[argyllcms] ICC files and OSX ; Missing target gamma in icc issue?
- From: "Christopher E. Brown" <chris.brown@xxxxxxxxxxxxx>
- To: argyllcms@xxxxxxxxxxxxx
- Date: Tue, 06 May 2008 05:05:42 -0800
I recently ran across a note that Argyll had added support for the
spider2. Since I had one of these around I spent a few hrs and had a
much better display setup on the *nix systems than I could get with
eyeball and a color card.
This is a very big win for me, other than the occasional VMware image
for work, I don't do windows, and color calibration has been somewhat
lacking since I retired my last IRIX station.
Getting more into my photography hobby lately, and have been looking for
better photo management and basic editing. After playing around with
iphoto and Aperture I picked up up a 24" iMAC and Aperture.
Thats where the fun started.
In goes about 7000 photos and out comes the spider2.
After about 2 days of confusing results I have an idea of the issue, but
am looking for a good smack to the head, and/or pointers. (Just a
network eng with a photo addiction, not a CMS expert)
I started by picking up beta8, and decided to do the all in one pass via
dispcal.
Went for 120cdm, gamma 2.2, 6500k.
Everything looked good, until I fired up Aperture, colors just off,
severe blowout in the highlights, etc...
Went back to the multi stage method, tried removing the cdm target, etc.
No luck.
Pulled the Apple 23" display of the Linux station and added as secondary
(thinking screwy iMAC display), same results.
The default Apple display profiles did not have the issue, they were
just way to bright.
After looking at iccdump output and colorsync reports on both my
profiles, the Apple ones and a number of 3rd part ones I noticed lack
that I think explains the issues.
All of the other profiles have a "Curve: Curve is gamma of <value>" in
each of the R G B tags.
The output of argyll does not.
It would seem to me that the color managed apps are assuming a default
display gamma around 1.8, and pre-adjusting for the source material
(sRGB). So I end up with photos being pumped to display as 2.2 on a 1.8
display when the display is already 2.2
I had assumed that I should calib for 2.2, so that even apps without
color management ability would display material the same as all of my
other systems (everything else I work with is 2.2).
Re-running everything with -g 1.8 produces profiles that closely match
expected.
Should I just stick with 1.8 and accept that non-managed apps will look
off with sRGB material?
Is there an option to profile or dispcal I am missing?
Is there some reason that the gamma target is not being included in the
icc profile tags? I was very confused for some time, but I cannot find
anything in the mailing list or google, or any suggestive command line
options beyond -g.
Thanks
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