looses the
same amount of unique levels (as a rough indication of
the approx
gamma, not that I know if this is an accurate way to
establish gamma
of L of LAB, I am just running with what I think I
know! <g>).
The L doesn't behave comparably to RGB channels. It
devotes relatively less space to extreme highlights and shadows, thus it
can be likened to a standard channel to which an S-curve has been applied.
This appears to be part of its effectiveness in sharpening.
Granted that a direct comparison has to be misleading,
if I'm forced to pick a number, I'd say that the L channel is very roughly
equivalent to RGB at a gamma of between 2.6 and 2.7.
Dan Margulis
____________________________________________________________________________
Date: Wed, 12 Feb 2003 15:51:10 -0800
From: J Walton
Subject: RE: Best RGB space for CMYK output...continued
Thanks to all for their replies, they were very
helpful.
Perhaps I should explain my reason for doubting
DonRGB. My concern is that using Perceptual rendering (which normally
looks best), going from a wide space to a small space (SWOP) will result in
banding. And we have had occasional problems with banding.
There is a limit to the total number of unique colors
in an 8-bit RGB file. Since I only care about SWOP output, then I want my
bits focused on the smallest possible area while containing the SWOP gamut.
If I use Wide Gamut RGB I am intentionally limiting the total number
of usable (CMYK) numbers in the file, am I not?
I'm not sure I understand why I need to choose my
working RGB space based on my scanner's space. The final CMYK output
is the ONLY thing I sell my clients, so it's the ONLY thing that matters to
me. Shouldn't I choose a working space based on the final output?
Theoretically I can see a benefit to having a working
or archive file in a large space, but I don't work in Theory Land, and my
clients don't buy theoretical images. If DonRGB is causing or
emphasizing banding, and it's bigger than I need for SWOP output, why
shouldn't I switch?
J Walton
____________________________________________________________________________
Date: Wed, 12 Feb 2003 17:19:22 -0700
From: Chris Murphy
Subject: Re: Best RGB space for CMYK output...continued
On Wednesday, February 12, 2003, at 04:51 PM, J Walton
wrote:
If DonRGB is causing or emphasizing banding, and it's
bigger than I need for SWOP output, why shouldn't I
switch?
I'd be suspicious that there is banding already in the
file, and a larger space like DonRGB may be exacerbating a preexisting
problem. If you have such a problem in the future, I would reassign a
profile such as Adobe RGB and reseparate. While the color will be a little
different due to just reassigning the profile, you will be making an
apples-apples comparison with this method: the point is to see if a
different source profile associated with the original numeric values
eliminates the posterization problem.
I have yet to see matrix based source profiles CAUSE
posterization/banding. But I have seen larger space source profiles
exacerbate posterization that was already in the file. And really, this
problem is more commonly caused by a problematic destination profile. That
is, perhaps a smoother destination profile could be used with the same data
and the wider space source profile.
Chris Murphy
Color Remedies (TM)
www.colorremedies.com/realworldcolor
____________________________________________________________________________
Date: Wed, 12 Feb 2003 20:50:59 EST
From: Dan Margulis
Subject: Re: Best practice for RGB stock images?
Jim Rich writes,
Profiles are just one part of the process that helps
businesses communicate
color more efficiently. The process will work without
them it will just take
longer to get it done. It sounds like want is missing
from your post is the
part where you use common sense when working with
profiles and then some
skill and to get the color correct.
Right on target, just as the other replies from Terry
and Chris were. However, lest it seem that we're ganging up on Jono, let me
point out that he was responding to considerable provocation and may have
overstepped somewhat in his reply.
What Jim, Terry, Chris and I say is typical of what
those knowledgeable in the field believe here in the year 2003. What Jono
responded to was more typical of 1998 or early 1999: "Of course, the
real problem is that people still refuse to embed and use profiles...Who
has the power to change an industry so rigidly stuck in stupidity?"
The statement pointed the usual fingers at the stupid printers and stupid
service bureaus. All that was missing was the usual "you have to
understand the technology is in its infancy" and "what you really
should be doing is educating your clients rather than putting your head in
the sand."
Jono wasn't talking about his own personal settings or
how to calibrate his own devices. He was speaking of the viability of using
profiles to interchange documents with total strangers. In that limited
area, he's right: printers and SBs have concluded, quite rightly in
my view, that this is an ineffective, costly, and error-prone way to do
things. And in any event there are so few clients who know what they're
doing with embedded profiles that the printers feel little need to pay
attention.
Speaking as one of the persons so rigidly stuck in
stupidity that I ordinarily refuse to embed profiles, however, let me
reiterate that there *are* many good uses for the technology and those who
don't understand what profiles do are unnecessarily limiting their options.
Dan Margulis
____________________________________________________________________________
Date: Wed, 12 Feb 2003 21:06:09 EST
From: Dan Margulis
Subject: Re: Best RGB space for CMYK output...continued
J writes,
I'm not sure I understand why I need to choose my
working RGB space based on
my scanner's space. The final CMYK output is the
ONLY thing I sell my
clients, so it's the ONLY thing that matters to me.
Shouldn't I choose a
working space based on the final output?
Yes, which is why this thread is so mystifying. It
strikes me as like saying that your company has decided that you should
drive while upside down and you need our advice as to what brand of socks
will give your toes the best hold of the steering wheel.
If you own a printer that wants RGB input, you want to
work in RGB unless there's some image-specific reason to go elsewhere. The
same applies here. Why on earth would you want to make *any* RGB your
primary workspace, if you are *only* concerned with output in CMYK?
The first choice, therefore, is to work mostly in
CMYK, reserving the option of RGB and/or LAB where appropriate. The second
choice would be some RGB that bears some relation to the CMYK gamut: sRGB,
Apple RGB, or ColorMatch RGB. The third choice would be something wider
gamut like Adobe RGB, which introduces a lot of gamut problems but makes it
somewhat easier to get "acceptable" color. The fourth choice is
LAB, which is even harder to work with but offers certain unique
advantages.
If CMYK is your only concern, the eighty-sixth choice
is to work in some ultra-wide-gamut RGB, which combines all of the
disadvantages of 2 through 4 in one colorful package.
Dan Margulis
____________________________________________________________________________
Date: Wed, 12 Feb 2003 19:56:53 -0800
From: J Walton
Subject: RE: Best RGB space for CMYK output...continued
I think Dan's argument makes a lot of sense (except
for the sock thing ;-), especially since until now I haven't explained the
use of RGB.
We quite frequently need to repurpose the same image
for a variety of different CMYK outputs. We retouch the image and it
goes first to Time magazine, later on it goes to USA Today, and later still
it prints sheetfed on glossy stock. We want the advantage of using
one worker file and easily moving to 300 DMAX, 240 DMAX, and 340 DMAX.
We also like the advantage of being able to automatically compensate
for different proofing material and base (paper). We could use CMYK
for that, just not quite as easily.
The #1 reason for having an RGB worker is retouching.
We do a TON of retouching, and as a retoucher, it's a heck of a lot
easier to retouch in RGB than CMYK. Any time you have to repaint a
car from scratch you want RGB. Giant color corrections almost require
RGB (or LAB), if for no other reason than to get a new black. Since
RGB is so incredibly similar to CMYK for color correction, there's not much
reason to avoid RGB. In fact, we find that most color corrections are
a lot more natural in RGB, since you avoid dealing with UCR.
The only problem we've had so far is banding, and that
only occasionally.
------
Let me change gears, Dan, because I want some feedback
on your second and third choice below.
I like using the smallest possible RGB space, but I'm
not inclined to use something that will clip too much for CMYK output.
sRGB, and to a lesser extend, ColorMatch seem to do just that.
Since I am mostly concerned with the final CMYK file, I don't want to
do anything to jeopardize that. Wouldn't clipping pure cyans and yellows do
that?
According to Bruce Lindbloom, Adobe RGB and NTSC are
the smallest RGB spaces that contain SWOP CMYK (Adobe RGB comes super
close). I'm inclined to switch to Adobe RGB, mainly because it's so
common.
What specific disadvantages do you see with Adobe RGB?
Always thankful,
J Walton
____________________________________________________________________________
Date: Wed, 12 Feb 2003 23:00:17 -0500
From: Terry Wyse
Subject: Re: Best RGB space for CMYK output...continued
on 2/12/03 6:51 PM, J Walton wrote:
I'm not sure I understand why I need to choose my
working RGB space based on
my scanner's space. The final CMYK output is the
ONLY thing I sell my
clients, so it's the ONLY thing that matters to me.
Shouldn't I choose a
working space based on the final output?
I'll try to make this as succinct as I can:
If you move the image from a relatively wide scanner
space to a too-small RGB working space, you will have potentially clipped
many of the saturated colors that contained detail in the original scan. In
scanner-speak, you will have lost "shape" and "drawing"
in these saturated colors that you can NEVER get back no matter what you do
to the final CMYK image.
If the RGB working space is JUST large enough to hold
all the colors your scanner is capable of "seeing" without
clipping, you've got half a chance of maintaining shape and detail in those
same saturated colors when you make your final move to CMYK. Sure, you'll
have to make some compromises but at least you'll have choices (rendering
intents) what to do about the detail/shape in those saturated colors.
If it was me, I'd rather HAVE this shape and detail to
start with and THEN decide where and what I'm going to "throw
away" once I go to CMYK rather than never having this extra shape and
detail to begin with. Your choice.
BTW, DonRGB is not all THAT wide of a working space.
It's larger than AdobeRGB but nothing near what Wide Gamut RGB and Pro
Photo RGB are in terms of size.
Terry
--
__________________________________
WyseConsul
Color Management Consulting
v 704.843.0858
____________________________________________________________________________
Date: Thu, 13 Feb 2003 08:05:11 -0600
From: "Susan and John Opitz"
Subject: Re: Best RGB space for CMYK output...continued
It strikes me as like saying that your company has
decided that you should drive while upside down and you need our advice as
to what brand of socks will give your toes the best hold of the steering
wheel.
I could'nt let this one go by. I was drinking
coffee this morning while reading this and I find out that when reading
your posts to make sure I have no liquids near the monitor. Your a trip,
Mr. Margulis. Very funny.
John Opitz
____________________________________________________________________________
Date: Thu, 13 Feb 2003 09:45:02 -0500
From: Dolores Kaufman
Subject: Re: Best RGB space for CMYK output...continued
on 2/12/03 11:00 PM, Terry Wyse wrote:
BTW, DonRGB is not all THAT wide of a working space.
It's larger than
AdobeRGB but nothing near what Wide Gamut RGB and Pro
Photo RGB are in terms
of size.
Terry, do you (or does anyone?) have any idea what RGB
working space is
closest to the output of an Epson printer? I have a
new 2200. I have been
using Adobe 1998 for images targeted for fine art
prints & cards, but this
discussion has me wondering if I should be choosing a
wider space.
Thanks, Dolores
____________________________________________________________________________
Date: Thu, 13 Feb 2003 14:51:50 -0000
From: Pete Merck
Subject: Re: Best RGB space for CMYK output...continued
--- Terry Wyse wrote
If you move the image from a relatively wide scanner
space to a too-small
RGB working space, you will have potentially clipped
many of the saturated
colors that contained detail in the original scan. In
scanner-speak, you
will have lost "shape" and
"drawing" in these saturated colors that you can
NEVER get back no matter what you do to the final CMYK
image.
This is exactly why I created my own rgb work/storage
space. After comparing gamuts (thank you Colorthink and Colorblind)I
found that my scanner gamut extended past many rgb spaces in Y/red side.
Rather than clipping or compressing to fit a rgb space once then
doing it again to CMYK , I made a rgb space so that it only had to compress
once.
If it was me, I'd rather HAVE this shape and detail to
start with and THEN
decide where and what I'm going to "throw
away" once I go to CMYK rather
than never having this extra shape and detail to begin
with. Your choice.
Several years ago and spending many days testing
scanner setups for profiling I said to shocked co-workers: 'Screw the
color, I can always change that, but lost detail is something I can't get
back.'
Pete Merck
____________________________________________________________________________
Date: Thu, 13 Feb 2003 09:19:50 -0600
From: David.Clark
Subject: Re: Best RGB space for CMYK output
ECI-RGB was developed expressly for the sheetfed
gamut. DonRGB was developed for scanning film.
http://www.eci.org/eng/index_e.htm
____________________________________________________________________________
Date: Thu, 13 Feb 2003 08:20:10 -0700
From: Andrew Rodney
Subject: Re: Best RGB space for CMYK output...continued
on 2/12/03 8:56 PM, J Walton wrote:
The only problem we've had so far is banding, and that
only occasionally.
(here comes a hot potato) Do you capture and edit in
high bit (more than 8 bits pre color)?
Andrew Rodney
____________________________________________________________________________
Date: Thu, 13 Feb 2003 08:16:07 -0700
From: Andrew Rodney
Subject: Re: Best RGB space for CMYK output...continued
on 2/12/03 7:06 PM, Dan Margulis wrote:
If you own a printer that wants RGB input, you want to
work in RGB unless
there's some image-specific reason to go elsewhere.
The same applies here.
Why on earth would you want to make *any* RGB your
primary workspace, if you
are *only* concerned with output in CMYK?
Well every capture device on the planet captures in
RGB (you may have a device that does an on the fly conversion in which case
the discussion is moot anyway). The definition of RGB will and does play a
profound role on the eventual CMYK you get when you convert a file (which
is done with profiles; like it or not).
The first choice, therefore, is to work mostly in
CMYK, reserving the option
of RGB and/or LAB where appropriate…
The fourth choice is LAB, which is even harder to work
with but offers certain unique advantages.
We got to CMYK from RGB how? Eliminating a step
doesn1t alter the steps prior to conversion. Same with LAB.
If CMYK is your only concern, the eighty-sixth choice
is to work in some
ultra-wide-gamut RGB, which combines all of the
disadvantages of 2 through 4
in one colorful package.
The answer for most people is pretty simple. Set
Photoshop to 3U.S. Pre Press Defaults2 and work that way (Adobe RGB seems
to be a very workable space for CMYK output among other output needs). I
still believe that for 95% of users (all users), that default setting will
work just fine. Set it, forget it and go on with your life.
Andrew Rodney
____________________________________________________________________________
Date: Thu, 13 Feb 2003 13:20:43 -0500
From: Jim Rich
Subject: Re: Best RGB space for CMYK output...continued
Dolores wrote:
Terry, do you (or does anyone?) have any idea what RGB
working space is
closest to the output of an Epson printer? I have a
new 2200. I have been
using Adobe 1998 for images targeted for fine art
prints & cards, but this
discussion has me wondering if I should be choosing a
wider space.
Dolores,
One of the defining factors that control the gamut of
a printer is the ink paper combination. If you use bright papers such as
glossy or semigloss you stand a good chance to get a large color gamut.
Change the paper to an art paper that is yellow and dull then you probably
have clipped your color gamut and it becomes quite small.
So you want to look at your printing needs and then
consider your working space.
Jim Rich
____________________________________________________________________________
Date: Thu, 13 Feb 2003 14:01:31 EST
From: Dan Margulis
Subject: Re: Best RGB space for CMYK output...continued
J writes,
We quite frequently need to repurpose the same image
for a variety of
different CMYK outputs. We retouch the image and
it goes first to Time
magazine, later on it goes to USA Today, and later
still it prints sheetfed
on glossy stock. We want the advantage of using
one worker file and easily
moving to 300 DMAX, 240 DMAX, and 340 DMAX. We
also like the advantage of
being able to automatically compensate for different
proofing material and
base (paper). We could use CMYK for that, just
not quite as easily.
I don't see why. You have to do a Convert to Profile
one way or another.
The #1 reason for having an RGB worker is retouching.
We do a TON of
retouching, and as a retoucher, it's a heck of a lot
easier to retouch in
RGB than CMYK. Any time you have to repaint a
car from scratch you want
RGB.
*You* may want RGB. I would want LAB.
I like using the smallest possible RGB space, but I'm
not inclined to use
something that will clip too much for CMYK output.
sRGB, and to a lesser
extend, ColorMatch seem to do just that. Since I
am mostly concerned with
the final CMYK file, I don't want to do anything to
jeopardize that.
Wouldn't clipping pure cyans and yellows do that?
No. The pure cyans that are being clipped are
typically things that are >95c<5m<5y. But even saying that it
clips anything >90c<10m<10y, you could work a lifetime and see
that color in a picture maybe a dozen times. It's a color that doesn't
exist for all practical purposes.
As for the yellow, yes, <10c<10m100y does exist
in things like bananas etc. However, the usual result is that the yellow
ink is reduced during separation to something below 100%. You just put it
back, or even leave it alone--yellow ink contributes so little to contrast
that it doesn't matter whether it's solid.
So, in short, these are not real-world disadvantages
at all, let alone disadvantages of the magnitude of having to deal with a
ton of out-of-CMYK-gamut colors.
What specific disadvantages do you see with Adobe RGB?
We had a thread on this less than a month ago, so I'll
be brief: too much space devoted to colors that are worthless for
your purposes, clunkiness as a correction space because the channels are
more powerful than in smaller RGBs, and much more so than in any CMYK.
Dan Margulis
____________________________________________________________________________
Date: Thu, 13 Feb 2003 15:10:39 -0500
From: Dolores Kaufman
Subject: Re: Best RGB space for CMYK output...continued
Thanks Jim,
I have been using Epson's Enhanced Matte paper. It has
a nice white, though matte surface. I've been pleased with the results so
maybe I should just stick with what I have been doing. Always looking to
improve where I can, though <g>.
Dolores
____________________________________________________________________________
Date: Thu, 13 Feb 2003 16:24:33 -0500
From: Terry Wyse
Subject: Re: Best RGB space for CMYK output...continued
on 2/13/03 9:45 AM, Dolores Kaufman wrote:
Terry, do you (or does anyone?) have any idea what RGB
working space is
closest to the output of an Epson printer? I have a
new 2200. I have been
using Adobe 1998 for images targeted for fine art
prints & cards, but this
discussion has me wondering if I should be choosing a
wider space.
Impossible to say. Each printer/ink/paper combination
is unique.
In checking out a few of my 2200 "RGB"
custom profiles, the color gamut ranges roughly from AdobeRGB (Photo Gloss
paper) to smaller than sRGB (Enhanced Matte paper) in most areas. If you're
using fine art papers, you've likely nothing to worry about. If anything,
AdobeRGB might be a bit TOO wide for most fine art papers.
Terry
--
__________________________________
WyseConsul
Color Management Consulting
v 704.843.0858
__________________________________
____________________________________________________________________________
Date: Thu, 13 Feb 2003 23:28:44 -0500
From: John Castronovo
Subject: Re: Best practice for RGB stock images?
Dan Margulis wrote:
Jono wasn't talking about his own personal settings or
how to calibrate his
own devices. He was speaking of the viability of using
profiles to
interchange documents with total strangers. In that
limited area, he's right:
printers and SBs have concluded, quite rightly
in my view, that this is an
ineffective, costly, and error-prone way to do things.
And in any event there
are so few clients who know what they're doing with
embedded profiles that
the printers feel little need to pay attention.
They're welcome to ignore it if they want to, but
what's the harm of embedding them? It's like saying that lot's of people
can't drive so we should get rid of roads. And where are all these
incorrect source profiles? Since Photoshop 6 I haven't seen many. In my
shop, we see thousands of images and the only ones we have real surprises
with are the ones without profiles. If we see an image that doesn't look
correct with the embedded profile, we call the client for confirmation.
Many times, that's the way he wanted it to look!
What you might think is a white poodle in the photo
might actually be dyed pink. If you saw such a scan would you assume that
it was off color and correct it? If it had an embedded profile, and you
used it, and it still looked pink, then you would rightly conclude that it
was a pink dog.
Speaking as one of the persons so rigidly stuck in
stupidity that I
ordinarily refuse to embed profiles, however, let me
reiterate that there
*are* many good uses for the technology and those who
don't understand what
profiles do are unnecessarily limiting their options.
Well at least I got minor concession <g>.
john castronovo
____________________________________________________________________________
Date: Fri, 14 Feb 2003 03:38:08 -0800
From: "Raymond E. McKinley"
Subject: Best space for CMYK output
Terry Writes
In checking out a few of my 2200 RGB custom
profilesthe color gamut ranges roughly from Adobe RGB to smaller than sRGB
How did you arrive at the size of your profiles.
Recently after reading RWCM I downloaded Profile Maker and used the measure
tool to check the size of my profiles. According to Profile Maker all of my
1270 and S9000 EZ Color profiles are smaller than sRGB, according to the
Chromix Gamut Viewer all of these profiles are larger than sRGB, some are
even larger than Adobe RGB. How accurate are these devices for measuring
gamut.
If 2 versions of each file are viewed using the Soft
Proof to compare the EZ Color profiles to the canned profiles (
which are identical to sRGB according to Profile Maker) the EZ Color
profiles display brighter more saturated colors and they also maintain the
difference in print.
My reason for asking is that I understand from RWCM
that you can use an Epson for proofs if you make and Absolute Colorimetric
conversion the the print space, assuming that the Epson's gamut is wider
than SWOP.
Raymond
____________________________________________________________________________
Date: Fri, 14 Feb 2003 09:43:25 -0500
From: Dolores Kaufman
Subject: Re: Best RGB space for CMYK output...continued
on 2/13/03 4:24 PM, Terry Wyse wrote:
In checking out a few of my 2200 "RGB"
custom profiles, the color gamut
ranges roughly from AdobeRGB (Photo Gloss paper) to
smaller than sRGB
(Enhanced Matte paper) in most areas. If you're using
fine art papers,
you've likely nothing to worry about. If anything,
AdobeRGB might be a bit
TOO wide for most fine art papers.
Thanks Terry,
I had no idea the gamut was that small!
Dolores
____________________________________________________________________________
Date: Fri, 14 Feb 2003 11:02:15 -0500
From: Terry Wyse
Subject: Re: Best space for CMYK output
on 2/14/03 6:38 AM, Raymond E. McKinley wrote:
How did you arrive at the size of your profiles.
Recently after reading RWCM I
downloaded Profile Maker and used the measure tool to
check the size of my
profiles. According to Profile Maker all of my 1270
and S9000 EZ Color
profiles are smaller than sRGB, according to the
Chromix Gamut Viewer all of
these profiles are larger than sRGB, some are even
larger than Adobe RGB. How
accurate are these devices for measuring gamut.
I think you must have used "Profile Editor"
to look at the gamuts and not "Measure Tool". I used ColorThink
2.0 but I know that different apps will display the 2D gamuts in not
exactly the same way. When you brought that up, I took my 2200 profiles
(made with ProfileMaker 4.1.1) into three applications (Colorthink, Profile
Editor and icc ToolBox Pro) and compared them to AdobeRGB at the same time.
All three apps showed a slightly different 2D gamut rendering for not only
my 2200 profiles, but also for AdobeRGB! Weird.
Terry
__________________________________
WyseConsul
Color Management Consulting
v 704.843.0858
__________________________________
____________________________________________________________________________
Date: Fri, 14 Feb 2003 09:25:18 -0700
From: Ron Kelly
Subject: Re: Best practice for RGB stock images?
John C wrote:
What you might think is a white poodle in the photo
might actually be dyed
pink. If you saw such a scan would you assume that it
was off color and
correct it? If it had an embedded profile, and you
used it, and it still
looked pink, then you would rightly conclude that it
was a pink dog.
John, I'm not sure this is such a good example; or
maybe, it is. I will NEVER blindly trust a technology to the extent that a
poodle that looks pink will pass through my hands untouched, just because
the technology says that it supposed to look that way!
The whole thing with profiles is way too complex.
Sure, in theory, I understand what they're supposed to
do. In theory, atomic energy is fairly straightforward, too. In practice,
it's very complex.
Now, you are advocating that it's good to use them
somewhere, but not everywhere. I too, find that profiles are helpful
sometimes. Other times, they just seem to be another reason to tear my hair
out.
I don't want to unncessarily limit my options, but I'm
not sure just where and where not to use profiles. And the real problem is,
it's a moving target, isn't it? What's the best practice today will be
different tomorrow.
So, the world waits and watches, knowing that some of
this new technology is good some of the time. The rest of the time, it
seems like we're being forced to learn Esperanto.
Ron Kelly
____________________________________________________________________________
Date: Fri, 14 Feb 2003 13:41:35 -0700
From: Andrew Rodney
Subject: Re: Best practice for RGB stock images?
on 2/14/03 9:25 AM, Ron Kelly wrote:
John, I'm not sure this is such a good example; or
maybe, it is. I will
NEVER blindly trust a technology to the extent that a
poodle that looks
pink will pass through my hands untouched, just
because the technology
says that it supposed to look that way!
You have two possibilities here:
One is the file comes tagged and the dog looks pink. I
can assume, using sound color management practices and setting up Photoshop
properly that the person who sent this file wanted a pink dog. We are
seeing the same previews.
The second is to have no CMS in place and just guess
at what the preview OR intent was. I know plenty of photographers who would
go out of their way to shoot a pink dog (check out the work of Chip Simon1s
of good old New Mexico - http://www.chipsimons.com/).
Andrew Rodney
____________________________________________________________________________
Date: Fri, 14 Feb 2003 17:15:04 EST
From: Dan Margulis
Subject: Re: Best practice for RGB stock images?
John Castronovo writes,
They're welcome to ignore it if they want to, but
what's the harm of
embedding them?
With respect to RGB profiles, I'm not aware of any
harm per se other than file size. Occasional problematic behavior with CMYK
and especially with grayscale profiles has been widely reported.
The real harm in embedding is that somebody may act on
them. And with so very few people knowing anything about how they operate,
that's a real risk. It doesn't take too many jobs ruined by misinterpreted
profiles to persuade practical people to stop embedding them. Personally,
I've already reached that quota. If it's a CMYK file, I definitely
don't want anybody to convert it without checking with me first. If
it's RGB, I'm damned if I do and damned if I don't, so I never give out
corrected RGB files. I convert to LAB first. If the next person can't
figure out what to do with the LAB file he certainly can't be trusted to
interpret embedded RGB profiles properly.
And where are all these incorrect source profiles?
Since Photoshop 6 I
haven't seen many.
That, of course, will depend on who your clients are.
You sound highly fortunate in this regard.
What you might think is a white poodle in the photo
might actually be dyed
pink. If you saw such a scan would you assume that it
was off color and
correct it?
Only someone with no familiarity with correction
techniques would assume that. As I am somewhat familiar with them, there
would be no assuming involved--it would be immediately obvious that the dog
should be pink.
If it had an embedded profile, and you used it, and it
still looked pink,
then you would rightly conclude that it was a pink
dog.
Whether it "looks" pink is irrelevant. Human
beings don't evaluate neutrals well. That's why we have an info palette. If
the dog is truly supposed to be pink, and the operator can't detect it,
that person shouldn't be attempting to mess with color in a professional
environment.
The more pertinent example is if the dog had been dyed
six months ago and it had mostly worn off, so that the dog was basically
white but had a slight pink tinge that isn't typical of white poodles. In
that case, I would indeed be fooled. What would happen then is as follows:
1) If told not to touch the job but merely output it
as is, no issue, profile or no profile. Slightly pink dog.
2) If told to correct the job, no profile attached,
then I am on notice that the client feels that certain colors may be
erroneous and that I am to use best judgment in correcting them. So I
change the dog to white.
3) If told to correct the job, profile attached, then
I am on notice that the client feels that certain colors may be erroneous,
however, the error has been characterized and calibrated, and the color is
now reliably, predictably, and consistently erroneous rather than randomly
erroneous as in #2. So I change the dog to white.
Dan Margulis
P.S. Furthermore, I assume that this pink dog is found
in an RGB file. While I defer to Chris Murphy on this point, AFAIK
Photoshop can't work with RGB profiles in which R=G=B isn't neutral. So,
the dog would be pink no matter what profile was used and the whole
discussion is pointless.
P.P.S. And if the client, unlike me, knows how to use
an RGB profile in which R=G=B isn't neutral, and is handing such jobs off
to strangers without telling them about it, then he is clearly a masochist
who *wants* the file to be mishandled. Why should we disappoint him?
____________________________________________________________________________
Date: Fri, 14 Feb 2003 16:55:06 -0700
From: Andrew Rodney
Subject: Re: Best practice for RGB stock images?
on 2/14/03 3:15 PM, Dan Margulis wrote:
P.S. Furthermore, I assume that this pink dog is found
in an RGB file. While
I defer to Chris Murphy on this point, AFAIK Photoshop
can't work with RGB
profiles in which R=G=B isn't neutral.
Sure it can, and it does so all the time.
Andrew Rodney
____________________________________________________________________________
Date: Fri, 14 Feb 2003 15:28:53 -0700
From: Chris Murphy
Subject: Re: Best space for CMYK output
On Friday, February 14, 2003, at 04:38 AM,
Raymond E. McKinley wrote:
My reason for asking is that I understand from RWCM
that you can use
an Epson for proofs if you make and Absolute
Colorimetric conversion
the the print space, assuming that the Epson's gamut
is wider than
SWOP.
Yes, but be sure you are doing gamut comparisons in 3D
for the reasons illustrated on page 77. 2D gamut comparisons can be very
misleading.
Chris Murphy
Color Remedies (TM)
www.colorremedies.com/realworldcolor
____________________________________________________________________________
Date: Fri, 14 Feb 2003 18:04:02 -0700
From: Chris Murphy
Subject: Re: Best practice for RGB stock images?
On Friday, February 14, 2003, at 03:15 PM, Dan
Margulis wrote:
The real harm in embedding is that somebody may act on
them. And with so very
few people knowing anything about how they operate,
that's a real risk.
I think we're getting to the point where there are so
many different kinds of devices with such different behavior among them,
that it's as dangerous to ignore the embedded profile. To leave it in some
other device space, and print on a new device is increasingly problematic.
Some workflows where source CMYK images are separate
for some kind of reasonable press condition, and the new destination is
some kind of reasonable press condition, will likely get away with ignore
embedded profiles just fine. But when the data is meant for a truly
different printing process, ignoring the embedded profile will likely be a
problem. Use the profile and it might be a problem.
Fonts and font problems have been around for a really
long time, and no one says don't embed font or don't use fonts. There are
methods for dealing with font problems and while it's a pain in the rear to
have all of this font paraphernalia in a typical prepress workflow, that's
the way it is in order to solve font problems on a job, and just get them
to print right.
It's similar for profiles, except that the service
bureau quality troubleshooting and repair tools for profiles is not
anywhere near the maturity level for fonts. (How long have we had fonts,
how long have we had profiles? And is it possible to ignore font problems?
No. Is it possible to ignore profile problems? Yes, there are work
arounds.)
It doesn't take too many jobs ruined by
misinterpreted profiles to persuade
practical people to stop embedding them. Personally,
I've already reached
that quota.
I think you need to reset your counter and start over
to see what happens. This isn't the Photoshop 5 era where it was easy to
embed the wrong profile. I don't have any statistics on this, but I just
don't see people willfully embedding the wrong profile into images. It's
not that easy to do anymore.
If it's RGB, I'm damned if I do and
damned if I don't, so I never give out corrected RGB
files. I convert to LAB
first. If the next person can't figure out what to do
with the LAB file he
certainly can't be trusted to interpret embedded RGB
profiles properly.
The difference between a random RGB image (maybe it
has a profile, maybe not, maybe the profile is wrong) and a LAB image is
that the LAB image as an implicit source profile associated with it. So it
effectively has a guaranteed correct source profile. If the destination
profile is wrong, the separation will still be wrong with a LAB image, so
YES if he can't convert the LAB image correctly, he's not going to convert
RGB images correctly either.
But, even if you have a LAB image, and a good
separation does not mean that the output will look like what you saw on the
display. The critical point is that it requires a calibrated/profiled
display in order for the LAB image to be trustworthy.
So if the display is calibrated and profiled, and the
destination profile is correct, the advantage of LAB is only in its implied
source profile always being right. So how can an RGB image's profile be
wrong in a case where a calibrated/profiled monitor is being used and the
user likes what they see on-screen? I think it's vastly more likely that
the source profile for an RGB image is going to be because the WRONG
PROFILE IS ASSUMED - and profile assumption happens only in two cases:
1. The embedded profile is ignored.
2. There is no embedded profile.
P.S. Furthermore, I assume that this pink dog is found
in an RGB file. While
I defer to Chris Murphy on this point, AFAIK Photoshop
can't work with RGB
profiles in which R=G=B isn't neutral. So, the dog
would be pink no matter
what profile was used and the whole discussion is
pointless.
Photoshop 6 and higher can use table-based RGB
profiles as editing spaces, so it is possible to work in an RGB space that
is not gray balanced.
I'm not exactly sure what limitation Photoshop 5 and
earlier had. It's possible to have a matrix-based profile that is not gray
balanced (if the tone response curves are not the same), but I think
Photoshop 5 would only use matrix-based profiles that *also* had a single
tone response curve that applied to all three channels.
Chris Murphy
Color Remedies (TM)
www.colorremedies.com/realworldcolor
____________________________________________________________________________
Date: Fri, 14 Feb 2003 20:40:38 -0800
From: "Raymond E. McKinley"
Subject: Best space for CMYK output
Terry writes
All three apps showed a slightly different 2D Gamut
rendering for not only my 2200 profiles but also for Adobe RGB weird
Terry thanks for the info, you were right I did use
the Profile Editor and not the Measure Tool. I guess one of these days the
reason for these differences will show up, as sometimes happens.
Raymond
____________________________________________________________________________
Date: Fri, 14 Feb 2003 22:14:32 -0500
From: John Castronovo
Subject: Re: Best practice for RGB stock images?
I'd like to add that this was a true story borrowed
from the analog world.
It happened to Kodak some years ago when a strange
negative was sent up to the wizards in Rochester. The lab couldn't get the
color right - the poodle was pink or everything else was off color. It
looked like a classic case of color crossover in the negative. They worked
on it for days, and fearing that a bad emulsion of film had gotten out,
they retouched the photo through masking. They were shocked when the
customer complained about the 'corrected' print. Her dog was actually dyed
pink.
Maybe this is a bad example for digital, but the point
is still valid. I recently got a bunch of files to print. They were of
abstract art, and there was no way to judge the validity of the color we
were getting. An embedded profile would've been much appreciated.
john castronovo
____________________________________________________________________________
Date: Sat, 15 Feb 2003 13:54:30 EST
From: Dan Margulis
Subject: Re: Best practice for RGB stock images?
Chris writes,
I think we're getting to the point where there are so
many different
kinds of devices with such different behavior among
them, that it's as
dangerous to ignore the embedded profile.
This has zero to do with the paragraph you were
responding to, which was a statement that I personally do not tag my files.
Nobody was advocating ignoring embedded profiles,
although in fairness, the proportion of users who tag files correctly is so
infinitesimal that I can understand why printers do ignore them, and I also
understand why they tend to view the existence of an embedded profile as a
suggestion that the user is unskilled. But, I do agree that they
should at least take notice that a tag is there.
So if the display is calibrated and profiled, and the
destination
profile is correct, the advantage of LAB is only in
its implied source
profile always being right.
The state of the monitor and the destination profile
are academic. If I pass an RGB file on to any given stranger I'd bet that
the chances are at least 25% that his RGB setup is such that my file will
be misinterpreted, probably higher if the stranger is a printer. And
in that case disaster is guaranteed. Passing LAB instead eliminates the
risk.
I'm not exactly sure what limitation Photoshop 5 and
earlier had. It's
possible to have a matrix-based profile that is not
gray balanced (if
the tone response curves are not the same), but I
think Photoshop 5
would only use matrix-based profiles that *also* had a
single tone
response curve that applied to all three channels.
I think so too. I definitely remember Bruce saying
once that Photoshop required that but it may have been v5 only. In any
event, I've never personally met a file tagged with a such a profile, but
Andrew says it happens all the time, so I suppose it must be so. I
reiterate that anybody who tags his files that way and then passes them on
to strangers without discussion is not merely wearing a big "Hurt
Me" sign but is falling to his knees, offering a fervent prayer that
his job will be screwed up, and then standing back up, passing out whips to
all bystanders, dropping his trousers, and bending over a barrel.
Dan Margulis
____________________________________________________________________________
Date: Sat, 15 Feb 2003 14:14:19 -0700
From: Andrew Rodney
Subject: Re: Best practice for RGB stock images?
on 2/15/03 11:54 AM, Dan Margulis wrote:
... the
proportion of users who tag files correctly is so
infinitesimal that I can
understand why printers do ignore them...
The proportion therefore is what? Can you produce some
actual numbers or is this an 3educated2 guess?
I've never
personally met a file tagged with a such a profile,
but Andrew says it
happens all the time, so I suppose it must be so.
Many capture devices are not gray balanced with R=G=B
being a neutral. That1s not necessarily any problem at all if you intend to
go directly to an output space with no editing (or edit in the output
space). Conversion into a well behaved RGB editing space would be a good
idea if you need to do color corrections AND it1s important to know an
exacting recipe for gray balance. That1s not a requirement by any strength
of the imagination.
I reiterate that anybody
who tags his files that way and then passes them on to
strangers without
discussion is not merely wearing a big "Hurt
Me" sign
Set your color preferences to US PrePress defaults and
no harm can come!
Andrew Rodney
____________________________________________________________________________
Date: Sat, 15 Feb 2003 16:36:27 -0500
From: Andrew Darlow
Subject: Re: Best practice for RGB stock images?
Maybe this is a bad example for digital, but the point
is still valid. I
recently got a bunch of files to print. They were of
abstract art, and there
was no way to judge the validity of the color we were
getting. An embedded
profile would've been much appreciated.
john castronovo
Hi John:
Wouldn't a Macbeth chart or Kodak color wedge(assuming
light was a consistant temp and even across the art) in each shot have been
even better?
All the best!
Andrew Darlow
--
-------------------------
Photography, Digital Print Consulting and Custom
Editions
Andrew Darlow Images International
____________________________________________________________________________
Date: Sat, 15 Feb 2003 14:09:58 -0700
From: Chris Murphy
Subject: Re: Best practice for RGB stock images?
On Saturday, February 15, 2003, at 11:54 AM, Dan
Margulis wrote:
This has zero to do with the paragraph you were
responding to, which
was a statement that I personally do not tag my files.
What I'm responding to is the statement you made:
"The real harm in embedding is that somebody may act on them. And with
so very few people knowing anything about how they operate, that's a real
risk."
By itself, your statements are incomplete. Yes there
is a possibility of harm in embedding because someone down the line won't
know what they're doing. There is an increasing chance that not embedding
will also be harmful because the person down the line will have to make
assumptions that aren't appropriate.
In Real World Color Management, we used embedded
profiles for RGB images only, because we had multiple source profiles. But
once they were converted to CMYK, we had each of our apps to assume they
were using the press profile Bruce had created. But that profile was not
embedded into each CMYK image. And it was not because "the real hard
in embedding is that somebody may act on them." That was not the
reason we didn't embed. We didn't embed simply because it wasn't necessary,
and it would have caused a lot more data to get pushed through the workflow
for absolutely no benefit.
To avoid embedding just to prevent someone who doesn't
know what they are doing down the line from messing up the file isn't a
valid excuse. They need to get with the program and have a mechanism for
dealing with profiles.
Nobody was advocating ignoring embedded profiles,
although in fairness, the
proportion of users who tag files correctly is so
infinitesimal that I can
understand why printers do ignore them,
On what basis are you claiming an infinitesimal number
of improperly tagged images? Perhaps you'd like to define what makes a file
properly tagged versus improperly tagged?
The state of the monitor and the destination profile
are academic.
Duplicate an RGB image and convert it to LAB. Both
will look the same. Result, no advantage to the LAB file yet. If the
monitor isn't calibrated/profiled, the LAB file gains you nothing at this
point. If the monitor is too dark, and you correct the files to lighten
them up, in both cases the printed CMYK result from both files will be too
light and washed out.
If the destination profile is wrong, the separation
will be wrong. The destination profile is definitely not academic.
If I pass
an RGB file on to any given stranger I'd bet that the
chances are at least
25% that his RGB setup is such that my file will be
misinterpreted, probably
higher if the stranger is a printer. And in that
case disaster is
guaranteed. Passing LAB instead eliminates the risk.
Why is it, exactly, that the chances his RGB setup is
such that your file would be misinterpreted? For the two reasons I've
already specified: the embedded profile is being ignored and the wrong one
is being assumed, or there is no embedded profile and the wrong one is
being assumed. To avoid disaster requires eliminating the blind use of
assumed source profiles for RGB images.
So speaking of a "Hurt Me" sign - the Off
color management policy being used in cases where people think they are
making themselves immune to color management issues. That's a big ass sign.
The Off policy is a color management automation tool, and so is Convert to
Working RGB/CMYK. Off doesn't mean color management off, it means Ignore
Embedded instead of Preserve Embedded. That's what Adobe should have called
it. Off is improperly named.
The problem is that the Off policy happens to be the
default since the default settings are for Web Graphics. Change them to
U.S. Prepress Defaults, and you get Preserve Embedded Profiles as the
policy. That eliminates the vast majority of problems. The remaining
problems are untagged RGB images and improperly tagged RGB images. There
are a lot more untagged RGB images than there are improperly tagged RGB
images.
The only reason the LAB file works better (as I said)
is because it's implicitly embedded profile can't be ignored. That it also
can't be wrong is trivial because I don't have any reason to believe there
is anything but a trivial number of improperly tagged RGB images until I
hear a compelling argument otherwise.
Chris Murphy
Color Remedies (TM)
www.colorremedies.com/realworldcolor
____________________________________________________________________________
Date: Sat, 15 Feb 2003 18:40:28 -0500
From: John Castronovo
Subject: Re: Best practice for RGB stock images?
From: "Andrew Darlow"
Wouldn't a Macbeth chart or Kodak color wedge(assuming
light was a
consistant temp and even across the art) in each shot
have been even
better?
Sure. Even a simple gray scale would help, but the
attitude, which is supported by many in this group, is that since it's a
digital capture, the numbers speak for themselves. As we know, nothing
could be further from the truth. The photographer even refused to go to the
computer to tell me which RGB space was set up as his default in Photoshop
considering this question an admission of our inability to deal with his
work! In the end, we guessed well and everyone was delighted with the job,
but this kind of b-s is an unreasonable and unnecessary hazard.
john castronovo
____________________________________________________________________________
Date: Sat, 15 Feb 2003 19:02:20 -0500
From: Terry Wyse
Subject: Re: Best practice for RGB stock images?
on 2/15/03 1:54 PM, Dan Margulis wrote:
Nobody was advocating ignoring embedded profiles,
although in fairness, the
proportion of users who tag files correctly is so
infinitesimal that I can
understand why printers do ignore them, and I also
understand why they tend
to view the existence of an embedded profile as a
suggestion that the user is
unskilled.
I'm not sure I understand. Wouldn't you say it's
relatively DIFFICULT to incorrectly tag an image? Offhand, The only way I
can think to do even do this is to PURPOSELY ignore/overwrite an embedded
profile by PURPOSELY assigning a different profile to the image and then
PURPOSELY saving this image with the new/incorrect profile embedded.
Anybody going to this length to do the wrong thing is bent on sabotoging
the image in my view.
Terry
--
__________________________________
WyseConsul
Color Management Consulting
v 704.843.0858
__________________________________
____________________________________________________________________________
Date: Sun, 16 Feb 2003 00:40:58 -0600
From: Ron Bean
Subject: Re: Best practice for RGB stock images?
Ron Kelly writes:
John, I'm not sure this is such a good example; or
maybe, it is. I will
NEVER blindly trust a technology to the extent that a
poodle that looks
pink will pass through my hands untouched, just
because the technology
says that it supposed to look that way!
This is what the contract proof is for-- it gives the
customer a chance to verify that the color is correct (or not).
I get the impression that some people would like to
skip this step, and somehow make sure the color is correct *before* the
customer sees it. Unless you can read the customer's mind, the only way to
do that is to pick up the phone and communicate (as John C mentioned in an
earlier post). I continue to be amazed at the number of people (both
customers and vendors) who don't want to do that.
BTW there was a similar story from the old "Star
Trek" series back in the '60s. They were doing color tests of an alien
woman who was supposed to have green skin, but no matter how green they
made her makeup, she always looked pink on film. Finally they discovered
that the lab was "correcting" the film (nobody told them she
wasn't supposed to be human).
John Castronovo writes:
The photographer even refused to go to the computer to
tell me which
RGB space was set up as his default in Photoshop
considering this question
an admission of our inability to deal with his work!
In the end, we guessed
well and everyone was delighted with the job, but this
kind of b-s is an
unreasonable and unnecessary hazard.
Yeah, the problem isn't the technology-- the problem
is the "let's not communicate" attitude.
____________________________________________________________________________
Date: Sat, 15 Feb 2003 23:03:38 -0800
From: Lee Varis
Subject: Re: Best practice for RGB stock images?
Re: profiles, to Tag or not to Tag...
I think we've gotten past the Photoshop 5 period where
it was easy to embed the wrong profile in an RGB or CMYK file and this
caused huge problems for service bureaus. There are still problems with
various Colorsync workflows but I don't think that's an issue with the
underlying technology (cue Charlton Heston: "Profiles don't kill
people, apes with profiles kill people") The thing is... what do you
do with all those apes ?
As an artist who has to produce work that gets
published in less than ideal circumstances most of the time, I find that
often I'm faced with the challenge of protecting against the assumptions,
right or wrong, of the many people who may get involved with the print
production process. Very often I find two different approaches among the
service people that handle my work:
1. The printer has Photoshop set to a color management
off policy : fine, no problem for me whether I have a profile in the file
or not - it is simply ignored and the file is output as is or pre-flighted
to fit the printers press conditions. I routinely prepare all files
destined for press ready to go as is, already in the specific output space
or, at the very least SWOP, addressable by any print house. This is the
situation the vast majority of the time.
2. The printer has a history with profile f**k ups
such that they now have a policy in place to perform some kind of automatic
"correction" on the assumption that the supplied file is probably
messed up if it has a profile "embedded". "The only good
profile is a dead profile" I have seen shops do the strangest things
to perfectly good files simply because they discovered that there is
"the devil's profile" in them. The only solution here is to ask
enough questions ahead of time to find out if you're dealing with a
"profile-hostile" organization. If you are - don't embed and
proceed as before with a file already prepared for output as SWOP. Most
often, in this scenario, prepare for SWOP even if the shop is doing Flexo
or some other kind of non-standard output. Even CTP outfits generally
assume any CMYK file is set up for SWOP and they have some transform curves
in place to "correct" the file for output. Maybe its not ideal,
but that's they way they do it and there ain't nothing you're going to do
to change it.
Finally, that still leaves the issue of what to do
with those RGB files. If you are faced with submitting RGB files (like for
a stock agency) you have to "trust in Allah... but tie up your
camel"-- embed a profile! I make it a "rigid" policy to
prepare the RGB file in a standard Photoshop workspace such that if some
bozo opens the file, ignores the profile, and selects: Mode->CMYK he'll
have a reasonable chance of getting something useable for SWOP. That means
that whatever workspace I may personally prefer, when I'm done I'm going to
convert to Adobe'98 and tag it that way - but make damn sure that it is
fully within gamut for SWOP CMYK. The funny thing is that I end up very
good images that way.
Now... is this really much different than what might
have been wise before profiles were even discussed in polite company? Not
really, its just that now I have to be extra careful, dot all my i's and
cross my t's and still, at the end of the day, I can't be certain that
anything is going to print right until I've seen some kind of contract
proof.
But I still have hope that one day this will all be
easier...
regards,
Lee Varis
http://www.varis.com
888-964-0024
____________________________________________________________________________
Date: Mon, 17 Feb 2003 00:18:19 -0800
From: "Stephen Marsh"
Subject: Re: Best practice for RGB stock images?
This thread is moving a bit away from the original
series of points into tired old ground, once again.
It has been established that stock images for non ICC
savvy users would probably be best delivered in ColorMatch RGB for Mac or
sRGB for PC users - my bet would be CM RGB if only given one option. Since
RGB is the space in question and this is a master archive image, a profile
somewhere is a very good idea. If a higher gamut file and tag is required
for ICC or more colour savvy users, then this may be marketed as a pro
option as a value added service to the everyday image or whatever. I think
it is safe to say that the original thread has run it's course, although
the originator of the post may want to say something here.
Now we are into more familiar ground with the sparring
between Dan, Andrew and Chris.
As for tags in CMYK files - there are as many pros as
cons. It all depends on the wants, needs and expectations of both image
presenter and the person who happens to be handling the image.
If your workflow is the traditional one where values
matter more than profiles - I still think the best thing to do when finding
a CMYK tag is to ignore it and see how the numbers perform in the expected
presumed output conditions. If it looks poor (we do have an aim print and
are not working blind <g>) then the tag may be used to see if this is
an accurate description of the incoming file and a conversion off the tag
may be helpful - but not as a default practice.
If you rely on ICC tags more so than the files values
and a presumed space - then the tag and conversions will obviously be
critical to your workflow. Untagged files would have no place here and
would be a problem - back to assuming things or guesswork without assuming
a Photoshop LAB file.
I do not see any viable middle ground in a productive
setting. But this is what is currently being asked of many of us, with
clients and SP who ignore, use and misuse ICC methods. I would ideally
choose one workflow or the other and document this for all parties
concerned.
What I find sad is that 'explicit' ICC managed output
workflows are not the traditional way of doing things and users who do not
know or should know better attempt to force this onto users who do not work
that way (for right or wrong).
On the flipside, more basic help could be given to
those performing separations to unfamiliar conditions by those who dictate
those conditions.
There is nothing preventing a user from using CM
internally and handing off a traditional final value file for output. If it
is safe to presume that your ICC intent will be ignored, presumed or
screwed up - only a masochist or a poorly informed user would attempt to go
against the flow and wail that they are dealing with dinosaurs.
I have had many Quark v4 users supply colour managed
files to printers prepress departments (if CM was even installed in Quark,
otherwise we may not even be aware that the incoming file was using CM). I
doubt even the most rabid ICC proponent would expect that a Quark v4 file
using CM from a client sent to a traditional small 'local' printer would
actually work as all parties intend. I doubt these users knew they were
using CM in Quark.
On the wrong profile issue, I have had the opportunity
to work in more shops than I would have personally liked over these last
five years and I think I have a good insight into supplied data from both
image supply and service providers viewpoints. One should not discount
corporate bean counters not updating software, user ignorance and other
issues. Yes, for v6 or higher it is hard to mistag a file. But there is
still a huge amount of Photoshop 4 and 5 print users out there, and those
v5 users will make mistakes whether they like it or not (I know I have,
when the pressure is on one may forget about a colour setting that was
changed for a specific reason on another image but is not required for this
one).
So for RGB, if there is a tag it can't hurt to
potentially see how this translates into your output conditions - or to use
whatever you want to get the job done if that is your workflow (many a time
I have used a 1.8 gamma when the source profile was 2.2 - otherwise mud
would have been the result...visual mud or by the numbers mud).
For CMYK, most users in the know supply final output
ready CMYK and do not want the numbers changed (the K plate is a common
example). A tag may invite the numbers to be changed by intent or human
error, where as no tag will lead to the file simply being opened unaltered
as in legacy workflows. If the files numbers do not represent the actual
output and it is very far removed - then the embedded tag is a good thing
and changing the files numbers is probably the right thing to do...although
you may have to take note of the original K plate and try to pass that onto
the other file in key places if this is a concern (K only linework for
example which should not be four colour).
Chris Murphy writes:
They need to get with the program and have a mechanism
for dealing with
profiles.
How about some balance? Both presenter of work and
service providers have duties and obligations. It is just a matter of
finding out what they are in any given situation.
What seems lacking from these debates is the ability
for those who favour a certain viewpoint to understand and appreciate the
issues that the 'enemy' faces. I have worked in both art studio situations
attempting to hand off art to printers who are not very helpful. I have
also worked for different types of service providers and understand their
viewpoint too, faced with clients of all backgrounds and skills. There is
no easy answer for either party. Communication is the key. Customers have
to ask for published guidelines for dealing with a SP. A service provider
has to have published guidelines for clients to fit into the workflow, or
they have to be willing to deal with whatever is thrown at them to get
work. Both users should be able to meet each other in the middle, or at
least to some sliding extent. <g>
In the good old days results and skills were valued
more so than bottom dollar and one worked with like minded professionals.
It is a very different story today, which is why the industry is all over
the place and it is anyone's guess on how things may be done.
P.S. On the LAB issue - it is not correct to say that
LAB is only a visual safety net, it also locks in colour values from the
original. I could be working on a greyscale monitor on a RGB or CMYK image
- when I move that image to LAB and hand it off to a service provider, I
know that the source values can't be mistaken. What I saw on my monitor
does not enter the equation.
Stephen Marsh.
____________________________________________________________________________
Date: Sun, 16 Feb 2003 10:10:12 -0700
From: Andrew Rodney
Subject: Re: Best practice for RGB stock images?
on 2/15/03 11:40 PM, Ron Bean wrote:
I get the impression that some people would like to
skip this
step, and somehow make sure the color is correct
*before* the
customer sees it.
IF you sell contract proofs, no way. If however you
happen to have to BUY Contract Proofs, why spend the money when you can
simply VIEW the numbers correctly and get a pretty good idea where you
stand. I1m not at all suggesting one forgo a contract proof. I1m suggesting
it1s a huge waste of time and money for a customer who only wants to see
the correct appearance of a file on a calibrated and profiled display.
Unless you can read the customer's mind, the
only way to do that is to pick up the phone and
communicate (as
John C mentioned in an earlier post). I continue to be
amazed at
the number of people (both customers and vendors) who
don't want
to do that.
That1s also a waste of time for lots of work. And
talking about color is about as ambiguous as viewing data in a non color
managed environment. If you get a tagged file which shows a pink dog on
your calibrated and profiled display in Photoshop, you1re seeing what the
customer supplied and expected (assuming they too have a calibrated display
and if not, you can show them exactly what the numbers in the file are
supposed to produce).
BTW there was a similar story from the old "Star
Trek" series
back in the '60s. They were doing color tests of an
alien woman
who was supposed to have green skin, but no matter how
green they
made her makeup, she always looked pink on film.
Finally they
discovered that the lab was "correcting" the
film (nobody told
them she wasn't supposed to be human).
I1m having an interesting off line discussion with an
owner of a color lab doing digital mainly for wedding and portrait
photographers. Their history is to open and 3correct2 the files they get.
They suggest customers tweak their displays to match a reference print they
send (an exercise in futility). When I suggested that with a good output
profile of their device, the LAST thing I ever want is for them to edit my
files, this guy got a bit confused. The last thing most pro1s want is
someone opening their files and editing them without any permission to do
so. Some people do want green alien women. Until Photoshop comes with a
cranial probe for customers and can insert their ideas about color into the
EXIF tag1s of files, profiles work surprisingly well!
____________________________________________________________________________
Date: Sun, 16 Feb 2003 10:30:46 -0700
From: Andrew Rodney
Subject: Re: Re: Best practice for RGB stock images?
on 2/17/03 1:18 AM, Stephen Marsh wrote:
If your workflow is the traditional one where values
matter more than
profiles - I still think the best thing to do when
finding a
CMYK tag is to ignore it and see how the numbers
perform in the expected
presumed output conditions. If it looks poor (we do
have an aim print and
are not working blind <g>) then the tag may be
used to see if this is an
accurate description of the incoming file and a
conversion off the tag may
be helpful - but not as a default practice.
I don1t understand the advantage of simply ignoring a
profile and sending the numbers to an output device to see if it1s 3good2
or not. It1s certainly a great way to work if you SELL output. Otherwise I
don1t see it being very effective.
The file in question is just a set of CMYK numbers.
The profile doesn1t change this. You can decide to simply send the numbers
in question to the output device and be done. IF the client doesn1t like
what he sees, then the question is, what did you expect me to do? I would
think that if the option for the service provider were to simply output
verses correct then output, the service provider would ask before even
opening the file and IF corrections were needed, the final bill would be
higher.
People can supply CMYK with or without a profile. The
numbers are the same. The question should be, what are the expectations of
the customer? IF they supply an untagged CMYK file, it1s just CMYK mystery
meat. As a service provider, you can do the two options above (simply
output the file and client gets what the numbers provide) OR load the house
profile and ask 3Does this look butt ugly and perhaps a call to the
customer is in order. Customer may at this time say 3print a proof2 or
3Correct and print a proof2 and we1re done).
People can supply a file with an embedded profile with
exactly the same numbers. We still don1t really know if customer expects
direct output or view/correct/output. The profile at least shows us what
the intent of the appearance of the file was when custom saw it. It may be
a mile off from our house profile in which we can talk to and charge
customer. Embedded profile also allows us to convert CMYK to CMYK (we
charge) and perhaps correct and proof (we change again). Main difference in
two scenario1s is NOT the numbers in the CMYK file. The difference is a
clue to what customer expected and ability to get to that aim with far less
ambiguity. That1s the key for me, that the profile provides some degree of
expectation of the appearance of the file. The numbers may not be correct
for house output device but at least we have a road map to what customer
saw and getting to house numbers. Anything else is just a convoluted
guessing game and no one has time for that!
Based on conversations with lab owners (traditional
RGB, Photo labs going digital) and CMYK/print/pre-press providers, the
question I think should be addressed is what is expected by the client and
what is expected by the 3lab2. Do we expect to have our files opened and
altered? Do we expect the lab to simply send the numbers to the output
device and client gets what was provided in the first place?
If you rely on ICC tags more so than the files values
and a presumed space -
then the tag and conversions will obviously be
critical to your workflow.
Untagged files would have no place here and would be a
problem - back to
assuming things or guesswork without assuming a
Photoshop LAB file.
Right. Again, the tag is just a label. The numbers are
the numbers.
There is nothing preventing a user from using CM
internally and handing off
a traditional final value file for output.
But do we know the shop will simply send what the user
believes to be the right set of numbers directly to the output device or
edit the numbers because they 3know better2? And if the file is untagged,
even if we knew the customer had their CMS act totally together, do we
wonder about the file1s intent since it1s untagged? It seems like the ideal
workflow would be to allow multiple users to see the same numbers the same
way. If a file comes to us tagged, we assume that the values are where they
need to be. If the output isn1t what the customer wants, the responsibility
should be on the customer unless told specifically that
opening/viewing/altering numbers is an additional service with an
additional cost.
The bottom line is that the numbers are either right
or they are not. Who takes responsibility for this?
Andrew Rodney
____________________________________________________________________________
Date: Sun, 16 Feb 2003 13:27:05 -0500
From: John Castronovo
Subject: Re: Best practice for RGB stock images?
From: "Andrew Rodney"
The last thing most pro1s want is someone
opening their files and
editing them without any permission to do so. Some
people do want green
alien women. Until Photoshop comes with a cranial
probe for customers and
can insert their ideas about color into the EXIF tag1s
of files, profiles
work surprisingly well!
Exactly!
With the exception of wedding & portrait
photographers where the desired color is more or less obvious, this is why
professional photographers have traditionally shot transparency films - to
avoid labs and scanner operators screwing around with their work.
People don't like to scan negatives because it leaves
too much up to interpretation. There's no way to tell if an unknown object
in a negative is white, silver or gold. A transparency is its own proof and
it establishes itself as the final image which must be preserved. Everyone
can agree on the color when it's viewed on a standard D50 light box.
A color managed workflow does the same by setting
viewing standards. It's simple, it works, and the only reason not to use it
appears to be that some people still haven't taken the time to do it. Using
that same logic, we should stop doing most things for lack of education and
cooperation.
john castronovo
____________________________________________________________________________
Date: Sun, 16 Feb 2003 14:22:33 -0700
From: Chris Murphy
Subject: Re: Best practice for RGB stock images?
On Sunday, February 16, 2003, at 12:03 AM, Lee
Varis wrote:
But I still have hope that one day this will all be
easier...
That is one of my biggest hopes for Real World Color
Management. The current version will document most of the issues, and let
people know the dangers of things like "Convert to Working
RGB/CMYK" and "Off." Those are color management automation
mechanisms.
But more importantly I want to see a public dialog on
the remaining problems and what we (the users of color management) should
tell the vendors to do about it. A program that has a printing bug is
probably going to get fixed relatively soon because a lot of people print
things from their apps. If people just try to avoid profiles like the
plague, the remaining problems associated with them will take longer to get
fixed.
Chris Murphy
Color Remedies (TM)
www.colorremedies.com/realworldcolor
____________________________________________________________________________
Date: Sun, 16 Feb 2003 14:59:13 -0700
From: Chris Murphy
Subject: Re: Re: Best practice for RGB stock images?
On Monday, February 17, 2003, at 01:18 AM,
Stephen Marsh wrote:
This thread is moving a bit away from the original
series of points
into tired old ground, once again.
I don't think so. Based on your post, which
encompasses many issues we haven't even talked about yet: color management
in QuarkXPress, and even to some degree embedding profiles in CMYK images.
My point was explicitly in response to Dan's comments about embedded
profiles in RGB images, and that an "infinitesimal" number of RGB
images have the correct profile embedded. The secondary point had to do
with whether LAB images are somehow more safe (and I provided my opinion
why already so I don't need to restate it here). That's all.
Now if we start talking about tags in CMYK profiles,
that's a separate issue and I doubt we'll find much debate there. As I
explained in a previous post, we didn't embed profiles in CMYK images for
Real World Color Management. Everything was produced "press
ready."
I think the issues you raise, about the demands on
service bureaus, printers, and how they related to the extremely wide
assortment of customers they have, is out of scope for this list's charter,
but I'm not the list moderator. I find it to be a fascinating discussion
because it's so complex, and because there are so many issues. Some
critical thinking by industry leaders to attack those issues would likely
be very useful to the industry as a whole.
(And no I definitely do not expect a QuarkXPress 4 or
5 file set to use CM is going to work as all parties intended. Color
management in QuarkXPress is not exchangable between parties. Its system is
designed to be configured and then put to use on a given machine.)
Yes, for v6 or higher it
is hard to mistag a file. But there is still a huge
amount of Photoshop 4
and 5 print users out there, and those v5 users will
make mistakes whether
they like it or not
I agree. Photoshop 4 files are untagged. So they
aren't ever improperly tagged. Photoshop 5 still has the potential to
improperly tag images. But to do so necessitates manipulating color
management features:
1. Do a Profile to Profile, which converts but then
does not assign the destination profile as the new source, rather it
improperly embeds the original source profile. What percent of all
Photoshop 5 users use this feature? And then with what regularity do they
use this feature?
2. Go into Color Settings, RGB Setup or CMYK Setup and
change the settings, thereby changing the "assigned" profile and
subsequently embedded profile for open documents, without having changed
the data. The same questions above apply.
Stephen, do you think remaining Photoshop 5 users are
using either (or both of these features) to even a measurable degree, let
alone a significant one?
How about some balance? Both presenter of work and
service providers have
duties and obligations. It is just a matter of finding
out what they are in
any given situation.
My statement is a general statement that simply
ignoring profiles is tantamount to sabotage. Each organization needs a way
of dealing with profiles based on their workflow and their customers. To
have a single method of dealing with all situations such as "toss the
profile" or possibly worse "convert everything using the embedded
profile" is irresponsible. There is no catch all.
I have previously posted my general list of content
provider responsibilities and printer responsibilities. The bottom line for
any workflow including using color management is verbal or written
communication. Embedding profiles alone is not enough. Expecting document
color management settings to survive transit through a virtual maze of
production is not enough. Color management is quite week on tracking
things. If users #11 in the design or production process changes a setting,
no record of that is kept or as to why. And I don't mean some fancy
hard-core piece of software to do this, but even making a notation on a job
order; or confirming with the customer verbally. But sooo many
organizations do not have such mechanisms in place.
P.S. On the LAB issue - it is not correct to say that
LAB is only a visual
safety net, it also locks in colour values from the
original. I could be
working on a greyscale monitor on a RGB or CMYK image
- when I move that
image to LAB and hand it off to a service provider, I
know that the source
values can't be mistaken. What I saw on my monitor
does not enter the
equation.
I never said it was a visual safety net. I said that
if you're going to trust the display, in either the case of RGB or LAB, you
must have the monitor calibrated/profiled. The implied alternative, which
you mention above, is that you are intimately familiar with the behavior of
the space you are using, and don't need accurate display representation.
(Although, having this familiarity with the space you are using is vastly
easier with RGB, especially a particular kind of RGB, than it is with LAB.)
I also specifically mentioned the advantages of LAB
are: a.) the implicit source profile can't be ignored and b.) the source
profile is always correct. And the situations where RGB images break down
are when source profiles are ignored or profiles aren't embedded.
Chris Murphy
Color Remedies (TM)
www.colorremedies.com/realworldcolor
____________________________________________________________________________
Date: Sun, 16 Feb 2003 20:21:40 EST
From: Dan Margulis
Subject: Re: Best practice for RGB stock images?
Terry writes,
Wouldn't you say it's relatively DIFFICULT to
incorrectly tag an image?
I would agree that it is relatively difficult to
incorrectly tag an image if 1) you are using Photoshop 6 or 7; and 2) you
have not chosen one of several objectionable defaults; and 3) you have a
monitor that is perfectly tuned to contemporary calibrationist standards as
opposed to having been neglected or messed around with to match samples.
For the remaining 99.99% of Photoshop users, it
appears to be relatively easy.
Dan Margulis
____________________________________________________________________________
Date: Sun, 16 Feb 2003 20:21:16 EST
From: Dan Margulis
Subject: Re: Best practice for RGB stock images?
Chris Murphy writes,
To avoid embedding just to prevent someone who doesn't
know what they
are doing down the line from messing up the file isn't
a valid excuse.
They need to get with the program and have a mechanism
for dealing with
profiles.
Ah, yes. Educate the end-user. How oft have we heard
that old, sweet song. Unfortunately, it's been five years since the
noble experiment began, and there is no sign that they are getting better
educated. Meanwhile, they wreck jobs and we are expected to eat the cost.
Thanks, but I've already had enough jobs suffer that fate.
Stephen's and Lee Varis's comments are right on the
mark about the real-world situation. But in the imaginary world envisioned
by the color management community, it doesn't matter how many years go by,
or how many users turn away from the method in disgust after rightly
concluding that it's ineffective and error-prone, or how minuscule the rate
of adoption is. The line will always be the same: we've finally turned the
corner, it's all a matter of educating the users, we're really seeing a big
move toward it now, anybody who doesn't realize this is rigidly stuck in
stupidity.
I also agree with Stephen that this rehash of the same
points, year after year after year, is very tired. The sooner this
thread closes, the better.
Dan Margulis
____________________________________________________________________________
Date: Mon, 17 Feb 2003 01:07:34 -0500
From: John Castronovo
Subject: Re: Best practice for RGB stock images?
From: Dan Margulis
Ah, yes. Educate the end-user. How oft have we heard
that old, sweet song.
Unfortunately, it's been five years since the noble
experiment began, and
there is no sign that they are getting better
educated. Meanwhile, they wreck
jobs and we are expected to eat the cost. Thanks, but
I've already had enough
jobs suffer that fate.
Dan, you have to come up with something better than
saying that end users can't be educated. If they're that dumb that they
can't embed a proper RGB profile for a color working space, then nothing
will get them to hand off jobs properly. Do you actually think that they
can do it by the numbers alone, and as the one who has to print it, can I
trust that file any more? How do I know if those numbers represent sRGB or
DonRGB values? Same numbers yield different results. Who eats the cost if
the job is wrecked because the numbers aren't correct vs. the profile being
incorrect?
john castronovo
____________________________________________________________________________
Date: Mon, 17 Feb 2003 08:59:30 -0000
From: "Stephen Marsh
Subject: Re: Best practice for RGB stock images?
I agree. Photoshop 4 files are untagged. So they
aren't ever improperly
tagged. Photoshop 5 still has the potential to
improperly tag images.
Hi Chris, I originally decided not to count the v4 Mac
users who used the ColorSync read/write plugs. So I guess they should be
considered to keep things accurate. <gEven if there was not that many
actual production uses of them (I remember trying them and not using them
for production, but I can't remember the issues at the time - this was way
before any of the v5 ICC introduction hoohah).
But to do so necessitates manipulating color
management features:
1. Do a Profile to Profile, which converts but then
does not assign the
destination profile as the new source, rather it
improperly embeds the
original source profile. What percent of all Photoshop
5 users use this
feature? And then with what regularity do they use
this feature?
I can't answer that. Most were told by those in the
know to avoid P2P moves as the ICC foundation was not there in v5 to make
it all work in the real world with ease. v5 CM was a great beta - its just
a shame that the public ever saw/used it. v6 CM is fantastic when compared
to v5.
I do use P2P sometimes when in v5.x - For example I
have a little action that converts an untagged original from each of the
four presumed standard RGB WS profiles to the current RGB space (no concern
about wrong profile tagging here) - as both a visual and numbers softproof
evaluation as to a good start point.
Sure, v6 is better, no conversion - you just assign.
Stephen, do you think
remaining Photoshop 5 users are using either (or
both of these features) to even a measurable degree,
let alone a
significant one?
Again I can only really speak for myself.
This is the one that will often burn me. I may dupe a
file and convert it into a different CMYK space and edit in that space for
targeted blending into a file that uses a different profile to describe the
numbers.
Stephen Marsh.
____________________________________________________________________________
Date: Mon, 17 Feb 2003 08:38:00 -0000
From: "Stephen Marsh
Subject: Re: Best practice for RGB stock images?
I don1t understand the advantage of simply ignoring a
profile and sending
the numbers to an output device to see if it1s 3good2
or not. It1s certainly
a great way to work if you SELL output. Otherwise I
don1t see it being very
effective.
I will answer your question with your own words
<g>:
"IF you sell contract proofs, no way. If however
you happen to have to BUY Contract Proofs, why spend the money when you can
simply VIEW the numbers correctly and get a pretty good idea where you
stand."
I should have expanded the original vague point on
what 'seeing things in your conditions' was meaning - I meant softproofing
of the expected conditions. All you have to do is setup a softproof with no
conversion of values - so the raw cmyk numbers end up displayed in the cmyk
house proof profile (for many it is a simple matter of grabbing the CTP
proofing profile - but don't make the mistake of grabbing the inkjet
destination profile, you want the input proofing profile. Those inkjet
values do not work on press. <g>).
Based on conversations with lab owners (traditional
RGB, Photo labs going
digital) and CMYK/print/pre-press providers, the
question I think should be
addressed is what is expected by the client and what
is expected by the
3lab2. Do we expect to have our files opened and
altered?
Not in any CMYK press workflow that I have
encountered. EVER.
Sounds like these photo labs have a totally different
approach to any prepress house I have ever seen or heard of.
Do we expect the
lab to simply send the numbers to the output device
and client gets what was
provided in the first place?
A prepress service provider would not be doing much
work if they decided to make a final files values different without prior
consent - which as I said above I have not come over in press workflows.
But do we know the shop will simply send what the user
believes to be the
right set of numbers directly to the output device
You betcha - see above, otherwise they get no payment
or have to do the job right until my densitometer shows that the control
bars are spot on.
Process control in film repro has always been pretty
good though (in my experience), although I have seen some shocking things
with CTP - dots were all over the shop (but this was not for any valid or
sane reason <g>).
The bottom line is that the numbers are either right
or they are not. Who
takes responsibility for this?
In my little world - if the file is greyscale or CMYK,
then hands off the job is final and wanted as is with no alteration unless
there are explicit instructions.
If RGB/LAB, then the ball is obviously in my court.
It depends on whether you are just using supplied data
as is, or whether you also have the option to make judgement calls about
the colour/tone etc. There may be explicit cases where you are told to
alter a file or where a setting allows this as par for the course - but
usually CMYK is considered locked in unless you know better.
Stephen Marsh.
____________________________________________________________________________
Date: Mon, 17 Feb 2003 08:16:11 -0500
From: John Romano
Subject: Re: Best practice for RGB stock images?
I have been reading this thread far to long and I
agree that embedded profiles either CMYK or RGB is the way to go. If you
are supplying files or recieving them.
Recieving CMYK files with tags has been a GREAT
savings to our press department,before we were into an ICC workflow
supplied images went to press with out custom dot gain
adjustments.Having supplied files with different dot gain and different
separation methods was a real Horror show on press and now everything goes
out with the exact same settings and Life is good in the press room.
We get a fair share of supplied files from all around
the world and we prefere getting them tagged. When we send out CMYK files
we also send an Instruction sheet on how to handle our files and that they
were created in an ICC workflow.
Very basic stuff on how to set up photoshop and
get a good conversion to thier workspace. The last thing on the intruction
sheet is if you have any questions please call. Now if this doesnt work
what will they do ? call and say your files are wrong ? Then you can say
see attached info sheet and you are absolved from "thier"
mistakes.
Rgb images that are mistakenly attached the wrong
profile is only a matter of common sense. if it looks bad, we will assign a
different profile until we see something that looks visually good on
our calibrated and profiled display.
Everyone in that is recieving and sending out images
can certainly afford to get Photoshop and thier monitors set up
properly. Its not rocket science .
just my 2¢ as a printer on the list
John
____________________________________________________________________________
Date: Mon, 17 Feb 2003 09:47:22 -0500
From: John Castronovo
Subject: Re: Re: Best practice for RGB stock images?
From: Stephen Marsh
but usually CMYK is considered locked in unless you
know better.
I'd be comfortable with this were it not for the fact
that after 25 years in the business, I can count on one hand the number of
people who could tell me anything about the printing conditions for this
supposed CMYK file. Even the printers don't know:
"What are you requirements for CMYK?"
"Huh?"
"Do you use profiles?" "What's a
profile?"
"You know. Will this be SWOP?" "Oh.
Yeah, yeah, SWOP."
"How about dot gain?" "Uh, we don't
have dot gain."
"Ok then, what kind of paper or press?"
"I dunno, they haven't decided yet?
Why are you asking all these dumb questions. Look
Buddy, Just gimme a four
color file or I'll tell your customer to go somewhere
else!"
And so it goes.
john castronovo
____________________________________________________________________________
Date: Mon, 17 Feb 2003 08:58:44 -0700
From: Andrew Rodney
Subject: Re: Re: Best practice for RGB stock images?
on 2/17/03 7:47 AM, john c. wrote:
I'd be comfortable with this were it not for the fact
that after 25 years in
the business, I can count on one hand the number of
people who could tell me
anything about the printing conditions for this
supposed CMYK file. Even the
printers don't know:
Isn't that the truth. I call all kinds of shops and
service providers since I have customers that want custom CMYK ICC profiles
generated. When it comes time to pop in all the important settings for a
CMYK profile (boy are RGB profiles easy...), I get some unbelievable
responses on the other end of the line. The one time the shop manager
looked at me in person with a stare of confused expression on his face when
I asked what total ink limits he prints at, I knew I was in trouble. Seems
the drum scan operator who does the night shift usually has the answers
<g>.
Andrew Rodney
____________________________________________________________________________
Date: Mon, 17 Feb 2003 16:19:11 EST
From: Dan Margulis
Subject: Re: Best practice for RGB stock images?
John writes,
If they're that dumb that they can't embed a proper
RGB
profile for a color working space, then nothing will
get them to hand off
jobs properly. Do you actually think that they can do
it by the numbers
alone, and as the one who has to print it, can I trust
that file any more?
Once again, this has nothing to do with my original
post, which stated that I personally do not allow tagged files to fall into
the hands of strangers. You are talking about the case where the tag
has already been put in by somebody else. I have always recommended,
along with every other authority on the subject, that we should take notice
of such a profile and then make an intelligent choice as to whether to use
it or not.
As to the substance of what's above, it's a
simplistic, prehistoric view that has long since been refuted by the
market. It actually antedates Photoshop itself, although it was most common
right after the release of Photoshop 5 in 1998. Many of the features
introduced at that time have proven their utility and have been adopted by
significant numbers of users. Successfully handing tagged files off to
strangers in the context of CMYK output has not. Whether you think this is
stupid or that they can't possibly get good color without it is irrelevant.
All you have to do is look at what happened and you must conclude that they
either have figured out a way to do it or that their standards for quality
are not what you believe. Either way, resurrecting this lame argument on
this list serves no useful purpose. Things have played out the way they did
for a reason. Let's move on.
I echo Stephen's comments about how tired the list is
of threads like this. As it has happened so many times before and has
caused so many negative comments, I would like to point out how it
happened.
*This segment of the thread started by you stating
with respect to printers and prepress houses' color management practices,
"Who has the power to change an industry so rigidly stuck in
stupidity?" and blaming problems on people who don't embed profiles.
*This reminded me of a recent incident where the top
press relations official of a neighboring country called the president of
her country's closest ally a "moron," without checking first to
see whether any reporters were in hearing distance. Some situations
just speak for themselves. I saw no need to respond.
*Another list member nevertheless did respond. Some of
what he said went too far but a lot of it was right on target.
*As usually happens when anyone on the list other than
myself, Stephen or Chris suggests that ICC color management doesn't
guarantee good color, cure cancer or bring peace to the Middle East, he was
immediately set upon by color management vendors and aficionados. A lot of
what was said was correct but there was also needless belittling. Nobody
thought to criticize the original statement that provoked it.
*After I pointed out that I myself don't recommend
handing out tagged files to strangers, this became an occasion for a
lengthy, repetitive general defense of every aspect of color management
*other* than the one I was writing about.
This is an advanced color correction list.
Calibration issues are a matter of concern but they are not our major
focus. And God knows the market penetration of these methods is not such as
to warrant such extended discussion. If you and Andrew wish to continually
congratulate each other publicly on your advanced views, that's very
welcome on the ColorSync list. I again request that this thread end.
Dan Margulis
____________________________________________________________________________
Date: Mon, 17 Feb 2003 18:49:41 -0500
From: John Castronovo
Subject: Re: Best practice for RGB stock images?
I again request that this thread end.
Dan Margulis
AMEN!!
But just before that, I want to explain that my
reference to stupidity was not aimed at you but only those who complain to
me when I ask them about their source profile for RGB images that they send
me.
john castronovo
____________________________________________________________________________
Date: Mon, 17 Feb 2003 22:53:10 EST
From: Dan Margulis
Subject: Re: Best practice for RGB stock images?
John writes,
I want to explain that my reference to stupidity was
not aimed at you but
only those who complain to me when I ask them about
their source profile for
RGB images that they send me.
Noted and appreciated. Thanks for the clarification.
Dan Margulis
____________________________________________________________________________
Date: Thu, 27 Feb 2003 19:09:25 -0500
From: Dan Margulis
Subject: Re: Best practice for RGB stock images?
Folks,
As most of you know, last week I requested that this
long thread close, in view of excessive heat, little light, and repetition
of the same points over and over. Since that time, I have rejected posts
from those wishing to continue it.
Yesterday the following message came in. While I did
not approve it at the time, because it contains an apology from one of the
participants I believe it is appropriate that the list see it. This does
NOT constitute a reopening of the thread; further commentary will not be
approved.
Dan Margulis
*************************************************
From: Jono Moore
Date: WedÊFebÊ26,Ê2003Ê6:56pm
Subject: Re: [colortheory] Best practice for RGB stock
images?
I know this thread is dead now but I figured I should
add a comment to what
I started. :-) Unfortunately I only get a chance
to catch up on messages in
here every week or two.
My post was rather reactionary and I apologize for
that, I realised after I
sent the email that I should have waited til the next
day to rewrite it.
Dan, rather succinctly, summed up my thoughts:
> Jono wasn't talking about his own personal
settings or how to calibrate his
> own devices. He was speaking of the viability of
using profiles to
> interchange documents with total strangers. In
that limited area, he's right:
> printers and SBs have concluded, quite rightly in
my view, that this is an
> ineffective, costly, and error-prone way to do
things. And in any event there
> are so few clients who know what they're doing
with embedded profiles that
> the printers feel little need to pay attention.
--
Jono Moore
udoprinting.com
Note: despite the acrimonious "ending "of
this thread, the topic resurfaced four months later, when I received a
plaintive off-line plea from a person whose file had been ruined when a
printer had not honored an embedded RGB profile. See the "Who’s
to Blame"thread in this section--DM
Adobe Photoshop training classes are taught in the US by Sterling Ledet & Associates, Inc.