[argyllcms] Re: Multiple issues with Argyll, please help

  • From: Florian Höch <lists+argyllcms@xxxxxxxxx>
  • To: argyllcms@xxxxxxxxxxxxx
  • Date: Tue, 19 Aug 2008 18:25:58 +0200

Hello,
1. On my G70, with Argyll's calibration the image's black level is raised......all blacks are now grey-ish. I get much better shadow detail now but no true black. This defeats the purpose of having a CRT projector. Is there a way to tell Argyll not to raise the black level? 2. The results for low IREs are not good, they are very greenish. This may be a meter limitation but does Argyll take multiple readings at low IREs and average them out? 
Is there a way to manually change the .cal file?
maybe try the -f1 and -k0 options of dispcal. -f1 should help with the "gray blacks". Alernatively try using the -a option or measure ambient light when calibrating (if you have for example a i1 Display 2, which allows this). -k0 will not try to correct black point hue, which might eliminate the green cast. 


3. Only while calibrating my CRT projector and only while using the -F option (which 
makes the background black) dispcal gets stuck at a red patch, I think it is patch #25 or 
something. The error is "no data from sensor" or something similar. Hence I am 
never able to run dispcal to completion when using the -F option. That -F option is very 
important for my CRT PJ.

Strangely, the -F works fine on all other displays like LCD or plasma.
Most instruments have problems measuring very dark patches on devices that produce very low black levels (I have an old CRT here that measures a contrast ratio of about 1100:1 if the measurement window is surrounded with a gray background and when I try to measure an absolute black screen, the reading usually fails - I have an i1 Display Clorimeter). But you said it is a red patch? This seems strange.
4. On my plasma TV the green primary is way off. It is much more saturated than reference. I was hoping that Argyll, being a CMS, will correct it......it does not. What's up? I am doing something wrong?
Are you using just dispcal? With it alone you cannot correct this (just neutrals, tone curve, white and blackpoint). You need to use colprof in addition to create a profile, and use that with a color mangement aware application that can actually use the profile. Also, what do you refer to when you mention "reference"? 


5. If running dispcal and option 2, I check the whitepoint color 
temp.......Argyll reports that my patch is way off. It tells me to increase the 
red. With HCFR (another calibration metering software) I can see that the 
whitepoint is spot on! Even my eyes can tell that it is nearly perfect. Why 
does Argyll think that the readings are not close to 6500?


What is the reported color temp and dE to the locus?

Regards,

Florian Höch

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