Re: FOGRA52 & i1Profiler [subject corrected]
Re: FOGRA52 & i1Profiler [subject corrected]
- Subject: Re: FOGRA52 & i1Profiler [subject corrected]
- From: "email@hidden" <email@hidden>
- Date: Mon, 11 Sep 2017 12:37:16 -0400
I’ve been reading this thread with some interest. What I offer is maybe not
perfect but I have spent a lot of time optimizing grayscale on the epson
printers (both making custom inks and doing this from the software end on Epson
inks).
There is a bunch of details missing in exactly what you want to do here, but
I’m assuming this is to build a epson contract proof workflow for a press, yes?
The problem is the halftone. If you are producing epson screened (epson
scp5000) images and trying to match to a press which uses larger dots
(half-tone screening) you will get a significant amount of color shift with the
smaller dots and (weirdly) less when using larger black dots on prices.
(That’s one thing). If you can simulate your press halftone this will help.
If you are using HTM dithers or epson screening, there is going to be some
funny stuff going on between cyan and black to “neutralize” the black ink in
the screening. Epson screening is used to maximize gamut and their ABW
screening is actually different (for neutrals) so they screening does make some
color instability in neutral. So you can use something like Stochastic 3 or
Smooth Diffusion (or whatever GMP offers) that is not epson screening and you
may get a better neutral optimization.
If you are dealing with old proof booth lights that spike in green (take your
spectro and do a reading off the lights to see using the illumination panel in
i1Profiler) you will see significant yellow shift even if the ink is just
slightly different.
There are a whole slew of problems when getting into the nitty gritty of
soft-proofing for “neutrals.” . . . that’s just a few.
If you have full linearization and channel control in GMP (I don’t know if you
do I haven’t looked) I suggest just deleting the C and M channels and treating
LC, LM, and Y as CMY and then linearizing (chroma) the LC, LM and Y channels.
Then LIMIT those channels to top chroma value and build a regular GCR and 100%
GCR profile for these in i1Profiler (3000 patches, D50etc, large table, normal
defaults, then evaluate). Keep smoothness up high around 70ish. Then do an
OPTIMIZATION of this profile using near-neutral LAB values. You can just create
that in excel as a cgats file . . . this will enable you to actually optimize
the neutral and rebuild the profile for given lighting conditions.
None of this will work as good as the SC10000 or SC20000 printers for neutral
axis optimization but it’s a start I guess. .. .
Best,
Walker
--
Walker Blackwell
Research & Development @ Vermont Photo Inkjet, LLC
piezography.com <http://piezography.com/>
cone-editions.com <http://cone-editions.com/>
inkjetmall.com <http://inkjetmall.com/>
community.inkjetmall.com <http://community.inkjetmall.com/>
--
Sent from my no excuse not to edit.
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