[argyllcms] Re: Am I stupid or is it something else... my color management sucks.

  • From: Roger Breton <graxx@xxxxxxxxxxxx>
  • To: argyllcms@xxxxxxxxxxxxx
  • Date: Sun, 11 Apr 2010 08:17:34 -0400

Magnus,

I have two Spyder2 here and one of them results in profiles with a terrible
green cast. I would not be surprised that the instrument itself is the
source of your problems. 

Roger

> -----Original Message-----
> From: argyllcms-bounce@xxxxxxxxxxxxx [mailto:argyllcms-
> bounce@xxxxxxxxxxxxx] On Behalf Of Magnus Berg
> Sent: 11 avril 2010 07:40
> To: argyllcms@xxxxxxxxxxxxx
> Subject: [argyllcms] Am I stupid or is it something else... my color
> management sucks.
> 
> Hi, I'm new to the list and got a big problem.
> 
> I bought me a used Spyder 2. Realized that my old CTR couldn't produce
> enough light (90 cd/m^2 not 140 cd/m^2 that sRGB require). Digged a deep
> hole in my wallet and bought a quite expensive NEC 2690WUXI2. Now my
> color managed application show a green cast after calibration and
proofing.
> It's not fun at all. :-(
> 
> 
> This is how I do the calibration and proofing:
> 
> I use dispcalCUI. After that I had use the screen's OSD to set the 'White
> point', 'White level' and 'Black point' i got this nice values then I do a
'Check
> all':
> 
> Doing check measurements
> Black = XYZ   2.28   7.37   0.00
> Grey  = XYZ  27.17  28.58  31.02
> White = XYZ 130.26 137.22 149.83
> 1%    = XYZ   1.38   1.46   1.58
> 
>    Target Brightness = 140.00, Current = 137.22, error = -2.0%
>    Target 50% Level  = 50.07, Current = 28.58, error = -15.4%
>    Target Near Black =  1.37, Current =  1.46, error =  0.1%
>    Target white = x 0.3128, y 0.3291, Current = x 0.3121, y 0.3288, error
=  0.38
> DE
>    Target black = x 0.3128, y 0.3291, Current = x 0.3120, y 0.3299, error
=  1.22
> DE
> 
> 
> Then dispcalGUI send this command to dispcal:
> dispcal -v -d1 -c1 -yl -P0.500317863954,0.485345838218,1.0 -qh -t6500
> -b140 -G2.2 -f0 -k0 -A4 -B0.0001 colprof -v -qh -al
> 
> Before, then I only did a -qm calibration, I got strong red casts on my
> calibrated screen, and the profiled applications gave strong green casts.
The
> strange thing then was that the red cast only occurred on color
254,254,254 to
> around 249,249,249 but tones darker than that looked neutral grey with my
> eyes. After that I chose -qh this color tones and others looks neutral,
with my
> eyes.
> 
> 
> After that I load the calibration profile done after the command above I
got
> this then I run dispcal -r -yl:
> 
> magnus@debian:~$ dispcal -r -yl
> XRandR 1.2 is faulty - falling back to older extensions Place instrument
on test
> window.
> Hit Esc or Q to give up, any other key to continue:
> Current calibration response:
> Black level = 0.60 cd/m^2
> White level = 135.50 cd/m^2
> Aprox. gamma = 1.92
> Contrast ratio = 226:1
> White chromaticity coordinates 0.3099, 0.3266
> White    Correlated Color Temperature = 6676K, DE 2K to locus =  4.9
> White Correlated Daylight Temperature = 6676K, DE 2K to locus =  0.3
> White        Visual Color Temperature = 6490K, DE 2K to locus =  4.7
> White     Visual Daylight Temperature = 6664K, DE 2K to locus =  0.3
> The instrument can be removed from the screen.
> 
> 
> I understand nothing. How can I have gamma 1.92 and the above
> temperature then I chose to calibrate to 2.2 and 6500? And why is there a
> green cast on the pictures viewed in Color managed applications?
> 
> Did I understand things right:
> I should load the profile as a system wide screen calibration profile with
> dispcalGUI, the same as you do with dispwin -L. And then I load then same
> profile to the color managed applications as a screen color profile?
> It's then I load then profile into then color managed applications that
then
> green cast ampere.
> 
> I have struggled with this for weeks, and googled a lot, and reading this
mail
> list without finding any useful help. Therefor I ask you for help. The
only thing
> I want is a good color managed environment for working with sRGB pictures.
> 
> 
> 



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