Just a quick note on rainbows, and the LT150 in particular...
The human eye "strobes", that is, it vibrates back and forth, at around 200(?) hz. When test subjects had their eyes sedated, all they could see was a gray blur, _but_ while they moved their heads, vision returned. The cones apparently saturate when fixed with a steady source of fixed-wavelength light, so the strobing acts to clear them.
(This was from a Scientific American article from maybe 20 years back- I can easily be fuzzy on the details...)
When I feed a high contrast JPEG slide to the LT150, from either a computer (xga 75 hz.) or from the CF card, and jerk my head back and forth, I see rainbows. The image doesn't have to move, just my eyes. We did this test last Friday night, and four out of nine hot tub dwellers saw the effect.
My guess is that there is an interaction between the natural strobing of the eye, and the speed of the colorwheel. Some people are sensitive to it, as some people are sensitive to monitors "throbbing" under flourescent lights. And some are not. Changing refresh rates may help, as well as limiting extreme contrast ratios.
I see them, but they don't bother me. After the tests, we watched "Nightmare Before Christmas", and as in not thinking about elephants, after a while, not thinking about rainbows caused them to minimize.
Now, twenty years ago, there was a part of our population that would have said "I see rainbows! Groovy! Pass the pipe..." That was then...
apg