[argyllcms] Re: Bad measurements & white point calibration with Argyll 0.7b7 and GretagMacbeth i1Display 2

  • From: Graeme Gill <graeme@xxxxxxxxxxxxx>
  • To: argyllcms@xxxxxxxxxxxxx
  • Date: Fri, 11 Jan 2008 00:33:35 +1100

Craig Ringer wrote:

$ dispcal -r -y l
Place instrument on test window.
Hit Esc, ^C or Q to give up, any other key to continue:
Current calibration response:
Black level = 0.19 cd/m^2
White level = 2.30 cd/m^2
Aprox. gamma = 2.23
Contrast ratio = 12:1
White chromaticity coordinates 0.3176, 0.3404
White    Correlated Color Temperature = 6187K, DE to locus =  8.5
White Correlated Daylight Temperature = 6186K, DE to locus =  4.8
White        Visual Color Temperature = 5911K, DE to locus =  8.3
White     Visual Daylight Temperature = 6043K, DE to locus =  4.6
The instrument can be removed from the screen.

Obviously something drastic is wrong.

From your file 2407_D65_G2.2_Bunset.calib_log, the command line was:

bin/dispcal -v -y l -t 6500 -b 2.2 calib

Setting up the instrument
Place instrument on test window.
Hit Esc, ^C or Q to give up, any other key to continue:
Display type is LCD
Target white = 6500.000000 degrees kelvin Daylight spectrum
Target brightness = 2.200000 cd/m^2
                    ^^^^^^^^
Target gamma = 2.200000

so you have set a target white of 2.2 cd/m^2. Perhaps
this is a typo, and you meant:

bin/dispcal -v -y l -t 6500 -g 2.2 calib ??

Graeme Gill.

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