>Ah, well, I think what you've noticed is that between the... Graeme, I did some further testing. I copied the 3 bitmap screens that dispcal uses to calibrate the screen and put them in a directory where I could switch between them quickly using ACDSee. Then I ran 3 calibration checks (dispcal -r) using the bitmaps as displayed by ACDSee rather than the ones displayed by dispcal. To prevent dispcal from modifying the laptop display LUT I set my laptop screen up as a secondary monitor to my office LCD screen, and told dispcal to display on the office LCD - so dispcal modified the LUT for the office LCD and the laptop screen retained any LUT entries it had had while dispcal made the readings off the bitmaps as displayed by ACDSee on the laptop screen. :-) Below are 3 of these modified dispcal tests that I ran. The first is with no calibration or profile applied and matches what dispcal would report if run normally on the laptop screen. The second run is with the original dispcal-produced LUT loaded. The third is with the LUT loaded and the profile (created by "profile") applied (via ACDSee). The interesting finding is that the laptop screen with no LUT has a gamma of 2.24, with the LUT only applied the gamma is 2.03, and with both the LUT and the profile applied the gamma is 2.24 again! This seems to indicate that dispcal is creating a calibration curve with a low gamma and then "profile" is compensating and setting the gamma higher again. - Bill No calibration or profile applied: I:\Util\Argyll\profiles>..\bin\dispcal -v -d1 -yl -r -p .5,.5,1.25 Setting up the instrument Place instrument on test window. Hit Esc to give up, any other key to continue: patch 3 of 3 Black level = 0.30 cd/m^2 White level = 134.01 cd/m^2 Aprox. gamma = 2.24 Contrast ratio = 447:1 White chromaticity coordinates 0.3289, 0.3517 White Correlated Color Temperature = 5651K, DE to locus = 9.0 White Correlated Daylight Temperature = 5651K, DE to locus = 5.3 White Visual Color Temperature = 5410K, DE to locus = 8.7 White Visual Daylight Temperature = 5522K, DE to locus = 5.1 The instrument can be removed from the screen. Calibration only applied: I:\Util\Argyll\profiles>..\bin\dispcal -v -d1 -yl -r -p .5,.5,1.25 Setting up the instrument Place instrument on test window. Hit Esc to give up, any other key to continue: patch 3 of 3 Black level = 0.30 cd/m^2 White level = 134.22 cd/m^2 Aprox. gamma = 2.03 Contrast ratio = 447:1 White chromaticity coordinates 0.3291, 0.3518 White Correlated Color Temperature = 5643K, DE to locus = 8.9 White Correlated Daylight Temperature = 5644K, DE to locus = 5.3 White Visual Color Temperature = 5404K, DE to locus = 8.7 White Visual Daylight Temperature = 5517K, DE to locus = 5.1 The instrument can be removed from the screen. Calibration and profile applied: I:\Util\Argyll\profiles>..\bin\dispcal -v -d1 -yl -r -p .5,.5,1.25 Setting up the instrument Place instrument on test window. Hit Esc to give up, any other key to continue: patch 3 of 3 Black level = 0.58 cd/m^2 White level = 133.72 cd/m^2 Aprox. gamma = 2.24 Contrast ratio = 231:1 White chromaticity coordinates 0.3282, 0.3518 White Correlated Color Temperature = 5678K, DE to locus = 9.3 White Correlated Daylight Temperature = 5678K, DE to locus = 5.7 White Visual Color Temperature = 5425K, DE to locus = 9.0 White Visual Daylight Temperature = 5538K, DE to locus = 5.5 The instrument can be removed from the screen.