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. Even an ordinary 32-inch CRT-based television is a major hog, weighing well over a hundred pounds and requiring a couple of feet of space behind it. As a result, flat-panel displays have sprung up as a popular alternative.

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 has narrowed considerably. There are differences between plasma and LCD TVs that you should consider before purchasing one or the other, however.

You can find the latest prices on both plasma and LCD TVs in PC World Shopping.

Plasma

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. Essentially all current plasma displays offer HDTV resolution, as well. Screen sizes start at 42 inches diagonal and range up to more than 70 inches. Prices start at around $1000 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 $999 42-inch display that you would from a same-size model selling for $2000, a more typical price. The budget model will usually have lower contrast and poorer reproduction of black and of dark grays, yielding a picture with less punch and detail; in addition, it may do a worse 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.

The most expensive plasmas in a given screen size are typically the new 1080p models, which offer 1920 by 1080 resolution. Whether this provides a visible improvement in picture quality over lower but more typical plasma resolutions, such as 1366 by 768 or 1024 by 768, depends on screen size and viewing distance. The smaller the screen, the closer you must be to it to see the benefit of a higher display resolution. For example, with a 50-inch screen you would have to sit within about 10 feet to perceive the difference between 1080p and 1366 by 768.

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 most plasma displays now come with speakers that can attach to the sides or bottom of the panel, 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.

You can find the latest prices on plasma TVs in PC World Shopping.

LCD

LCD screens range from 15-inch models (or sometimes even smaller ones) designed primarily as computer monitors up to 70-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 $600 to $2000 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.) LCDs are now price-competitive with plasmas at screen sizes smaller than about 50 inches. For larger displays, LCDs are usually more expensive, though the gap is narrowing.

Despite great progress, LCDs still tend to 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, which can sometimes cause blurring of fast-moving action, such as in sports. However, LCD makers have made strides in this area as well, quickening response times and, most recently, introducing high-end models that refresh the display 120 times per second instead of the standard 60. This is done by interpolating between frames to create new frames with pixels illuminated at levels intermediate between those of the preceding and succeeding real frames--in other words, by faking it. But if done well, it can be a very good fake that improves the viewing experience.

LCDs are often 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.

You can find the latest prices on LCD TVs in PC World Shopping.