Von: Gerhard Fuernkranz <nospam456@xxxxxx>
Gesendet: 13.6.'09, 11:31
Karl Beckers wrote:
so what you're saying here is that if increased the color temperature
rather than decrease it, at some point the sRGB gamut would fit into
the monitor's gamut (provided the latter is large enough in the first
place)? I could try that. I just assumed picking the sRGB preset on
the display and keeping the native whitepoint in argyll (like with no
-t) would give me the max gamut volume, but maybe I should try factory
default rather than sRGB.
The problem with LCD displays is again and again that one does not know
what the controls and presets really do. Factory defaults are indeed
often a good starting point. At least the shape of one of the gamuts you
have posted does not look sane (rather a plateau on top, instead of a
peak) - I guess that some clipping was in the play here. If you anyway
want to calibrate and profile the display, then I'd rather suggest not
to enable an emulation mode like sRGB, where the monitor will do an
additional (unknown) color transformation internally (which can only
reduce, but never increase its native gamut). Rather try to operate the
display as native as possible [I'm not cursing functionality like sRGB
emulation mode in general, some high-end display do this job pretty
well, emulating a nearly perfect virtual sRGB display, but some
consumer-grade displays rather don't].
Regarding color temperature: The (absolute) chromaticities of the
display's RGB primaries are fixed and you can't change them. The only
thing you can change is basically the whitepoint (i.e. the intensity
ratios between the three channels). Assuming a white point relative
transformation from sRGB to the display color space, there will
certainly exist an "optimal" display white point which will maximize the
intersection between the white point adapted sRGB gamut and the gamut of
the display - but you have to find it (and you'll have to define in
which color space you want to maximize the intersection, since this will
give different results). Also note, if the display white point deviates
too much from the blackbody or daylight locus, then (depending on the
viewing environment) your eyes may no longer be able to adapt well
enough to the display white point and you may perceive "white" as
green-ish or magenta-ish, which will constrain the choice of the white
point additionally.
Regards,
Gerhard
