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Plasma or DLP: Sexy Versus Thrifty

Even turned off, almost any plasma TV looks cooler than a projection set. Ironically, these skinny sets have a lot in common with good old CRTs. Both form color pictures by illuminating combinations of phosphor dots that glow red, green, or blue. But instead of lighting phosphors with an electron gun at the end of a long tube, as CRTs do, plasmas use electrically charged gas--the plasma--in tiny cells, one cell for each phosphor dot.

Plasma TVs are so thin you can hang them like pictures. But they can weigh 100 pounds or more, so you need heavy-duty hardware (sold separately) and a good carpenter to wall-mount them.

Projection TVs all magnify a small image with lenses and mirrors and project it onto the back of a translucent screen. Older sets generate the image with CRTs; newer ones shine light through small LCDs or bounce it off mirrored, LCD-like chips called liquid crystal on silicon (LCoS). But the most popular projection technology today is DLP. A lamp shines light through a spinning wheel made up of red, green, and blue filters, producing color pulses that hit a chip containing nearly 1 million pivoting mirrors--one for each pixel on the screen. The more often a mirror pivots, the brighter the pixel will appear.

But the projector and mirrors take up space, so while DLPs don't weigh more than plasmas, they are taller and deeper (around 15 inches for our models). You can't wall-mount them, but on a table, they don't need more space than plasmas.

Viewing angle is a big differentiator between plasma and DLP. Plasmas look the same wherever you sit; DLPs lose brightness and contrast as you move off center. Our DLP sets retained good picture quality throughout a side-to-side viewing-angle shift of at least 90 degrees; the up-and-down range was tighter, so setting the TV at the right height for your viewers is key.

Another DLP problem is a rainbow effect. The pulses of red, green, and blue light come and go so quickly that you usually perceive them as appearing all at once. But you may occasionally see flashes of individual colors, especially in a very dark room. On the other hand, images on both plasma and DLP TVs suffer under intense light, especially direct sunlight.

Overall, plasmas have a slight edge in image quality, and their thin profiles give you more setup options. But DLP's disadvantages are not huge, and the lower prices are a big plus.

Also, DLPs age more gracefully. Phosphors on a plasma screen gradually lose brightness, and after brightness drops by about 50 percent, your TV image is only a shadow of its former self. But the vendors of our reviewed plasmas estimate so-called half-lives of between 20,000 and 30,000 hours for their screens. That's seven to ten years of watching TV 8 hours per day, every day--enough for even Law and Order junkies to keep up.

Beauty Fades

But some phosphors on plasma sets may fade faster than others, leaving ghostly patterns on the screen--an effect known as burn-in. If you're addicted to CNBC, the ever-present ticker tape at the bottom of the screen will eventually leave a mark--as will static elements in video games (such as boxes showing your score) or the blank panels you get when programs don't span the full width or height of the screen. You can still watch this content, but if any single one dominates you risk burn-in.

Some plasma TVs have tools to combat burn-in. An orbiter feature in the Mitsubishi and LG models slightly (and imperceptibly) shifts screen images back and forth and up and down. The inverse function feature in these sets reverses the colors of programs, much as a film negative displays light in dark areas and vice versa. This causes the screen to age more evenly, so patterns are less likely to persist.

You can break in a plasma screen by evenly burning off its first 5 percent of brightness; LG's plasma can display a pure white screen for this purpose. A professional installer should also do this (see "TLC for Your HDTV").

DLP sets don't suffer from burn-in, but their lamp bulb will certainly die. The vendors in our review estimate half-lives of about 8000 hours (2.7 years) for their bulbs; replacements run about $250 to $400 and you can install them yourself.

Both types of TVs are subject to defective pixels. Five manufacturers in this group provided a pixel-defect policy. The best was Panasonic's, which provides coverage if more than three pixels are defective. But Mitsubishi's guarantee that 99.99 percent of its pixels will function would allow up to 104 defects on the 50-inch TV's 1365-by-768-pixel screen. Most warranties provide coverage for only a year.

What's on Your HDTV?

Four models in this review--the LG, Panasonic, and Pioneer plasmas and RCA's DLP--are true HDTVs, with integrated ATSC tuners that can receive HD signals over the air. The other models are "HDTV monitors" or "HDTV-ready": They require third-party receivers for HD content (see "Getting Set for HDTV"). Except for the Mitsubishi, the other TVs have one or two NTSC tuners for receiving standard analog television. Because most television is still low-def and analog--and because even high-def channels broadcast a lot of standard-definition content (broadcasters simply upscale the 480 lines of these shows to HD's 720 or 1080 lines of resolution)--we included several clips of it in our tests. However, our test material consisted mainly of recorded off-air HD programs and two DVD movies. We strongly recommend using digital sources--via a DVI or HDMI cable--with your digital TV, but some cable boxes and most DVD players have only analog outputs. Component video is the best of these (see the Descrambler column this month for a guide to audio and video cables).

Color Conquers All

Color quality was the most important measure in our tests, and probably the area in which the TVs varied the most even after we calibrated each using Digital Video Essentials, a $25 tool on DVD.

Among the plasma models, Pioneer's PDP-5040HD took top honors for color, scoring 65 out of a possible 100 on our scale; the Mitsubishi PD-5030 was close behind, at 61. LG's plasma TV took some knocks for overblown colors. But Gateway's plasma is the real loser. While only 9 points separate the top-scoring Pioneer and the fourth-place LG in our color tests, 20 points separate the LG from the Gateway. Basically, images were the sickly yellow of photographs left in the sun for weeks. The Gateway also scored 11 points less than the LG in our brightness and contrast tests and in our judges' overall-impression rating.

Good performance, moderate price, a built-in HD tuner, and good control options earned the Panasonic our DW Value award. Among the projection TVs, the OptomaTV edged out the RCA, primarily for color quality.

Image quality and ease of use vary a good deal among today's plasma and DLP projection sets. But with proper upkeep, the latest high-end models will deliver big, beautiful pictures. So if you are ready to invest in a big, flat screen, one is ready for you.