Re: [Frameworks] Quo Vadis Celluloid?

From: David Tetzlaff <>
Date: Tue, 23 Aug 2011 12:08:51 -0400

Color wheels only exist on one-chip DLP projectors. All one-chip DLP projectors I have seen produce an annoying momentary rainbow moire pattern from time to time, due to the color wheel. I find this completely unacceptable. There are different designs of color wheels, some with more segments than others, and some claim to eliminate the moire effect. I went to great lengths to actually find one of these I could look at: it still made the moires.

A three chip DLP generates all three primaries all the time, has no color wheel, and thus no moire patterns. I don't know what would happen if you put a shutter in the optical path of a 3-chip DLP. On the downside, you'd lose a fair amount of light. But it would be an interesting experiment to see what effect flicker has in and of itself, isolated from the other properties of film.

Most video projectors out in the world are based on LCD technology, and are designed more for data display than moving pictures. LCDs are bright, and can produce vivid colors: generally TOO vivid. If you go into a big box store and look at the wall of digital TVs, they're usually using some kind of Pixar-ish animated film as a demo. That's because the LCDs make live action footage look awkwardly cartoonish, but just give the cartoons more 'pop'. They have very poor contrast range, and most of them can't handle monochrome at all.

They'll never fix the color-wheel problem, so the hope for the future of digital projection is that 3-chip DLP technology gets brighter and cheaper, and LCD technology gets more accurate color reproduction and more dynamic range. There's been some movement in those directions, but not that much.

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Received on Tue Aug 23 2011 - 09:09:11 CDT