(Columbia) March 2, 2004 - A plasma screen is made up of thousands of pixels containing gas that's converted into "plasma" by an electrical charge. The plasma causes phosphors to glow red, green, or blue, as dictated by a video signal. The result: a colorful display with high brightness, even in light-filled rooms, and a wider viewing angle than most rear-projection sets and LCD (liquid-crystal display) TVs.Like CRT-based (cathode-ray tube) projection TVs, plasma sets are vulnerable to screen burn-in, and there are concerns about their life expectancy. Also, plasma sets run hot and consume more power than any other type of TV.
Prices have dropped sharply over the past year or two and now that companies such as Gateway and ViewSonic have expanded from the computer arena into TVs with aggressive pricing, prices should fall even further. You may want to wait if there's no urgent need to buy now. If you can't wait, here's what to look for.
HOW TO CHOOSE
Decide whether you want true HD or the next best thing. When buying a plasma TV, you'll face a choice between HD (high definition) and ED (enhanced definition) sets, which cost less. The two types differ in native resolution--the number of pixels in the display--a spec often listed in ads. All the tested HD sets have a native resolution of 1024x1024 except the Panasonic TH-42PX20, with 1024x768. The ED sets are 852x480.
Weigh screen size and configuration against price. If you're buying a plasma TV, an important question is how much screen can you afford. Generally, the bigger the screen, the bigger the price tag. You can easily spend $5,000 for a 42-inch HD-ready model, $10,000 for a 50-incher, and $20,000 for an HD-ready set that measures 60 inches or more.
Beware of burn-in and burnout. Plasma TVs are prone to burn-in of static images, much like CRT-based rear-projection TVs. Over time, static images from a video game or a stock ticker can leave permanent impressions onscreen, so minimize the risk as much as you can. You may have seen reports, in print or online, suggesting that plasma TVs may not last as long as other types of TVs. Some industry experts project 20,000 hours of use or more before a plasma screen loses half its brightness. Even in heavy use (40 hours a week), that's about 10 years. Overall reliability is a question because the technology is so new. The brand repair histories we have for other types of TVs don't apply to plasma sets.
Don't get hung up on specs. Ads touting high contrast ratios and brightness (cd/m2, or candelas per square meter) may sway you to one set or another. Don't pay much heed. Manufacturers arrive at specs differently, so they may not be comparable. Adjust sets in the store yourself to compare contrast and brightness.