On Sat, 2008-12-06 at 17:15 +1100, Graeme Gill wrote: > Leonard Evens wrote: > > One thing that confuses me is that by appropriate choice of the default > > gamma setting---the monitor offers 3 possible settings, dispcal -r shows > > gamma = 2.2., but after calibrating/profiling and loading the > > calibration into the video LUT via xcalib, I get quite high gammas, in > > the range 2.6 to 3.1. I've even tried using the argument -g 2.2, but > > that doesn't seem to make any difference.. > > Gamma is hard to measure, because no-one can agree on > exactly what it is. If you use ambient light adjustment, > then the gamma may be boosted to increase the contrast. This seems to be the issue. If I don't use the ambient light adjustment, I get something close to the target gamma. I am using a Eye-One LT, and for ambient light measurement, I clip on the white plastic cover, which I believe is supposed to be used fro that purpose with the Eye-One software under Windows. But perhaps that is confusing matters. I also have an Eye-One Pro, which may do a better job with ambient light measurement. But I'm not sure at this point whether or not I should be using the ambient light measurement at all. When I calibrated/profiled this same monitor last year---I thought successfully---with version 0.8, there was no ambient light option. On another point, whatever I do, I always get a message like Failed to meet target 0.600000 delta E, got worst case 0.607690 with different worst cases. Does this mean anything? > > Normally the "dispcal -r" report should agree reasonably > with the target set using -g, if ambient compensation is > not being used. As I said, it does if I don't use the ambient light option. According to the `Amazing Gamma Applet', gamma seems to be between 2.1 and 2.4. I still feel I am having difficulties because I don't understand hwo to use Brightness and Contrast in the monitor controls. Also, with the RGB monitor controls set at the default 50/100, I am getting lower color temperatures than I would prefer. I will experiment some more with the controls and also try setting the color temperature. > > Graeme Gill.