Dan Margulis Applied Color Theory
A Few Statements to Validate
Date: Tue, 01 Mar 2005 12:29:57 -0500
From: Martin Benoit
Subject: A few statements to validate
Hello,
My name is Martin Benoit and I teach in a 3-year
photography program in Montreal, Quebec, Canada.
I would like to check with you that these concepts are
not too off-track before I pass them on to my students. Keep in mind that
the students are photographers.
Here are the statements :
1-As photographers, if your clients insist on receiving
CMYK files instead of RGB, give them CMYK files separated according to U.S.
Web Coated (SWOP) v2 unless they specify the separation parameters.
2-If you have to shoot .jpg 8 bits/channel, use sRGB
color space instead of Adobe 98. Since the space is smaller and your depth
is shallower, the increments between each color step will be smaller, and
you will diminish banding throughout the process even if you feel that you
are sacrificing color gamut. Anyway, most printing situations cannot
exploit the wide gamut of Adobe 98.
3-Try to work in RGB as much as possible. Give RGB
files to your client instead of CMYK. It is the prepress people who really
know how to convert to CMYK because it is their field, and they are the one
who really know how the files will be used.
4-When computing the resolution needed for a specific
job, you can still use the 1.3 factor instead of the 2.0 factor to
determine the ppi of your file. (lpi x 1.3 = ppi of your file for lpi
>133).
5-Do not over-sharpen your files. Leave that job to the
prepress people, who know how much sharpening will do a good job for their
setup and the final magnification and lpi.
6-Ask your client for the final output (press) icc
profile to be able to preview the final appearance of your image in
Photoshop . If the client cannot provide you with the profile or doesnxt
know what you're talking about,preview in CMYK U.S Web Coated (SWOP) v2.
7-In North America the norm is still D55 in the viewing
booth, but may shift soon to D65.
8-On the other hand, people tend to set their monitor
to 6500K, gamma 2.2.
9-Adobe98 is the preferred color space as a
general-purpose color space When you donxt know the requirements of your
client, but use it only if you Shoot in Adobe98. Do not shoot in sRGB and
then convert to Adobe98 to please Your client, because in that conversion
you will lose more than if you keep SRGB as the final space.
10-Try to shoot in 16 bits/channel. Keep your files in
16 bits for as long as you can, and do the conversion to 8 bits as late as
possible, or even let your client do it.
Thank you for your concern
Martin Benoit
Dep't of photography
CEGEP du Vieux-Montreal
___________________________________________________________________________
Date: Tue, 01 Mar 2005 12:56:55 -0600
From: Jim Bean
Subject: Re: A few statements to validate
hello martin, if you were to provide the cmyk files and
you deferred the sharpening to the prepress people.. very likely it would
never get done.. correctly. Depending on the image (and how many)
there are basic strategies that target the areas that demand sharpening.
.
never would I have believed that hammering the k plate
(as aggressively as dan m demonstrates) would greatly improve those printed
images.. It works, strategic sharpening is a requirment, not an
option. you might consider spending a few lessons on those
techniques. Quality sharpening techniques separates the good from the
better. all the best, jim bean
___________________________________________________________________________
Date: Tue, 01 Mar 2005 11:46:26 -0700
From: Andrew Rodney
Subject: Re: A few statements to validate
On 3/1/05 10:29 AM, "Martin Benoit" wrote:
1-As photographers, if your clients insist on receiving
CMYK files
instead of RGB, give them CMYK files separated
according to U.S. Web Coated
(SWOP) v2 unless they specify the separation
parameters.
ONLY if that is how the press behaves (as U.S. Web
Coated (SWOP) v2 which is based on TR001 definition of SWOP). If not, all
bets are off.
2-If you have to shoot .jpg 8 bits/channel, use sRGB
color space instead of
Adobe 98. Since the space is smaller and your depth is
shallower, the
increments between each color step will be smaller, and
you will diminish
banding throughout the process even if you feel that
you are sacrificing
color gamut. Anyway, most printing situations cannot
exploit the wide gamut
of Adobe 98.
Well sure, all youxve said is true expect the part
about most printing situations cannot exploit Adobe RGB (1998). SWOP
(specifically U.S. Web Coated (SWOP) is wider then sRGB but fully contained
in Adobe RGB (1998). If saturated greens and cyans are important to you,
youxd be able to output those colors in Adobe RGB (1998) to U.S. Web Coated
(SWOP) v2 and not using sRGB to U.S. Web Coated (SWOP).
3-Try to work in RGB as much as possible. Give RGB
files to your client
instead of CMYK. It is the prepress people who really
know how to
convert to CMYK because it is their field, and they are
the one who really
know how the files will be used.
Big IF. Ixd ask your clients to sign off on some paper
work that the RGB data youxre providing is good and that anything that
happens after that (like a really poor CMYK conversion) isnxt your problem
nor will you be held responsible if something goes wrong. Itxs real easy to
hose data after providing an RGB file and I donxt see why you should be
held responsible.
4-When computing the resolution needed for a specific
job, you can still use
the 1.3 factor instead of the 2.0 factor to determine
the ppi of your file.
(lpi x 1.3 = ppi of your file for lpi >133).
I personally use 1.5 over 133lpi.
5-Do not over-sharpen your files. Leave that job to the
prepress people, who
know how much sharpening will do a good job for their
setup and the final
magnification and lpi.
Again, it depends on the skill of the person doing the
sharpening which should be done at output rez, based on output device and
image content. I would say itxs better to under sharpen then over sharpen.
You might want to read this:
http://www.pixelgenius.com/sharpener/why.html
6-Ask your client for the final output (press) icc
profile to be able to
preview the final appearance of your image in Photoshop
. If the client
cannot provide you with the profile or doesnxt know
what you're talking
about,preview in CMYK U.S Web Coated (SWOP) v2.
Same issues as #1 above.
7-In North America the norm is still D55 in the viewing
booth, but may
shift soon to D65.
D50 although no light box produces this.
9-Adobe98 is the preferred color space as a
general-purpose color space
When you don't know the requirements of your client,
but use it only if you
Shoot in Adobe98. Do not shoot in sRGB and then convert
to Adobe98 to please
Your client, because in that conversion you will lose
more than if you keep
SRGB as the final space.
Shooting in sRGB and converting to Adobe buys you
nothing unless youxre pasting that data into another document that is in
Adobe RGB (1998).
Ixd say shoot RAW, decide how you want to render and
then encode the data into a color working space. These are two separate
processes. The rendering from RAW to say sRGB or Adobe RGB (1998) done in
camera is totally a process based on how the manufacturer of the camera
feels they are producing pleasing color. Itxs totally ambiguous, much like
the Perceptual rendering intent in output profiles (the encoding into the
color space after rendering is standard and non ambiguous).
10-Try to shoot in 16 bits/channel. Keep your files in
16 bits for as
long as you can, and do the conversion to 8 bits as
late as possible,
or even let your client do it.
Sure if the file size/workflow doesnxt become a factor.
IF you ask the camera to do the internal rendering and encoding, you get
8-bit color! If you ask for RAW, youxll usually have control over the
rendering, what working space you want to encode that into AND end up with
more then 8-bit per color data.
Andrew Rodney
http://digitaldog.net/
___________________________________________________________________________
Date: Tue, 1 Mar 2005 12:26:55 -0700
From: Ron Kelly
Subject: Re: A few statements to validate
Martin:
As you would expect, there are some I would agree with,
and some not.
1-As photographers, if your clients insist on
receiving CMYK files
instead of RGB, give them CMYK files separated
according to U.S. Web Coated
(SWOP) v2 unless they specify the separation
parameters.
FIne.
2-If you have to shoot .jpg 8 bits/channel, use
sRGB color space instead of
Adobe 98. Since the space is smaller and your
depth is shallower, the
increments between each color step will be
smaller, and you will diminish
banding throughout the process even if you feel
that you are sacrificing
color gamut. Anyway, most printing situations
cannot exploit the wide gamut
of Adobe 98.
Sure.
3-Try to work in RGB as much as possible. Give
RGB files to your client
instead of CMYK. It is the prepress people who
really know how to
convert to CMYK because it is their field, and
they are the one who really
know how the files will be used.
Depends; don't assume that you are handing things off
to an expert.
4-When computing the resolution needed for a
specific job, you can still use
the 1.3 factor instead of the 2.0 factor to
determine the ppi of your file.
(lpi x 1.3 = ppi of your file for lpi >133).
Also depends; but nothing is so common as excessive
resolution.
5-Do not over-sharpen your files. Leave that job
to the prepress people, who
know how much sharpening will do a good job for
their setup and the final
magnification and lpi.
Yes, if you ask them to do it and they are good. As
before, don't assume that you are handing things to an expert.
6-Ask your client for the final output (press)
icc profile to be able to
preview the final appearance of your image in
Photoshop . If the client
cannot provide you with the profile or doesnxt
know what you're talking
about,preview in CMYK U.S Web Coated (SWOP) v2.
Yes.
7-In North America the norm is still D55 in the
viewing booth, but may
shift soon to D65.
Can't say.
8-On the other hand, people tend to set their
monitor to 6500K, gamma
2.2.
Don't know.
9-Adobe98 is the preferred color space as a
general-purpose color space
When you donxt know the requirements of your
client, but use it only if you
Shoot in Adobe98. Do not shoot in sRGB and then
convert to Adobe98 to please
Your client, because in that conversion you will
lose more than if you keep
SRGB as the final space.
Probably.
10-Try to shoot in 16 bits/channel. Keep your
files in 16 bits for as
long as you can, and do the conversion to 8 bits
as late as possible,
or even let your client do it.
Nope. 16bits/channel is likely to be a complete waste
of bandwidth and time. There *MAY* be circumstances where it is worth it,
but they are very few and/or unproven to exist.
Ron Kelly
___________________________________________________________________________
Date: Tue, 1 Mar 2005 22:32:44 EST
From: Dan Margulis
Subject: Re: A few statements to validate
The students need to be aware that this is a dynamic
field that requires thinking for themselves. By all means present the
concepts, but you need to point out that there is no consensus on most of
them.
It's surprising, in a way, that such simple-sounding
things would be controversial, but I think that there would be differing
expert opinions on eight of these ten questions. (The only ones that I
would expect consensus on are #6, with which I think everyone would agree,
and #7, which, unless there is some trend in lighting booths that I'm
unaware of, everyone would disagree with.)
Personally, I agree with three of your ten statements,
I agree with two others with reservations, I disagree with four and
disagree with one with reservations. Other people would reach different
conclusions.
However, we are speaking only in broad generalities,
about people of whom we know no more than that they are beginning
photographers. As we know more about the individual, the recommendations
might change
So, while it's OK to present your recommendations
(provided that you stress that they are *your* recommendations, which may
not agree with those of other people) you need to stress that unless the
students are able to recognize situations in which those recommendations
become questionable, they will find themselves joining the ranks of the
many photographers who hung their hats on various nostrums without knowing
what they really meant, and got left behind by the advance of understanding
in the field.
Dan Margulis
___________________________________________________________________________
Date: Tue, 1 Mar 2005 22:10:35 -0800
From: "Darren & Leanne
Bernaerdt"
Subject: RE: A few statements to validate
Martin,
I'd like to add my two cents to this as I get the
opportunity to teach photography & Photoshop at one of our local
colleges, shoot professionally and also do a lot color correction for
images destined for print.
1-As photographers, if your clients insist on receiving
CMYK files
instead of RGB, give them CMYK files separated
according to U.S. Web Coated
(SWOP) v2 unless they specify the separation
parameters.
I believe it's better to hand off a CMYK file that has
been converted to a common flavor of CMYK that every version of Photoshop
ships with, than to throw up your hands in despair if you can't obtain a
custom ICC profile from your printer. Here on the Westcoast of Canada I
have run across very, very few printers that can supply a CMYK profile to
be used for RGB to CMYK conversions. Given the variability that's possible
on press, I'd rather make educated decisions about the printing conditions
after a discussion with whomever can supply as much relevant information as
possible about how the job will be printed. I will then use the (admitted
ancient) Custom CMYK option in the Color Settings dialogue box in
Photoshop.
2-If you have to shoot .jpg 8 bits/channel, use sRGB
color space instead of
Adobe 98. Since the space is smaller and your depth is
shallower, the
increments between each color step will be smaller, and
you will diminish
banding throughout the process even if you feel that
you are sacrificing
color gamut. Anyway, most printing situations cannot
exploit the wide gamut
of Adobe 98.
I believe that there are not a lot of naturally
occurring colors outside the sRGB gamut, however this really depends on
what you're shooting. Coming from a decade of medium format digital back
experience, I'm a firm believer in shooting raw.
3-Try to work in RGB as much as possible. Give RGB
files to your client
instead of CMYK. It is the prepress people who really
know how to
convert to CMYK because it is their field, and they are
the one who really
know how the files will be used.
Sure, if your files are going to be posted on the Web.
My experience has been that I (especially as the photographer) am in a much
better position to make the conversion to CMYK and manage those colors that
are out of gamut, shape that needs to be re-built, etc. Give your students
the education on working in CMYK and they will turn out better files, plus
be able to bill for an additional service. For those service
bureaus/printers/EPP depts. that take great care in the conversions - thank
you. I wish there were more of you in the world.
4-When computing the resolution needed for a specific
job, you can still
use the 1.3 factor instead of the 2.0 factor to
determine the ppi of your
file. (lpi x 1.3 = ppi of your file for lpi >133).
Depends on the subject matter and screening
(conventional versus stochastic). This could work fine, however what do you
do with those folk who demand 300ppi images no matter how the job is being
printed?
5-Do not over-sharpen your files. Leave that job to the
prepress people,
who know how much sharpening will do a good job for
their setup and the
final magnification and lpi.
You're setting yourself up for a big fall if you are
not able to guarantee that they will actually look at your file. Who pays
the bill for the proofs that are run straight out from your files when the
client doesn't like the soft images?
6-Ask your client for the final output (press) icc
profile to be able to
preview the final appearance of your image in Photoshop
. If the client
cannot provide you with the profile or doesnxt know
what you're talking
about,preview in CMYK U.S Web Coated (SWOP) v2.
See ques 1. If your job isn't SWOP conditions (ie, on
newsprint or sheetfed), then this is not appropriate.
7-In North America the norm is still D55 in the viewing
booth, but may
shift soon to D65.
Don't know what the trends are in this area. I believe
you are more likely to find a 5000K light source than true D50 conditions.
8-On the other hand, people tend to set their monitor
to 6500K, gamma
2.2.
Sure, except if you're dealing with a traditional Mac
user that still uses a 1.8 gamma.
9-Adobe98 is the preferred color space as a
general-purpose color space
when you donxt know the requirements of your client,
but use it only if you
shoot in Adobe98. Do not shoot in sRGB and then convert
to Adobe98 to
please your client, because in that conversion you will
lose more than if
you keep SRGB as the final space.
I think I understand your question correctly - yes,
shooting in sRGB and converting to AdobeRGB gains you nothing. As to the
flavor of RGB that you choose to work in and what you supply, there are a
great many sources of opinion out there. This topic has been debated on
this list ad nauseum. My personal workflow is based upon ColorMatch RGB,
FWIW.
10-Try to shoot in 16 bits/channel. Keep your files in
16 bits for as
long as you can, and do the conversion to 8 bits as
late as possible,
or even let your client do it.
Without igniting the whole 16 bit versus 8 bit argument
again, I'll just say that shooting in high bit (ie, a raw file) is a great
way to go. How long you want to carry that 16 bit down the pipe is your
choice. It looks like doing the 16 bit to 8 bit conversion in Photoshop
often outperforms the conversion in the camera manufacturer's software.
Leaving the conversion to your client is just one more thing that can get
forgotten in production. Supply 8 bit.
Darren Bernaerdt
___________________________________________________________________________
Date: Wed, 02 Mar 2005 07:09:58 -0700
From: Andrew Rodney
Subject: Re: A few statements to validate
On 3/1/05 11:10 PM, "Darren & Leanne
Bernaerdt" wrote:
I believe that there are not a lot of naturally
occurring colors outside the
sRGB gamut, however this really depends on what you're
shooting. Coming from
a decade of medium format digital back experience, I'm
a firm believer in
shooting raw.
Actually there are LOTS of naturally occurring colors
outside of sRGB. If you shoot RAW and have a good converter like Adobe
Camera RAW, just shoot something like a Macbeth DC or SG color checker and
look at the histogram in sRGB versus other working space. I routinely find
images that I need to convert into ProPhoto RGB because the scene contains
colors outside of even Adobe RGB (1998). This is nicely illustrated with
each color that clips in the ACR histogram. Toggle the working space and
you1ll see this. Keep in mind what sRGB really is. It1s an encoding space
and a working space based on the specific behaviors of a CRT display down
to the phosphors, gamma, chromaticity and even ambient light in which this
display is producing color. The sRGB color space IS a specific description
of a specific display. There are lots of output devices (print and now
display) that produce some ranges of hue that fall outside sRGB in a big
way!
Don't know what the trends are in this area. I believe
you are more likely
to find a 5000K light source than true D50 conditions.
The light box has a correlated color temperature of
5000K. Then there1s the spiky spectral response of Fluorescent tubes (low
Color Rendering Index if you put faith in the CIE1s measure of color
quality).
Sure, except if you're dealing with a traditional Mac
user that still uses a
1.8 gamma.
Actually not. There1s no reason to set a display to a
1.8 TRC gamma. The native gamma of the CRT is very close to 2.2. There1s no
difference between a CRT for a Mac or a CRT for a PC. The Operating system
is assuming a 1.8 TRC Gamma on the Mac (which is dumb and was placed there
for legacy reasons dating back to the LaswerWriter). The best TRC gamma is
the native gamma. If you have say a Sony Artisan, you can actually measure
and hit that exact value. Otherwise guessing 2.2 is far closer to the
native gamma of the display. Why use native? Because any adjustments past
the native behavior of the display has to be conducted at the video card on
8bit data and you introduce banding (display banding, not image banding).
Mac users should calibrate to a TRC gamma of 2.2. Outside smart ICC aware
applications like Photoshop, things will appear a bit dark. In ICC aware
applications, they will not only appear fine but provide a smoother display
of images due to the lack of adjustment at the video card level. Apple
should have killed this 1.8 legacy with OS X but were under pressure to
keep things 3backward compatible".
Andrew Rodney
http://digitaldog.net/
___________________________________________________________________________
Date: Wed, 2 Mar 2005 10:45:06 -0700
From: Chris Murphy
Subject: Re: A few statements to validate
1-As photographers, if your clients insist on receiving
CMYK files
instead of RGB, give them CMYK files separated
according to U.S. Web Coated
(SWOP) v2 unless they specify the separation
parameters.
For first and possibly second year students, sure why
not. But I think it's useful to introduce 3rd year students to more
sophisticated techniques in order to make them more competitive in a
hostile market. At least offer a more advanced course as an option.
2-If you have to shoot .jpg 8 bits/channel, use sRGB
color space instead of
Adobe 98. Since the space is smaller and your depth is
shallower, the
increments between each color step will be smaller, and
you will diminish
banding throughout the process even if you feel that
you are sacrificing
color gamut. Anyway, most printing situations cannot
exploit the wide gamut
of Adobe 98.
The recommendation of space has more to do with the
kind of photography, due to the implied final destination. Adobe RGB (1998)
vs. sRGB isn't going to add up to noticeable banding except perhaps in
extreme situations. A better reason for using sRGB for the uninitiated, is
that there is less propensity for sRGB blues to head toward purplish blue
than Adobe RGB (1998) blues.
Wedding and portrait photographers will be best served
from a simple point of view to use sRGB because there are so many labs they
will be sending their images to that always assume sRGB. Fine art
photographers will likely be better served with a class spending some time
on Camera RAW, and the pros and cons of RAW capture, processing and
archiving. You've got three years, and this is important enough to go into
a three year program at some point.
3-Try to work in RGB as much as possible. Give RGB
files to your client
instead of CMYK. It is the prepress people who really
know how to
convert to CMYK because it is their field, and they are
the one who really
know how the files will be used.
Don't forget to embed RGB profiles, and have explicit
conversations with the hand off person what the expectation is: that the
embedded profile be honored as source when converting to CMYK.
All photographers need to be aware of CMYK conversions,
and what happens to their images both in terms of color shift, saturation
loss, detail loss, and smoothing (lack of content and destination specific
sharpening). They will have to make their own choices as to how much they
care about the appearance of their images once they are transferred to the
client. Some photographers will rightly choose to preserve the
"look" of their work, and have a right to prevent crappy
reproduction of their work. Others won't care, but they need the
information so they can see all sides of the issue.
4-When computing the resolution needed for a specific
job, you can still use
the 1.3 factor instead of the 2.0 factor to determine
the ppi of your file.
(lpi x 1.3 = ppi of your file for lpi >133).
I've never heard of the 1.3 rule. It's generally 1.5 to
2 x lpi, except with images that have a lot of fine, intricate detail and
sharp edges - you might need far higher of a factor than this.
5-Do not over-sharpen your files. Leave that job to the
prepress people, who
know how much sharpening will do a good job for their
setup and the final
magnification and lpi.
That's passing the buck. Photographers need to know
good sharpening technique for various kinds of output. Right or wrong, they
are a lab, and they need to provide their imagery with a conservative
amount of sharpening at a minimum. Better, is to have a conversation with
the customer in advance and find out what sharpening technique they use. If
it sounds adequate, leave it to them. Otherwise the photographer should do
it. It's his work, and how it reproduces will reflect infinitely more on
him than on some obscure prepress guy in a basement in Jersey.
6-Ask your client for the final output (press) icc
profile to be able to
preview the final appearance of your image in Photoshop
. If the client
cannot provide you with the profile or doesn’t
know what you're talking
about,preview in CMYK U.S Web Coated (SWOP) v2.
I'll buy that.
7-In North America the norm is still D55 in the viewing
booth, but may
shift soon to D65.
It's D50 and there's no reason to believe it will be
going to D65.
8-On the other hand, people tend to set their monitor
to 6500K, gamma
2.2.
Sure, but you should tell them why.
9-Adobe98 is the preferred color space as a
general-purpose color space
When you don’t know the requirements of your
client, but use it only if you
Shoot in Adobe98. Do not shoot in sRGB and then convert
to Adobe98 to please
Your client, because in that conversion you will lose
more than if you keep
SRGB as the final space.
The loss is minimal in converting from sRGB to Adobe
RGB. But if a client is going to insist on that, it's a red flag because
there is no advantage to doing this. And I'd disagree that it's preferred
as a general purpose color space. I don't think you'd find a consensus on
this. It's going to depend on the recipient of the work.
Come to think of it, a GREAT class would be called
"Red Flag." And it would be an entire semester on how to defend
yourself, as a photograph, against a world out to sabotage your work. Color
management is only one aspect that can be included.
10-Try to shoot in 16 bits/channel. Keep your files in
16 bits for as
long as you can, and do the conversion to 8 bits as
late as possible,
or even let your client do it.
I'd hand over a 16bpc file only slightly more eagerly
as I'd hand over a RAW file. Capturing JPEG usually implies capturing 8bpc
and capturing RAW implies high-bit (necessitating 16bpc). Again it depends
on the situation. There are legitimate reasons for capturing 8bpc JPEG, and
likewise for RAW or TIFF.
Chris Murphy
Color Remedies (TM)
www.colorremedies.com/realworldcolor
___________________________________________________________________________
Date: Wed, 2 Mar 2005 11:54:36 -0500
From: Brian Pylant
Subject: RE: A few statements to validate
4-When computing the resolution needed for a specific
job, you can still use
the 1.3 factor instead of the 2.0 factor to determine
the ppi of your file.
(lpi x 1.3 = ppi of your file for lpi >133).
Actually, isn't 1.414~ (the square root of 2) the
actual mathematical minimum for calculating resolution for a given
linescreen? The common misconception of cource is that it *must* be twice
the lpi, and others just use 300ppi blindly for all output scenarios, but
I've personally never heard anyone say 1.3 before.
BRIAN PYLANT
Manager, Electronic Prepress
::::::::::::::::::::::::::::::::::::::::::::::::::::::::
::::::::::::::::::::::::
Disc Makers
7905 North Route 130 * Pennsauken NJ * 08110-1402
___________________________________________________________________________
Date: Wed, 2 Mar 2005 11:56:29 -0800
From: Richard Chang
Subject: statements to validate
Darren Bernaerdt wrote:
I believe it's better to hand off a CMYK file that has
been converted to a
common flavor of CMYK that every version of Photoshop
ships with, than to
throw up your hands in despair if you can't obtain a
custom ICC profile from
your printer
Not to mention that a school environment that teaches
craftsmanship is of considerable value. Craftsmanship isn't clicking
a button and saving a file. It's choosing the best CMYK build for the
target, then verifying that highlight and shadow are correct, that neutrals
are neutral, and that skintone ratios are reasonable. There is both
art and science in the making of CMYK, very much like in the making of an
expressive photograph.
I'd like to think that a photo student would learn the
value of a sketal black plate in addition to the value of a stronger medium
GCR for neutrality. If we don't teach our students these principles,
who will?
Richard Chang
www.transitionoftone.com
___________________________________________________________________________
Date: Wed, 2 Mar 2005 12:55:13 -0800
From: Dennis Dunbar
Subject: Re: statements to validate
Dan makes a very good point here. There is a growing
momentum towards building some semblance of a consensus on many of these
points, but it's still in the beginning stages. Until there is a greater
consensus education on the critical issues is more important than ever.
(And perhaps even AFTER there is a consensus, if that ever comes to be.)
Dennis Dunbar
___________________________________________________________________________
Date: Wed, 02 Mar 2005 14:57:29 -0800
From: J Walton
Subject: Twice the linescreen
Any of these automatic linescreen equations fall flat
on their face if you look at enough images. 2x, 1.414x, 1.5x,
1.3x...it1s still trying to put a mathematical equation on some that is
inherently subjective.
I1ve seen plenty of images that needed WAY more than 2x
the linescreen (small images with important fine detail), and plenty of
images that needed WAY less (clouds).
I wouldn1t teach your students that a linescreen
equation is a replacement for experience - it1s just not an exact science.
J
___________________________________________________________________________
Date: Wed, 02 Mar 2005 12:51:33 -0500
From: Dolores Kaufman
Subject: Re: A few statements to validate
Hi Andrew,
Would this also be true for an Apple Studio Display?
Mine is about 5 years
old.
Thanks,
Dolores
___________________________________________________________________________
Date: Wed, 2 Mar 2005 11:20:00 -0600
From: "R. Lutz"
Subject: Re: A few statements to validate
Hi Martin,
You might like to explore with your students, the
benefits of working with RAW captures. Bruce Fraser wrote a very useful
book on this subject --Real World Camera Raw with Adobe Photoshop CS. The
book is about 200 pages and I would credit it with doubling my
effectiveness when using Adobe's Camera Raw features in Photoshop CS.
R. Lutz
___________________________________________________________________________
Date: Wed, 02 Mar 2005 16:38:46 -0700
From: Andrew Rodney
Subject: Re: A few statements to validate
On 3/2/05 10:51 AM, "Dolores Kaufman"
wrote:
Would this also be true for an Apple Studio Display?
Mine is about 5 years
old.
Absolutely!
Andrew Rodney
http://digitaldog.net/
___________________________________________________________________________
Date: Wed, 2 Mar 2005 21:29:20 -0800
From: "Darren & Leanne
Bernaerdt"
Subject: RE: A few statements to validate
From: Andrew Rodney
Actually there are LOTS of naturally occurring colors
outside of sRGB. If
you shoot RAW and have a good converter like Adobe
Camera RAW, just shoot
something like a Macbeth DC or SG color checker and
look at the histogram in
sRGB versus other working space. I routinely find
images that I need to
convert into ProPhoto RGB because the scene contains
colors outside of even
Adobe RGB (1998). This is nicely illustrated with each
color that clips in
the ACR histogram.
Andrew - OK, so we have a couple of monitors that
approach the AdobeRGB gamut. 99.99% of users are not using such a device.
While I'll buy the argument that there is clipping on the histogram in a
smaller space, how do we edit (visualize on screen) a color that can not be
displayed? I've yet to encounter a printer profile that even begins to
approach the gamut of ProPhoto RGB. I would dearly like to vastly expand
the range of color that I can reproduce - can you recommend some printers
that approach the gamut of ProPhoto RGB?
Actually not. There1s no reason to set a display to a
1.8 TRC gamma. The
native gamma of the CRT is very close to 2.2. There1s
no difference between
a CRT for a Mac or a CRT for a PC. The Operating system
is assuming a 1.8
TRC Gamma on the Mac (which is dumb and was placed
there for legacy reasons
dating back to the LaswerWriter). The best TRC gamma is
the native gamma. If
you have say a Sony Artisan, you can actually measure
and hit that exact
value. Otherwise guessing 2.2 is far closer to the
native gamma of the
display. Why use native? Because any adjustments past
the native behavior of
the display has to be conducted at the video card on
8bit data and you
introduce banding (display banding, not image banding).
Mac users should
calibrate to a TRC gamma of 2.2. Outside smart ICC
aware applications like
Photoshop, things will appear a bit dark. In ICC aware
applications, they
will not only appear fine but provide a smoother
display of images due to
the lack of adjustment at the video card level. Apple
should have killed
this 1.8 legacy with OS X but were under pressure to
keep things 3backward
compatible".
Andrew - I think you missed my point. I'm not
advocating setting a gamma of 1.8. I'm simply stating that in the past, it
has been drilled into Mac users heads that 1.8 was the appropriate choice.
Yes, it’s a holdover from the old days.
Since this is offered in the monitor profiling packages
that I've looked at, don't you think that it's likely these users are still
choosing 1.8 because of historical advice? Sure, 2.2 or native is better,
but what do you do in the real world when your client has set 1.8 and
complains your images are dark?
I'd like to inform my students what is best, but also
help them understand the realities that they may be confronted with.
Hopefully they leave the college setting able to deliver a better product
and armed with the knowledge to troubleshoot those situations that go
sideways. (Like the client that has set a 1.8 gamma.)
Darren Bernaerdt
___________________________________________________________________________
Date: Thu, 03 Mar 2005 09:40:45 +0000
From: Martin Bailey
Subject: RE: A few statements to validate
I've seen a lot of different theoretical mathematical
discussions of minimum useful resolution compared to line screen, and
finally concluded that nobody really knows why and how all this stuff
works, especially when you build in the differences between various kinds
of screening. Much of the theory assumes conventional AM screening, and
even assumes that every halftone cell is uniform. Many RIPs produce
"contoured" dots, where you'll see variation of dot size within a
single halftone cell if there are different tone values from the image
data, which tends to cause the theory to break down.
I'd much prefer to go with pragmatic experience in
determining minimum image resolution. I'm not working day-to-day in
production, but what I've seen indicates that 2x lpi is good at low screen
frequencies, but that as the lpi rises the ratio can drop. If you're
running extreme lpi line screens (over 300 lpi, for instance) then just
over 1:1 is fine (remember that Faust managed to print a job at over 1000
lpi (sic)!)
But the resolution you need is also image-dependent. A
sharp image with fine detail, especially fine diagonal rules (including
resolvable hair strands) requires a much higher resolution than a
soft-focus image.
And finally, it's also media-dependent. Print on toilet
paper (or newsprint) and you can get away with a lower ratio than for
coated stock, for instance.
I guess that didn't give a nice, simple rule of thumb
to tell people, did it? Sorry!
Thanks
Martin Bailey
-------------------------------------------------------------
Senior Technical Consultant
+44 1223 873800
Global Graphics Software
http://www.globalgraphics.com
Developers of Harlequin & Jaws RIPs and Jaws
PDF Technology
___________________________________________________________________________
Date: Thu, 03 Mar 2005 07:01:14 -0700
From: Andrew Rodney
Subject: Re: A few statements to validate
On 3/2/05 10:29 PM, "Darren Bernaerdt"
wrote:
OK, so we have a couple of monitors that approach the
AdobeRGB
gamut.
As do I.
99.99% of users are not using such a device.
Today, no but that1s going to change in a big way. And
just because you have a display with a tiny gamut isn1t a reason to funnel
your color into such a small space.
While I'll buy the
argument that there is clipping on the histogram in a
smaller space, how do
we edit (visualize on screen) a color that can not be
displayed?
I load an output profile for my device as a start.
There are still colors that fall outside that gamut.
I've yet to
encounter a printer profile that even begins to
approach the gamut of
ProPhoto RGB.
None exist. Just like there are no printers that have
the sRGB or Adobe RGB (1998) gamut. But the container of the larger space
allows me to contain the colors that do fall into device gamut but outside
of sRGB gamut. And there are a lot of such devices.
I would dearly like to vastly expand the range of color
that I
can reproduce - can you recommend some printers that
approach the gamut of
ProPhoto RGB?
No such printer exists and we don1t want to work with
working space that are based on specific output devices. That1s why we have
these synthetic spaces in the first place.
Since this is offered in the monitor profiling packages
that I've looked at,
don't you think that it's likely these users are still
choosing 1.8 because
of historical advice?
The packages have to allow for legacy use like the OS
vendor (in this case Apple). But some packages let you aim for all kinds of
odd TRC gamma settings, that1s not a reason to use such a setting.
Sure, 2.2 or native is better, but what do you do in
the real world when your client has set 1.8 and
complains your images are
dark?
All my clients use 2.2 as do I. In an ICC aware
application, the previews are prefect (and in fact better than if one had
used 1.8; less/no banding). Outside ICC aware applications, everything
appears a tad dark which is quite easy to get used to and not at all an
issue.
I'd like to inform my students what is best, but also
help them understand
the realities that they may be confronted with.
A true native TRC gamma is best. 2.2 is next best.
Andrew Rodney
http://digitaldog.net/
___________________________________________________________________________
Date: Thu, 03 Mar 2005 10:35:57 -0500
From: Dolores Kaufman
Subject: Re: A few statements to validate
Ok guys, I'm one of those legacy Mac users who has had
1.8 drilled into my head. I admit it. But one of the things that was
drilled into my head was that 2.2 shows images DARKER than 1.8 and, indeed,
that has been my experience as I have calibrated my monitor both ways. An
image always appears darker when I have calibrated to 2.2, so I am having a
hard time understanding the above statement. If an image appears darker in
2.2 coesn't that cause you to lighten it and wouldn't that image then look
lighter handed off to a monitor set to 1.8? Further, when my monitor is
calibrated to 1.8 and the color space of an RGB file is Colormatch RGB,
when previewed in Photoshop as it would appear on a Windows machine the
image gets considerably darker. How then would an image prepared on a
Windows machine at 2.2 appear darker on a Mac at 1.8? Is there something
I'm missing here? Is the client looking at the images on his monitor (1.8)
or your monitor (2.2) when he complains that they are too dark?
Thanks,
Dolores
___________________________________________________________________________
Date: Thu, 3 Mar 2005 09:32:28 -0800
From: Paul D. DeRocco
Subject: RE: A few statements to validate
In Photoshop, or any other color-managed application,
the images won't look darker or lighter depending upon the gamma, because
it will convert the image using the embedded profile.
The advantage of 2.2 is that it puts midscale numeric
values closer to what people would consider medium gray.
Ciao,
Paul D. DeRocco
___________________________________________________________________________
Date: Thu, 03 Mar 2005 09:58:01 -0700
From: Andrew Rodney
Subject: Re: A few statements to validate
On 3/3/05 8:35 AM, "Dolores Kaufman"
wrote:
But one of the things that was drilled into my head was
that 2.2 shows images DARKER than 1.8 and, indeed, that
has been my
experience as I have calibrated my monitor both ways.
Outside a smart ICC aware application like Photoshop,
yes. But inside something like Photoshop, no. The ICC profile that
describes how you calibrated the display will be used in displaying your
images. This is how the same image on a PC (using 2.2) and a Mac (1.8) can
appear the same. But the 2.2 TRC is going to produce better behavior (less
banding in darks) since this is much closer to the native gamma of the
display.
Further, when my monitor is calibrated
to 1.8 and the color space of an RGB file is Colormatch
RGB, when previewed
in Photoshop as it would appear on a Windows machine
the image gets
considerably darker.
The TRC gamma of a working space has NOTHING to do with
the TRC gamma of your display. They only share the word Gamma. They do not
need to match. The gamma of the working space is the affecting how edits
are applied to the image.
Andrew Rodney
http://digitaldog.net/
___________________________________________________________________________
Date: Fri, 4 Mar 2005 11:34:04 -0700
From: Chris Murphy
Subject: Re: A few statements to validate
In the old days yes. That was before "display
compensation." Today there is a distinction between the tone
reproduction curve used in an image, versus the display. The difference
between the tone response of 1.8 in an image, and 2.2 on a display is
handled through display compensation. The key part of making this work
correctly is that applications need to know both the tone response of the
image and the tone response of the display. This is defined with a profile
for the image: the color space assigned and hopefully embedded into your
images; and one for your display.
Only non-color managed items, like your desktop
pattern, menus, some palettes and borders, would be affected by calibrating
your display to 2.2 rather than 1.8.
Chris Murphy
Color Remedies (TM)
www.colorremedies.com/realworldcolor
___________________________________________________________________________
Date: Sat, 05 Mar 2005 03:13:43 -0000
From: "ray_maxwell2000"
Subject: Re: statements to validate
Sorry Richard, I have to disagree.
Did a photographer who used to shoot transparencys need
to know how to separate to CMYK?
A Photographer should be able to hand off a file with
an ICC profile in a standard color space and the prepress house or printer
should know how to separate it. The file should be made to DISC
standards. If they don't want to do this they should give a profile of
there proofing color space so that the photographer can do the separation
for them.
How can a photographer do a good separation without
knowing all of the details of the press, paper, inks and screening used to
make the plates? He cannot.
What schools should teach is DISC standards.
Photographers should know how to deliver a calibrated RGB file to
DISC standards and prepress houses and printer should know how to separate
these files to their printing color space.
See this URL:
http://www.disc-info.org/
Standards allow us to communicate accurately. Of
course if you like to turn each job into a big trial and error process with
many times around the loop you can ignore standards and waste a lot of
time.
We can practice printing as art and craft or we can
treat it as a manufacturing process that uses statistical process control.
Both ways work. One costs less than the other.
Thanks for your attention,
Ray Maxwell
___________________________________________________________________________
Date: Sat, 5 Mar 2005 08:24:48 EST
From: Dan Margulis
Subject: Re: A few statements to validate
Martin Bailey writes,
But the resolution you need is also image-dependent. A
sharp image with
fine detail, especially fine diagonal rules (including
resolvable hair
strands) requires a much higher resolution than a
soft-focus image
Martin's entire message is the best brief summary of
the issues impacting desired resolution that we've seen in a long time. I'd
like to add one more variable.
Few people have taken the time to seriously test how
the relation between resolution and screen ruling really affects output.
Those who have generally have supported the conventional wisdom that
resolution should be between 1.5x and 2x the screen ruling. Those who have
gone deeper agree with Martin, that the needed resolution is
image-dependent, and also that the higher the screen ruling the smaller the
ratio needed.
All of this conventional wisdom, however, dates from
film-to-scanner images. Digital captures are smoother. They don't require
quite as much resolution. I am not aware of anybody who's run serious
tests, but my feeling is that 1.3x screen ruling for a digital capture
isn't all that unreasonable in principle.
I'm not sure it's wise to suggest to students that 1.3x
should be a rule of thumb, though. You always want a little resolution in
reserve, just in case the picture gets resized down the line.
Dan Margulis
___________________________________________________________________________
Date: Sat, 05 Mar 2005 09:09:08 -0600
From: Jim Bean
Subject: quick comments ref: statements to validate
ray wrote:
Did a photographer who used to shoot transparencys need
to know how to
separate to CMYK?
It would have been nice, but certainly not required or
expected.. Times have changed.
Fewer people in the loop/process.. Many times if a
problem arose.. guess who caught the heat.. the person at the bottom of the
heap, the photographer..many times simply by default.. Today many
photographers have the opportunity to step up to the plate and deliver
those services.. several advantages: such as accepting the responsibility
and being paid accordingly.. also when you are creating the original images
you have the background/experience to exposes/create/manipulate on the
front end knowing that downstream you will rectify the issue and improve
the final output.. I don't agree or disagree with your comments.. I
would simply state that the more education/experience/skill set the better
for all concerned..
Two candidates are applying for a project..
identical skill sets except one has cmyk bgrnd the other says, " we
didn't do that.. we deferred to the prepress-printing team they know what
is best for their printing conditions" which person would you select
for your project? enjoy the weekend, jim bean
___________________________________________________________________________
Date: Sat, 05 Mar 2005 08:58:29 -0700
From: Andrew Rodney
Subject: Re: Re: statements to validate
On 3/4/05 8:13 PM, "ray_maxwell2000"
wrote:
Did a photographer who used to shoot transparencys need
to know how to
separate to CMYK?
In the old days (19801s) when I was in photo school and
later shooting, I sure didn1t. We had one class on the subject and most of
us ditched to print in the darkroom (boy in hindsight was that dumb).
A Photographer should be able to hand off a file with
an ICC profile
in a standard color space and the prepress house or
printer should
know how to separate it.
In an ideal world, yes I totally agree. But I1ve been
handing off tagged RGB files to printers and service bureaus and have seen
some pretty butt ugly conversions from the files. You do realize that many
in the field, when given an RGB file (tagged or not) end up with their
heads exploding all over the place.
How can a photographer do a good separation without
knowing all of the
details of the press, paper, inks and screening used to
make the
plates? He cannot.
He can separate to the contract proof which is a lot
more doable.
What schools should teach is DISC standards.
Photographers should
know how to deliver a calibrated RGB file to DISC
standards and
prepress houses and printer should know how to separate
these files to
their printing color space.
And printers by and large need to understand that
standards are to be met, not 3exceeded2. If everyone who said they
printed to SWOP actually printed to TR001 (or DTR004 for sheetfed), we1d
all be in a much better place.
Andrew Rodney
http://digitaldog.net/
___________________________________________________________________________
Date: Sat, 05 Mar 2005 13:05:12 -0500
From: Lee Clawson
Subject: Re: Re: statements to validate
Ray,
Did a photographer who used to shoot transparencys need
to know how to
separate to CMYK?
No. But they did better knowing what happens to images
when printed. Students seeing prints from a darkroom, conversion of trans
to neg to print, was an eye opening experience to those who had only seen
their work on the light table. And those that did understand how we thought
and looked at the density range and color gamut of film on a scanner were
able to provide better work from the onset.
How can a photographer do a good separation without
knowing all of the
details of the press, paper, inks and screening ......
I agree, it's a problem. Many times we start design and
photography before the printer (and press/paper) has been decided on and
just as often it changes later.
Asking photographer students to simply follow DISC
doesn't strike me as a solution. I hope they've have a good foundation in
tone, contrast, color, sharpness and holding detail in desired areas. Often
I get files in which someone has or has tried to follow all the rules with
the software but misses basics; highlight details are blown out, white
balance is off and sharpness is too low.
With regard to resolution I also agree with Martin
Bailey. We've been able to use lower resolution digital captures in many
end products. I'd like Dan to run a story like one he did years ago about
resolution and sharpness using digital capture.
Lee
___________________________________________________________________________
Date: Sat, 5 Mar 2005 13:27:19 EST
From: Dan Margulis
Subject: Re: Re: statements to validate
Ray Maxwell writes,
Sorry Richard,
This list has been in existence since early 1999. AFAIK
in that time there has never been an occasion when I so thoroughly
disagreed with every thought expressed in a post as I do with this one.
Did a photographer who used to shoot transparencys need
to know how toseparate to CMYK?
Absolutely--but unfortunately, it wasn't feasible.
Without the ability to control the separation, he was at the mercy of the
supplier. But to be able to compete would have required an outlay of around
a million dollars.
That system was a great leveller. Mediocre
photographers had a safety net in the scanner operator who was unlikely to
overlook gross quality issues. Great photographers were stifled by the same
system, unable to get what they wanted to because important aesthetic
decisions were made by scanner operators who weren't really up to the
challenge. Plus, many careers of promising photographers were made
more difficult (if not ruined) by service providers who blamed all bad
prepress and bad printing on poor photography.
Today, understanding the separation process is no more
or less desirable than it was then--but it doesn't cost a million dollars
now. And now, the mediocre photographer is completely exposed--nobody is
going to save him if he submits a lousy RGB file, they way they would if he
submitted film. The photographer who can go straight to high-quality CMYK
has an enormous quality advantage that never existed in the days of film.
More than ever, merit is rewarded and incompetence is punished.
A Photographer should be able to hand off a file with
an ICC profile
in a standard color space and the prepress house or
printer should
know how to separate it.
When this happy state of knowledge develops among
printers, do let us know. Meanwhile, those photographers who are interested
in getting quality results will have to take matters into their own hands.
The idea of guaranteeing quality by embedding Eficolor or some other type
of profile is totally last-century. We are in a different age now.
How can a photographer do a good separation without
knowing all of the
details of the press, paper, inks and screening used to
make the
plates? He cannot.
The large majority of separations--including those made
for the highest-end advertising--are now and always have been made without
such knowledge. It's nice to have it, but what if you don't? Those who get
bad results generally get them because they ignore basic principles, not
because they don't have a full description of the printing conditions.
What schools should teach is DISC standards.
Photographers should
know how to deliver a calibrated RGB file to DISC
standards and
prepress houses and printer should know how to separate
these files to
their printing color space.
In view of the fact that DISC advocates Adobe RGB, and
the fact that an increasing number of service providers treat *all*
incoming files as sRGB, the above recommendation amounts to advocating that
the students commit professional suicide.
Standards allow us to communicate accurately. Of
course if you like
to turn each job into a big trial and error process
with many times
around the loop you can ignore standards and waste a
lot of time.
Standards are unquestionably desirable. Many of today's
problems are caused by everyone advocating their own way of doing
something, declaring that it's a "standard" and then cursing out
everybody who doesn't "comply" with it.
Assuming that the world uses DISC "standards"
and just handing off an Adobe RGB file to a stranger definitely turns the
process into one of trial and error. And, handing it off responsibly does
waste a lot of time--in today's sRGB world, anybody who wants to give an
Adobe RGB file to someone they don't know needs to get WRITTEN, not verbal,
confirmation that that someone understands what to do with it.
We can practice printing as art and craft or we can
treat it as a
manufacturing process that uses statistical process
control. Both
ways work. One costs less than the other.
Neither way works without the other. Both are
prohibitively costly, in comparison to providing craftsmanship *with*
reliable process control.
The incredible statement that the choice is between
craftsmanship and process control is to say that we must choose between the
spaghetti and the sauce, the engine and the tires, the words and the music.
Dan Margulis
___________________________________________________________________________
Date: Sat, 5 Mar 2005 10:49:32 -0800
From: Richard Chang
Subject: statements to validate
In response to Ray Maxwell's comments:
Sorry Richard, I have to disagree.
Did a photographer who used to shoot transparencys need
to know how to
separate to CMYK?
Most did not and as such, were at the mercy of the
client's budget to obtain renderings on press, that were faithful to the
'chrome's emotional content.
A Photographer should be able to hand off a file with
an ICC profile
in a standard color space and the prepress house or
printer should
know how to separate it. The file should be made
to DISC standards.
If they don't want to do this they should give a
profile of there
proofing color space so that the photographer can do
the separation
for them.
You use the term "should" far too often.
The realities of the process haven't changed all that much since the
days of transparencies 'till now, with the execption of those shooters
(I'll use Lee Varis as an example) who do understand the craftsmanship of
the new millenium. In the old days of transparency, probably 5% of a
shooter's annual work went into a portfolio, not because only 5% of the
work was sound, the low percentage is more related to the poor press
rendering of an otherwise good looking chrome. Why a poor rendering?
There are plenty of reasons why, but the solution for most of them is
a larger budget, whose lack factored into the poorly rendering job
(assuming of course that the chrome was acceptable). Take the same skillset
that scaled tonality onto the chrome and use it to scale tonality onto the
press; Photoshop and a digital workflow allow this.
How can a photographer do a good separation without
knowing all of the
details of the press, paper, inks and screening used to
make the
plates? He cannot.
Of course he can. He does this by asking the same
questions that the separator asks. Please bear in mind that the
separator's don't always know the answers to these questions either but it
doesn't stop them from making appropriately educated decisions on a job.
I make my own CMYK as do many of my customers (I'm the
training and education guy for MegaVision, Inc.; we make digital camera
backs for professional shooters) We've taken Dan's class and we know
what to ask, what constitutes an approprate ink load and black plate for
what we're shooting; with respect to the paper quality we're rendering on.
If you haven't taken Dan's class I highly recommend that you do. I'm
guessing that you haven't taken the class or you wouldn't be making the
comments you're making!
This list is attempting to educate you naysayers who
believe that us shooters can't learn this stuff. I ponied up and
attended Dan's class in Toronto. If I can learn, then others can too.
This list is clogged with "shoulds" and "don't's and
exceptions to the rule, mostly with regard to setting this or that dialog
box with such and such a rendering intent, in this or that program, via
thus and such a RIP, for who knows what output device proofed with I don't
know what the display profile means. I wonder if the list members in
general would agree that color is getting easier, or more convoluted.
For now, craftsmanship is a necessary component for those who are
interested in imaging of the highest order (and it's not just output, it
includes camera craft, lighting, pre and post production; the entire
skillset of our most accomplished list members).
Let me suggest that if you took the pile of cash needed
to take Dan's Color Theory I class and compared it to the pile of cash
needed to purchase every color management application and measuring widget
you'd been advised to purchase in the last 5 years, you'd be surprised at
the discrepancy. Especially when you look at the printed results of
each path. Properly done, each result is good. How much do you want
to spend?, how much do you want to save? A Colortron
spectrophotometer was $1500 5 or 6 years ago, as was Dan's class. The
Colortron is close to worthless today and the education of Dan's class is
now more valuable with each new piece of hardware
because it allows me to see if the new stuff really
works.
What schools should teach is DISC standards.
Photographers should
know how to deliver a calibrated RGB file to DISC
standards and
prepress houses and printer should know how to separate
these files to
their printing color space.
The information on the DISC site presents nothing new.
It is of course common sense information but submitting DISC standard
files doesn't guarentee a good job downstream of handing off a file.
Viewing the site's Metadata fields makes me believe that this
information will be ignored by the separation folks. After one look
at what's contained therein, I'd ignore it too; it contains nothing of
value in output information.
Standards allow us to communicate accurately. Of
course if you like
to turn each job into a big trial and error process
with many times
around the loop you can ignore standards and waste a
lot of time.
Of course if you know what you're doing and you can
make a SWOP standard proof that meets your rendering goals, you can avoid
wasting a lot of time, and skip the errors of the folks downstream who
routinely ignore your standards. This list has been rife with
examples of shooters gripped in the "gotcha" of ignoring embedded
profiles. I will predict the same fate for the metadata embedded
intent your "standard"; it will be ignored often enough to be
problematic.
We can practice printing as art and craft or we can
treat it as a
manufacturing process that uses statistical process
control. Both
ways work. One costs less than the other.
We can actually do both, print artistically while
monitoring our processes. Now that we have digital control of our
workflow, we have an ability to measure each step of the process.
Scientific process suggests that we test, observe, adjust, test and
observe again; to satisfactory conclusion. Using this process to
affect an artistic rendering on the output of choice, is the goal.
Every worker can learn this if he or she desires. A photo
school is one of the places where our young people should get this
experience. If you're in the LA area, you can come an audit my
Digital Zone System class (no charge!) Tuesday and Thursday nights at East
LA Community College.
Richard Chang
www.TransitionOfTone.com
___________________________________________________________________________
Date: Sat, 05 Mar 2005 21:33:02 -0000
From: "ray_maxwell2000"
Subject: Re: statements to validate
Dan Margulis writes:
This list has been in existence since early 1999. AFAIK
in that time
there has never been an occasion when I so thoroughly
disagreed with every
thought expressed in a post as I do with this one.
Well Dan you did not disappoint me. Your response
lived up to my expectations.
First, let me say I don't disagree with everything you
said. I have no problem with any photographer doing their own
separations and taking your class or reading your books. I have read
your book cover to cover. I just wish that you could get more
prepress people and printers to take your course so they know what to do
with a well made DISC file when it is sent to them. I am disappointed
in how slowly the printing industry has been to embrace new technology and
learn to do their part in producing quality printing.
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