ProfilerPRO part two
ProfilerPRO part two
- Subject: ProfilerPRO part two
- From: email@hidden
- Date: Thu, 30 Aug 2001 20:45:16 EDT
Continued from part one...
In a message dated 8/30/01 12:47:21 PM, email@hidden writes:
What is worse, the so-called "full control over black
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generation" has nothing to do with the profile you will eventually
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build: it merely determines, in a rather arbitrary way, which
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particular, severely limited subset of CMYK values your target will contain.
There is one practical limitation here; if you have no idea what ink limits,
dot gain, black generation curve, UCR/GCR and UCA settings you wish to use on
a device like a press, then ProfilerPRO will not allow you to print a "raw"
CMYK target set once, and make these choices later, which is not much of an
issue for in-house devices with direct print controls, but for a press the
make ready for another target would be a real issue. Of course I should point
out that if you don't know what settings your press should be using, you
probably shouldn't be profiling that press! <G>
Beyond this simple limitation, the process could be argued to be *superior*
to running a raw set of targets, and emulating setting to them later, or the
more common practice of limiting the targets in advance with a set of
liniarization curves, and applying those curves within the profile in front
of the color look up tables. After all, if PRO's method hideously limits the
targets (I would say accurately targets available values, and leaves out
irrelavant ones) then applying curves in advance would have to be similarly
viewed as limiting the target print... admittedly limiting to appropriate
values, and limiting it so that the ink won't drip off onto the floor, and
the web won't break!
How could the ProfilerPro method be superior? Because it actually *uses* your
settings when printing the target, rather than building an engine into the
software to *emulate* those settings later, and hopefully estimate the
correct result.
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Why do this instead of printing a fixed CMYK Photoshop file as the
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target? I can only surmise that it was much easier to create the
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*sensation* that you have control over black generation by tweaking the
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Photoshop settings (wrong, because you are merely altering the target
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CMYK values), than to provide actual black generation control in the
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profile-building process.
I would suggest it is to take advantage of the precision available by using
precorrected targets, and avoiding emulated settings and channel curves when
building the final profile.
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I repeat, it may be great for RGB profiles, and I have nothing but the
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highest praise for ColorVision's Optical and PreCal monitor profiling
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software, but ProfilerPRO for CMYK printers is a no-no.
So if the entire concept is impossible, why does it build such excellent CMYK
profiles? Admittedly there are a few non-standard RIPs out there that it has
trouble with, since they won't play ball in a way it can deal with, but thats
true of most profiling software. Don't let this convince you its incapable of
CMYK profiling, or that its CMYK profiling is definitionally inferior; I
would put it up against most any package (including some at five times the
price) for a lot of CMYK devices.
C. David Tobie
Design Cooperative
email@hidden