Hello Brandon!
If you take a look on ti3 gamut, you will find strange spike at the deep
shadows.
I made screenshots of (1430-2Step)
(B_1430_PC+IJMKp_Fnst-PLustr_PPSG_PRH_1792A2.ti3)
This screenshot shows VRML gamut.
Unfortunately, ArgyllCMS has no utility to create VRML directly from ti3
file, so it's necessary to make a trick.
In 1st step I made Lab.tif from ti3 in Logo ColorLab (one patch->one
pixel), then I made VRML of this Lab.tif with the string (tiffgamut.exe
-v -d 1 -w -k Lab.tif).
I checked this ti3 gamut with another tool, it also shows the same spike.
THis spike consists of equal RGB values - 0/0/0, 2/2/2, 4/4/4, 6/6/6.
And it's neutral despite the common gray balance of this profile is
terribly greenish.
So I think, the "intellectual color adjustment" of printer driver was
not switched off. And it made his dirty work in shadows.
I would doublecheck the driver settings.
PS: Also I think, that -g128 -s32 is too much! It's no necessary to have
so many steps in gray, your printer and measurement device are not so
accurate. And possibly 32 single channel steps also too much. I think
that steps every 5% (-s21) is quite enough.
PPS: By the way, Graeme, what do you think about adding such feature to
iccgamut? I mean possibility to create a gamut file or VRML file of the
color gamut of a ti3 file.
Best regards,
Alexey Gribunin.
On 07/05/2020 06:05, Brandon Bates wrote:
I'm having trouble with the shadow transition to black on some printer profiles. My R300 (dye ink) profiled wonderfully with smooth transitions matching my monitor very well. My 1430 that I transitioned over to pigment ink is having some trouble in the shadows/darker hair (tried several times/ways now). Link attached with profile data and test results image (orginal + scanned results). When I tried profiling my laser printer, I had some similar issues (Also tried several different times). Adding -r4 *kinda* helps the problem in that it starts to smooth out the transition, at the cost of the ultimate black level being raised (not good either...).
Here are my command lines, which have worked well in the past:
targen -v -d2 -G -f891 -g128 -s32 "1430_891A"
printtarg -v -ii1 -M 0 -p215.9x370 -a 0.95 -A 0.8 -R 1 -P -L -t 300 "1430_891A"
chartread "1430_891A"
colprof -v -qm -r0.5 -i D50 -Tr -o 1931_2 -S "sRGB.icm" "1430_891A"
Is there a tunable to tweak? Am I missing something?
Comparision images:
http://www.brandonbates.com/images/natalietestprintscanned.jpg
"Good" R300 dye profile
http://www.brandonbates.com/images/EpsonR300_2Step.zip
"Poor" 1430 pigment profile (2 step)
http://www.brandonbates.com/images/1430-2Step.zip
"Poor" 1430 pigment profile (retry with cal first ,then 1 step)
http://www.brandonbates.com/images/1430-Cal-1Step.zip
Attachment:
Spike.jpg
Description: JPEG image
