OTHER TECH

The big problem with LCD monitors is low contrast - the range (expressed as a ratio) between the brightest white and darkest black the display can produce. Since some light always makes it through the LCD panel to the screen, black areas of the picture appear dark gray instead of black. While a contrast ratio of 800:1 is common among the best CRT projectors, even the best LCD projectors can't achieve half as much. Another problem sometimes found is the "screen door effect," where the spaces between pixels in the panel appear as a faint grid overlaying the image. Many LCD projectors also lack the processing power to cleanly convert ("scale") the resolution of the incoming video to match the pixel count of the LCD chip or to realize fine gradations in color.

Projectors designed specifically for home theater overcome many of these limitations. In addition to standard A/V connections (often at the expense of computer connections like a VGA input) and better internal processors, they generally have reduced brightness and higher contrast to achieve better blacks. Many also employ 16:9-shaped panels to correspond to wide projection screens and widescreen DVDs and HDTV programs. While these advances are significant, video experts agree that both CRT and DLP (Digital Light Processing) projectors still beat LCD in the picture-quality race. In most cases, though, LCD projectors are cheaper.

LCD technology can also be built into rear-projection TVs. While still uncommon compared with CRT-based RPTVs, large-screen LCD models from Sony and Panasonic are beginning to appear in A/V showrooms. Their biggest advantage is their shallow cabinets. Sony's 60-inch KF-60DX100 HDTV monitor ($8,000), for instance, is a hair over 15 inches deep, or about 10 inches less than the slimmest comparable-size CRT rear projector. Like LCD front projectors, LCD RPTVs suffer from relatively low contrast, and they're still expensive. On the plus side, they don't require periodic tube convergence to maintain a sharp picture.

Perhaps the most exciting application of LCD is for ultra-thin direct-view TVs. These super-slim sets can be picked up and carried from room to room or hung in places where a normal set won't fit. Some direct-view LCD screens, like those on battery-powered Watchmen, portable DVD players, or the backs of airplane headrests, have narrow viewing angles - the image gets quite a bit darker and the colors less accurate as you move to either side of dead center. This isn't a problem for computer monitors and personal TVs, but a living-room TV requires a wide viewing angle so everyone in the room can enjoy a good picture. Advances in the way the liquid crystals are oriented allow better LCD sets and monitors to boast viewing angles up to 170°, which is comparable to a direct-view CRT set. New LCD TVs also have improved contrast (though still not as good as CRTs) and use significantly less power.