ProfilerPRO part one
ProfilerPRO part one
- Subject: ProfilerPRO part one
- From: email@hidden
- Date: Thu, 30 Aug 2001 20:44:55 EDT
In a message dated 8/30/01 12:47:21 PM, email@hidden writes:
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Ernst and I have been having a private exchange on this subject for the
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past couple of days. In the end, based on what he tells me and is
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confirmed by the ColorVision documentation, I have to agree with Ernst's
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conclusion which probably prompted his remark: This software may be
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great for profiling RGB devices, but it is positively dangerous, and
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definitely useless, for profiling CMYK printers.
I have been profiling CMYK devices with excellent results with this program
for well over a year. At Seybold SanFransisco last September I introduced the
program to a large number of color consultants (many of them on this list)
and handed around images printed through ProfilerPRO CMYK profiles for a
PostScript RIP, and the only image quality comment I heard made was one
suggesting the excellence of the color (by Jon Meyer, I believe) while the
only criticism I recall hearing was that you couldn't actually draw your
black curve and toe as desired, a feature since added. Admittedly there are
some extreme (and for most uses unnecessary) settings not possible, such as
recurving the color channels back down hill to zero, to use less than 200%
total ink for blacks. If you wish to perform that type of trick, I wish you
well with whatever other program you do it with.
The alleged control
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over black generation, etc., is not only humbug, but actually covers up
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the monumental flaw in the design of this program when used for CMYK
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printer profiles.
Some might call it a bug, I would call it a feature <G>...
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Let me try to state this in simple terms:
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The program doesn't have a CMYK target. This would obviously be the most
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trivial of features to develop, so the reason isn't ignorance or cost
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saving, but probably quite different as we shall come to see.
Exactly...
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Instead, it uses a fixed (or three different sizes, in fact) RGB target
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only. To print a CMYK target, it tells you to load a particular
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Photoshop Color Setting, or to modify this, or to roll your own,
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whatever, which will transform ProfilerPRO's RGB target into a CMYK file.
Correct again... but only as a method if defining your target seperations,
the actual profile settings occur later, when you read this target back in.
Then the CMYK settings you have chosen are also used to build the profile.
The use of them up front could be compared to ink limiting or a liniarization
step to control the amount of ink from each channel printed to the target,
though they do more than that.
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All wrong. No way are you going to get from an RGB file through *any*
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Photoshop ink setup a full suite of CMYK values to probe the full gamut
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of the printer.
You might want to speak carefully here; a rather brilliant color scientist
came up with this scheme to do exactly that, and I can attest that the
results of it are excellent!
Continued in part two...
C. David Tobie
Design Cooperative
email@hidden