RE: A thread about red
RE: A thread about red
- Subject: RE: A thread about red
- From: Joel <email@hidden>
- Date: Fri, 29 Jun 2001 16:43:06 -0500
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(clip)
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...still trying to absorb Henriks post,needed to read it a couple of times,but
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i have deleted it accidentally.
Accidentally? Or as a sanity measure?
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you are doing your conversions at the rip,so maybe thats were your losing
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me,i do all my conversions in PS
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and your post had me questioning my RGB workflow my default is set to
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RelCol,ACE BPC on.
My PS workflow was: RelCol, ACE BPC on in color settings
In softproof: RelCol no black ink no paper white
Convert to Profile: RelCol ACE BPC On
This seems to concur (i think) with what Henrik stated. But i
question the use of ACE now (when I never did before). Matching CMM
engine to destination profile CMM seems to remain a matter of
confusion for me, mostly due to my struggles with out of gamut reds.
But it makes more sense when looking at conversions absolutely.
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I must add:
I forgot to mention these particular workflows are for fine art
reproductions from original>scanner space>workspace Adobe>save as
TIFF then drag-n-drop with Color Correction ON. We are using custom
scanner, custom monitor, custom (and some canned) output profiles.
Not press.
On the RGBtiff image reproduction end I've been trying to convince
the powers that be that drag-n-drop RGB TIFF printing with Color
Correction ON, which then allows the RIP to handle RGB-to-Output
profile conversions, is not an ideal RGB workflow situation.
I prefer original>scanner space>workspace Adobe>media output profile
space>save as TIFF or print to Postscript then drag-n-drop with Color
Correction OFF. We are using custom scanner, custom monitor, custom
(and some canned) output profiles. No press output in this workflow.
My own work in Photoshop I do all conversions prior to printing to
the RIP (Scanvec-Amiable PhotoPrint and ColorChoice RIP software
Color Correction Off).
What gets me is RGB out-of-gamut color mapping, in particular RGB RED
(255) which prints bright via one Photoshop method (absolute) and
dull from relative and/or perceptual. Results vary widely from paper
profile to paper profile. Everytime I near a stage when I might win
the workflow argument, up pops a question I can't answer short, sweet
and demonstrably. If I cannot answer one, then the rest of my
demonstrations and arguments get thrown out till the next round -
which currently is RGB RED. Beyond the weak pigment ink position I
cannot explain why I can print Pantone 032 and a brighter RGB TIFF
RED on PVC vinyl using 6-inks, but can't get any bounce on canvas
with eight inks (CMYKLcLmOrGr)unless I work in Lab, which is not an
option at this point.
This then begs the question: "Why do I get a dull RGB RED response
from an Adobe1998 TIFF dragged-n-dropped onto the RIP than the same
TIFF saved as Lab then Drag-n-dropped on RIP? The brighter, richer
red from Lab TIFF shows the red can render richer. In short we blame
the profile.
In some cases: soft proof editing and output using Absolute
rendering, then same in convert-to-profile, and same in the RIP
output intent returns accurate on canvas using our custom profile,
inaccurate using canned canvas profile, inaccurate printing to art
paper using canned profile, accurate printing to PVC Vinyl using
canned profile. Try to analyze the data in these profiles? What's the
catch? Substrates? It's not white point/black point because the WP/BP
on the two accurate materials (canvas and PVC) is only -1 b (lab)
difference. (I have yet to write a profile for the art paper but this
gives me added incentive.)
This all brings us (me) back around to profile editing. I believe the
optimal RGB RED (and Green and Blue) is to be found in editing the
ink mix (RGB>CMYK table?).
What is the optimal mix of CMYK, or CMYKOG, or better yet, CMYKLcLmOG
to achieve the brightest response from RGB RED on a pigmented inkjet
printer? Green? Blue?
(I know I'm wandering....if anyone wants me to shut up...just knock
on my head a few times...)
--
joel johnstone - designtype
Winnipeg Manitoba Canada
(Absolutely relative in a perceptual kind of way.)