On Thu, Jan 8, 2009 at 9:58 AM, Graeme Gill <graeme@xxxxxxxxxxxxx> wrote: > > You get a White point error of zero if you've asked for the native > white of the display, rather than a specific color temperature or > chromaticity coordinate. The native white point (in your case) > is 17 CIEDE2000 units away from the black body locus (ie. > it is not very "white"). > >> When I afterwards profile my monitor I noticed that the profile have a >> whitepoint about the same as the calibrated monitor. Is this >> whitepoint still of the locus by DE 17? Anyway, images I have created >> whit this calibration and profile looks excellent on print, so I don't >> think this there is any problem in my daily use. > > Typically one adapts to the white of a monitor, although setting the > target temperature to the Visual Color or Daylight temperature > may be a better choice. > > Graeme Gill. > > > Graeme, sorry I send an email in wrong name. Thank you again. From now on I will always check my calibration. I have played a lot with this now. My monitor have a uncalibrated responds like this: dispcal -v -c1 -R -yl Setting up the instrument Instrument Type: DTP94 Serial Number: 053399 Boot version: D929 Software version: DB06 Place instrument on test window. Hit Esc, ^C or Q to give up, any other key to continue: patch 3 of 3 Measuring VideoLUT table entry precision. patch 6 of 6 patch 6 of 6 patch 6 of 6 Uncalibrated response: Black level = 0.26 cd/m^2 White level = 126.80 cd/m^2 Aprox. gamma = 2.38 Contrast ratio = 488:1 White chromaticity coordinates 0.3484, 0.3877 White Correlated Color Temperature = 4999K, DE to locus = 16.5 White Correlated Daylight Temperature = 5010K, DE to locus = 14.4 White Visual Color Temperature = 4570K, DE to locus = 16.1 White Visual Daylight Temperature = 4673K, DE to locus = 14.0 Effective LUT entry depth seems to be 8 bits The instrument can be removed from the screen. So instead of using native white point I have this concluded that at 5000K would be a naturally choice. I have the brightness at my monitor at 100, the rest of the settings are at factory default. I have tried with the daylight locus and the planckian locus: Heres the result: D50? dispcal -v -c1 -yl -m -t 5002.78 d50 ........ Brightness error = -0.166590 cd/m^2 White point error = 0.225363 deltaE Maximum neutral error (@ 0.321539) = 0.920143 deltaE Average neutral error = 0.457058 deltaE Number of measurements taken = 133 The instrument can be removed from the screen. Written calibration file 'd50.cal' $ dispwin d50.cal $ dispcal -yl -c1 -r Place instrument on test window. Hit Esc, ^C or Q to give up, any other key to continue: Current calibration response: Black level = 0.26 cd/m^2 White level = 98.88 cd/m^2 Aprox. gamma = 2.38 Contrast ratio = 380:1 White chromaticity coordinates 0.3451, 0.3592 White Correlated Color Temperature = 5025K, DE to locus = 5.5 White Correlated Daylight Temperature = 5026K, DE to locus = 1.0 White Visual Color Temperature = 4909K, DE to locus = 5.3 White Visual Daylight Temperature = 5009K, DE to locus = 0.9 The instrument can be removed from the screen. And here with planckian locus: dispcal -v -m -yl -c1 -T 5000 T5000 ...... Computing update to calibration curves... Doing iteration 3 with 64 sample points and repeat threshold of 0.600000 DE patch 64 of 64 Brightness error = -0.424535 cd/m^2 White point error = 0.244245 deltaE Maximum neutral error (@ 0.900364) = 0.668959 deltaE Average neutral error = 0.374921 deltaE Number of measurements taken = 122 The instrument can be removed from the screen. Written calibration file 'T5000.cal' dispwin T5000.cal dispcal -v -yl -c1 -r Setting up the instrument Instrument Type: DTP94 Serial Number: 053399 Boot version: D929 Software version: DB06 Place instrument on test window. Hit Esc, ^C or Q to give up, any other key to continue: patch 3 of 3 Current calibration response: Black level = 0.27 cd/m^2 White level = 92.01 cd/m^2 Aprox. gamma = 2.36 Contrast ratio = 341:1 White chromaticity coordinates 0.3447, 0.3513 White Correlated Color Temperature = 5013K, DE to locus = 0.0 White Correlated Daylight Temperature = 5011K, DE to locus = 4.8 White Visual Color Temperature = 5014K, DE to locus = 0.0 White Visual Daylight Temperature = 5114K, DE to locus = 4.6 The instrument can be removed from the screen. ----------------------- At lest the error is much better than with native white point. But I think there is some more banding and maybe some color cast compared to native white point. I also really wonder why the native white point is so far away from locus? I have also tried higher temperatures but I don't think my monitor have enough brightness to do that. Another nice feature of my monitor are, If I do a recheck after some time the white point may be off with 0.5 DE or even more to locus. :-( And here is an image of my kids taken in my living room straight before a Christmas party. They are edited in a DE 17 calibration :-) http://mulebakken.net/div/mykids.jpg Regards Lars Tore Gustavsen