QUOTE (DDAVIS @ Jul 22 2008, 11:04 PM)
Well, yes, but it seems to me I can look at my photos made at Monument Valley and judge which ones have a more realistic color balance, etc. even though the monitor is far removed from solar illumination brightness levels. Are you saying I would need a carefully color balanced transparency, placed on a white 'light box' with enough brightness to register the same on a light meter as a white paper in daylight would, to resonably accurately show the colors of a sunlit surface? Or perhaps a projector as bright and color balanced as sunlight?
It's levels-on-levels complex!
In principle, any change in illumination is a deviation from accuracy in and of itself. But certainly we look at photos all the time, on photo paper, in books, and on monitors, that don't utilize sunlight-brightness, and still look OK.
The two biggest added variables are:
a) Perceived color balance is a function of illumination, even if the color mix of the light source is held absolutely constant.
Dark/light adaptation, which is something the retina and the pupil are both involved in.
I guess on one level, you can say that the complexity of light/dark adaptation makes it an easier problem to solve because you can say you did it if you even match one of the real situations.
And I think the other problem, perceived color balance vs. illumination, can basically always be solved for with *some* tweaking of the actual balances in the display. If dimmer screens make things seem bluer, then decreasing the blue should compensate for it and give you the "same" perceived hues with less illumination. I guess the question is how to arrive at that. Just to show how dastardly the whole situation is, I'm certain that the solution would be different for the fovea than for the perifoveal field of vision. So a 60-pixel image of Mars might actually call for different balance than a 600-pixel image.
As much as we all love science, it might really be just as well to tweak it to the approval of people who've seen it with their own eye. Although if we lock down a specific situation we want to capture (eg, an eyepiece view of Mars), then there ought to be a way to derive the correct balance with the right human performance information, trying to produce the same response ratios for all of the cones.