Craig Ringer wrote:
I'm having some severe issues getting decent results out of an i1Display 2 using Argyll 0.7b7 . If I use dispcal to adjust the gains to target a D65 white point I end up with a bright purplish-blue display.
It's not clear where you see a problem. From your reference:
craig@wallace:~/build/argyll_0.7b7$ bin/dispcal -R -y l Place instrument on test window. Hit Esc, ^C or Q to give up, any other key to continue: Uncalibrated response: Black level = 0.19 cd/m^2 White level = 170.82 cd/m^2 Aprox. gamma = 1.72 Contrast ratio = 921:1 White chromaticity coordinates 0.3141, 0.3296 White Correlated Color Temperature = 6422K, DE to locus = 4.1 White Correlated Daylight Temperature = 6423K, DE to locus = 0.7 White Visual Color Temperature = 6282K, DE to locus = 3.9 White Visual Daylight Temperature = 6444K, DE to locus = 0.6 The instrument can be removed from the screen. The luminosity readings are fairly sane based on what i1Match has to say about the display,
> but the colour information is amazingly out. In what way is it "out" ? You've asked for a D65 white point, and that's exactly what has been achieved (according to the instrument at least). You've got Daylight 6500K within 0.6 delta E. Pretty good. Without calibration, the mid greys may not be aligned with D65 though, depending on how the display actually creates the R/G/B "gain" controls. [It doesn't follow that the display "gain" controls work in such a fashion that the chromaticities of all the greys will track the white point. It really depends on how smart the people creating the "gain" control function for the LCD display are, and the characteristics of the display.] If other white references in your visual field are a warmer white (D50 or lower for incandescent illuminants), then D65 will look very "blue". In contrast the "native"/sRGB display is not close to any normal white point (delta E 9). A poor result for the display (or a faulty instrument). [And the usual caveats about trying to change the basic nature of an LCD apply. It probably won't work very well compared to a CRT, unless you've got a LED R/G/B backlight LCD display. In such a display the mid greys will tend to track better, simply because of the nature of the physics involved.] Graeme Gill.
