> > Hmm. I checked using my Rev D., and got a discrepancy of about 1% > at a luminance level of about 42 cd/m^2, which (last time I looked > into this) seemed close enough, given that I wasn't sure that the > reference (my display) was more stable than that. Looking at it again > however, I have found that this discrepancy is explained by a bug > in my driver - I've accidentally swapped the high and low gain > linearity factors :-( :-( :-( > Fixing this up and testing again over an average of 5 > readings of white with both drivers gives an error of 0.05%, > an improvement of 20! For my Rev A instrument the agreement > between the two drivers has a discrepancy of 0.02%. > > So it will be interesting to see if your error goes away > with this fix. > > [I note though that there is a 12% discrepancy between > the absolute values of the Rev A and Rev D instruments I have > access to - absolute calibration is notoriously difficult.] > > > > I also have a Rev.D Eye-One Pro (UV-Cut if that makes any difference). When do you expect a new build (RC3?) will be posted with this fix in it? How close are you getting to the release of 1.1.0 final? > Since the values read jump around slightly on my CRT, especially for >> dark readings (probably because of the Eye-One Pro which I've heard is >> weak at low luminance), >> > > The combination of a CRT display and the i1pro is not as refined as some > of the dedicated colorimeter such as the DTP92 or DTP94 which have > hardware synchronization to the CRT refresh period. All you can > do with the i1pro is to use a long enough integration time to make > the refresh influence small. A longer integration time also improves > low light accuracy. A more interesting option might be > to have a mode for dispcal and dispread to use the i1pro adaptive > reading mode rather than a fixed integration time. This should > result in longer integration times for darker values. > > Graeme Gill. > > Is there a setting for integration time in Argyll? If you create a test build with that adaptive reading mode enabled, feel free to email it to me an I'll test it out.