Re: Scanning in CMYK vs. RGB
Re: Scanning in CMYK vs. RGB
- Subject: Re: Scanning in CMYK vs. RGB
- From: Don Hutcheson <email@hidden>
- Date: Tue, 13 Nov 2001 13:15:50 -0500
I can't resist. To quote Eddie Murphy (Shreck DVD, special features) "pick
me! pick me!"
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I need an argument settled. A friend of mine is using a drum scanner and is
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letting the scanner convert the file to CMYK. My recommendation was to scan in
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RGB and let Photoshop CMYK setup handle the conversion process to CMYK. My
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argument was for *better* control over the conversion process-- adjusting ink
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limits and control for dot gain depending on your final destination device. I
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told my friend they only thing that needed to be adjusted on the pre-scan was
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white/black point setting, but save it as RGB. He replied that most of his
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settings were done directly via the drum scanner including the CMYK
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conversion.
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Ok. Anyone want to tell me the advantages of doing this conversion process at
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the scanner? I told him once you're locked into CMYK, there's really no way to
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go back. RGB provides more flexibility in the long run, since you still have
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control of your conversion process at a later point in time.
Your argument is nearly right, but I would caution you not to pit
Photoshop's default CMYK conversion against a good drum scanner. To win that
battle without egg on face you need a very good CMYK ICC press or proofer
profile and a good RGB scanner profile.
Here are a few excerpts from an article called "RGB_Arguments" which many
people have found useful in winning this very argument. You can download the
full article and enough free supporting material to teach yourself more than
you ever wanted to know about color management at;
http://www.hutchcolor.com/CMS_notes.html
Excerpts:
"Scanning, retouching, assembling and archiving images in RGB offers major
quality and productivity advantages over traditional CMYK workflows. But it
took ICC color management to make RGB feasible in a CMYK world. This paper
explains the reasons behind our CMYK traditions and offers some compelling
arguments and useful tips for switching to RGB."
.....
"Because color management treats every device in the chain independently
( device-independent color9), it allows a powerful new change in how images
are scanned, edited, archived, separated and retouched. Instead of making
CMYK separations directly on the scanner, each scan can now be made without
output-specific adjustments and saved as a raw9 RGB file. The raw RGB file
can then be converted to CMYK or whatever output format is needed as a
separate, post-scan function through software like Photoshop(R) or
LinoColor(TM). Not only can CMYK conversion be delayed till long after the
original scan is made, but all color corrections or edits9 needed to
optimize or correct the image can also be made on the raw RGB file, prior to
its conversion to CMYK.
Two things make RGB editing feasible in a CMYK workflow:
1 ICC destination and display profiles let retouching software like
Photoshop display an accurate preview of the CMYK press sheet while the RGB
file is being worked on.
2 The operator can measure true CMYK percentages even though the file is
still in RGB.
Thanks to these conveniences, traditional CMYK users can easily take
advantage of the many benefits of RGB retouching."
.....
"There is a natural reluctance among experienced workers in any field to
make the switch to new technologies. Many CMYK workers just don9t feel like
putting in the effort, or feel daunted by the challenge of learning to work
in RGB. Some are concerned that it will undermine the value of their current
skills. Others fear that it will put the clock back and bring their value
down to that of a newcomer with no experience. While understandable, none of
these concerns is valid in a properly set up ICC workflow, because;
1 The changeover from CMYK to RGB is much quicker and easier than most
people realize.
2 This is just a new way of doing the same old job. The real skill lies in
analyzing a problem and knowing when it is fixed. The particular tool or
workflow is almost incidental.
3 When a skilled CMYK scanner operator or retoucher adapts to the RGB
approach, they become more valuable than before because they maintain the
ability to interpret CMYK values, which newcomers cannot.
4 Working in RGB is simply part of the natural evolution of the graphic
arts. If it wasn9t this it would be something else. Be prepared for more
changes in the future.
5 Anything that can be done in CMYK has an equal or better approach in RGB,
but not everything you can do in RGB can be done in CMYK.
.....
I hope this helps.
Don
*************************************
Don Hutcheson
Hutcheson Consulting
(Color Management Solutions)
Phone: (908) 689 7403
Mobile: (908) 500 0341
email@hidden
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