Compression Technology

Posted on July 25, 2006 by Art Feierman

Compression Technology

How well a projector handles higher resolution source material is somewhat less important today than a few years ago. This is primarily due to how current Windows operating systems handle the output to external devices like projectors. In days gone by, a laptop would typically output it's native resolution to the projector, even if it wasn't a match. This forced the projector to rescale the image to reproduce it with less pixels than many higher resolution laptops that have native resolutions of SXGA+ or UXGA. More likely today, your laptop will output the projector's XGA, and resize the display on your laptop, to lower resolution to match. About the only time this is a nusiance, is when you are viewing spreadsheets, and end up seeing less columns and rows because of the lower resolution of the projector.

That said, the Dell projector re-produced very good SXGA+ (1400x1050) source material, and also performed well on UXGA (1600x1200). On the SXGA+, small type (8-10 point) on spreadsheets is very readable, with only minor softness and unevenness. UXGA was more problematic, still readable, but pretty "ugly". Of course reading 8 point type on UXGA, requires that you are probably in "the first row", so presenters are not likely to use type that small, except that labels on charts in programs like Powerpoint may default to that small a point size.

Overall Dell's compression handling is very good.

Basic Video Performance

Although we are really looking to determine how well the Dell performs on typical presentation video, and not how it does as a home theater projector, we were pleasantly surprised. For typical video performance was excellent, and extremely bright. Out of curiousity, I watched brief segments of two movies, The 5th Element from DVD, and Serendipity in HD-DVD, and was most impressed with how it performed as a bright home theater projector with about 3 times the brightness of a typical dedicated home theater projector (in it's best mode).

There was one significant weakness, though, (as a home theater projector, not for typical education/business videos). The 2400MP produces a noisy image. On large medium and brighter areas, you can definitely make out noise in the picture, and at times it is rather significant. This general noise - is visible particularly on non-motion shots, or where this is slow panning, but it's there all the time. Anyone fairly critical, will see it, and it really does make the 2400MP, less than desirable as a bright, affordable digital projector for home theater, which is too bad. Still some will find it acceptable, and it may well do very well for gamers, and possibly sports viewing.

I ran the HQV suite of tests on the 2400MP, and besides the very evident noise in the picture, it performed farily well on jaggie tests, and most of the HQV motion noise tests. So the problem relates to regular noise.

Note, it is still a 4:3 XGA projector, so it produces a lower resolution image (576p) than a typical widescreen home theater projector (720p), although higher resolution than entry level home theater projectors (480p) when watching normal wide screen movies. Considering it's low price, I wouldn't be surprised for it, despite the limitations, be a decent choice as a home theater projector for those needing a lot of brightness, although there are other business projectors less powerful, and similarly priced without a significant noise problem.

Overall I must describe the Dell 2400MP's video performance to be excellent for a portable business projector. This is one you certainly wouldn't mind doubling in your home for movies or sports, and it has the "horsepower" to deal with a fair amount of ambient light, but the high, visible, image noise in bright areas definitely diminishes it for the home roll. For occasional home use, just fine. As a bright home theater projector, you'll want one with less noise, even if it costs more.