How to Buy a Flat-Screen TV
The Big Picture
It's only natural that the supersizing of the American TV over the last decade or two would eventually spawn some diet programs. A 50-inch HDTV built in the traditional CRT-based rear-projection television format is a major hog, taking up a hunk of floor space and weighing hundreds of pounds. As a result, flat-panel displays have sprung up as a popular alternative to bulky CRTs.
Currently there are two kinds of flat-screen TVs: plasma and LCD. Both technologies have made it possible to build very shallow, relatively lightweight TV screens with large picture areas. Both carry higher prices than their bulkier brethren, as well, although the gap is narrowing in some cases. But there are differences between plasma and LCD TVs that you should consider before purchasing one or the other.
Plasma
Virtually all plasma displays are wide-screen designs, meaning they have a 16:9 ratio of screen width to screen height (also referred to as aspect ratio), which is the standard for HDTV and very close to the ratio used for most modern movies. This makes them more rectangular than the traditional, almost square 4:3 displays. Almost all plasma displays offer HDTV resolution, as well. Screen sizes start at 42 inches diagonal and range up to 61 inches, though screens as small as 37 inches and as large as 103 inches are available. Prices start at slightly less than $1500 and top out at more than $15,000.
You get what you pay for in plasma, which means you can't expect to get the same picture quality from a $1400 42-inch display that you would from a same-size model selling for $2500, a more typical price. The budget model will usually have lower contrast, yielding a picture with less punch and detail; in addition, it probably will do a poorer job of upconverting regular standard-definition (SD) TV programs and DVDs to its native resolution, which can result in a picture that looks softer, coarser, or noisier than it could with better processing.
Even the best plasmas do not quite match the ability of good CRT sets to reproduce deep blacks and gradations of dark gray. They're close enough now, however, that you probably wouldn't notice except in a direct comparison. Like CRTs, plasmas use phosphors to generate light, which means they can be subject to "burn-in." When a static image is left on the screen for a long time (a station logo or a text banner, for example), it may not completely disappear when the image changes.
This is particularly likely to be an issue if you watch a lot of standard TV programming on a wide-screen display or play a lot of games with static backgrounds. Fortunately, you can minimize the risk by keeping contrast and brightness settings reasonable (virtually all TV sets come out of the box with their contrast, brightness, color, and sharpness controls turned up too high) and by using stretch modes to fill the screen when you're watching 4:3 programming. In addition, most models now use pixel-shifting strategies that continually move the image on the screen in imperceptibly tiny increments to help prevent burn-in, with the result that this is much less of an issue than it used to be.
Although many plasma displays now come with wing speakers that can attach to the sides, or come with speakers built into the sides or bottom, some are strictly video displays with neither speakers nor any built-in TV tuner. In such cases you will need to factor those additional costs into your budget.
LCD
LCD screens range from 15-inch models (or sometimes even smaller ones) designed primarily as computer monitors up to 65-inch wide-screen designs complete with speakers and TV tuners. At screen sizes less than 42 inches, wide-screen HDTV LCDs have become increasingly price-competitive with similar-size direct-view CRT sets, though for the most part they still sell at a premium. A 32-inch high-definition LCD might range in price from about $800 to $3500 depending on its manufacturer and features. (A 32-inch wide-screen display has about the same screen height as a 27-inch TV with a conventional 4:3 aspect ratio.) In screen sizes where LCDs compete directly with plasmas, the LCDs typically are more expensive, with the gap rising as the screen size increases.
LCDs have lower contrast ratios than plasmas, primarily because they have a harder time reproducing deep black and dark grays. In addition, they have slower response times (though LCD makers have achieved significant improvements in this characteristic in recent product generations). They also tend to be one to several inches thicker than plasmas and have a somewhat narrower effective viewing angle. (Plasmas, like CRTs, are easily viewable from well off to the side and do not exhibit any change in brightness as you stand up or sit down.) On the other hand, LCDs are completely immune to burn-in, are easier to view in brightly lit rooms, and more often include all the standard features of a conventional TV. LCDs also run cooler than plasmas, minimizing the need for potentially noisy fan cooling. An LCD is a particularly attractive choice for a sunlit room or in situations where a plasma would be too large or where you want a display that can serve double duty as a TV set and computer monitor.
No comments:
Post a Comment