Re: PS CMYK Conversions
Re: PS CMYK Conversions
- Subject: Re: PS CMYK Conversions
- From: Mike Strickler <email@hidden>
- Date: Fri, 15 Aug 2008 08:50:42 -0700
Roger's comments below are wise. My sense from all of this is that
what some people want to do is just select Mode: CMYK and be done
with it. Thus the concern over the Photoshop default profiles (which
nonetheless could be updated). Unfortunately, that is how much CMYK
gets created today--in design studios and ad agencies. It often works
surprisingly well. Troubles begin when the RGB images are badly made
and have oversaturated color. Without some editing this will not
compress nicely into the press gamut. Even well made images will pose
significant problems when separated for printing on uncoated stocks,
especially tough for newsprint. People who do this work every day
simply know they must lighten their colors, avoid heavy shadows--
there's a skill to this and no one-click method will ever work well
enough to produce quality results. Rendering intent and gamut-mapping
methods also play a role here--perceptual is usually better for these
uncoated scenarios. Different CMYK profiles remap the colors
differently: Some methods (e.g. Logo Colorful) place a premium on
maintaining saturation, others favor smooth luminance gradations. So
choosing (or making) the right profiles for the conversions is an
important part of the job as well. It's not rocket science, but it's
still a craft, and discretion and skill are required to do it well
consistently. Device links are occasionally useful when repurposing
of images is needed, but this is a different subject. The issue at
hand is how to get a good CMYK sep in the first place. Maybe we
should also discuss when, where and by whom this work should be done,
and why so many printers are still asking for CMYK images from their
customers...
As far as sacrificing RGB color gamut to a so-called "small" press
gamut, I
would submit that only in extreme circumstances, as in very, very
saturated
colors, source RGB colors get clobbered in the conversion to the
"smaller"
press color space. Most images featuring human and natural colors
fit well
within the gamut of a GRACoL2006_C1 or ISO_12647-2:2005 calibrated
press.
Most images. So, passing images around encoded in those color
spaces does
not mean that all the precious original RGB colors have been
irrevocably
lost.
There are pros and cons.
Not everyone, for instance, is ready to embrace the idea of device
independence when it comes to CMYK printing. What about images
separated
with GCR techniques? Those just can't be repurposed on the fly without
incurring some loss in the original intent of the separation.
Bottom line, this whole thread was started because someone
questioned the
validity of converting images between RGB and CMYK in Photoshop. It's
interesting how it turned into image portability issues and press
gamut
bashing. People, there is no such thing as one universal solution or
workflow for color. There are just a myriads of well-justified
color needs!
It takes good judgement to decide on a given policy in each case
and we
should not succumb to ideals of universalism and absolutism.
And then we want to just
settle for a generic, usually smaller, color space? Seems counter
intuitive
to me. Safer, yes. But for the geek in all of us that likes to
push to the
limits, it's just not exciting.
Bob
Roger Breton
_______________________________________________
Do not post admin requests to the list. They will be ignored.
Colorsync-users mailing list (email@hidden)
Help/Unsubscribe/Update your Subscription:
This email sent to email@hidden