Axiom Home Page Forums General Discussion Home Theater A couple of front projection questions....

Hi Rick,

Just a comment in passing: Don't eliminate DLP front projectors from your consideration. In the various manufacturer demos I've seen, including Panasonics, I've generally found that the DLP front-projector images seem to have more "punch"--better contrast than the LCD front-projector images. It's a purely subjective judgment, but when I leave the Panasonic demo rooms, and they are quite impressive, and walk into an Optoma DLP demo room, there is something about the DLP image--the brightness and contrast--that I prefer. I used to criticize LCD projectors for the visible pixels, but with Panasonics, that's now a thing of the past, so it isn't that.

The old visible pixels, or "screen door effect" was from LCD projectors which shined the light through a panel. What you were seeing were the wires running to each cell of the matrix. Newer projectors use LCoS (Liquid Crystal on Silicon), these are chips which have the cells touching each other being controlled directly by the chip surface below them, thus no wires. But light can't shine through a chip, so the base of each cell is reflective so the light picks up a color as it bounces off the chip and out through the lens.

DLP is also mirror based (also called micro-mirror device), but each mirror can be moved by the chip below it. When the pixel is off the mirror reflects the light onto a black sink, when it's on it's out through the color filter and then through the lens. The problem I (and many others have) with single-chip DLPs is the filter is actually a wheel with red, green, and blue sections, which spins rapidly behind the lens. First the chip shows the red pixels while the red filter is there, and when it rotates to the green it quickly flips the mirrors to the green values, and so on. This is happening hundreds of times a second, so it shouldn't be visible. But peripheral vision is much more sensitive to movement, so I catch rainbows out of the corner of my eyes and I get sick in about 4 minutes of watching a single-chip DLP.

That brings out the 3-chip DLPs. They're pretty much the same, but there's a separate chip for each of the primary colors (RGB), and the filter is before a beam combiner (think prism), the combined beam then exits through the lens.

The 3-chip DLP is my pick for best looking projector of the current technologies. LCD or LCoS, just doesn't have the punch or depth, and the color-wheel based DLPs make me want to close my eyes and crawl away.

Panasonic does build 3-chip DLP, 1080p projectors. The PT-DW10000U and PT-DZ12000U fit the bill. But at around $40k to $50k, it's hard to imagine many people using them in their home theater.

I'll stick with my direct view plasma for now. Maybe the laser projectors will be cheaper, they should have a massive contrast ratio. The only thing I worry about with lasers, is their primary colors don't exactly match the hues selected by standards boards which were based upon phosphorescence of specific materials (which is why CRTs and plasma displays are the only technologies can be considered reference for color--but many makers don't use the exact materials anyway).