LCD and Plasma screen televsions

Big screen entertainment at the lowest possible price

Introduction The sexiest thing going in TV is flat panels--plasma and LCD displays only a few inches thick. Finally, TV sets that can hang on walls. But if you don't care about that, is a flat panel still the best way to go? And if you definitely think that flat is where it's at, which is better, plasma or LCD? Here's what you need to know before you buy.

The Big Picture It's only natural that the supersizing of the American TV over the last decade or two eventually spawned some diet programs. A 50-inch HDTV built in the traditional CRT-based rear-projection television format is a major hog, taking up a big hunk of floor space and weighing hundreds of pounds. Of the publicious approaches to dealing with this problem, the one that has drawn the most attention is flat-panel display. Advances in plasma and liquid-crystal display, or LCD, technology have made it possible to build very shallow, relatively lightweight TV screens with large picture areas. That's their common advantage. Their principal common drawback is high price compared with bulkier alternatives. But they differ in enough other respects to make the choice between them interesting. 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. With a handful of exceptions, screen sizes start at 42 inches diagonal and range up to 61 inches. Prices start at slightly less than $3000 and top out at more than $25,000. You get what you pay for in plasma, however, which means you can't expect to get the same picture quality from a $3000 42-inch display that you would from a same-size model selling for $7000, a more typical price. The budget model will be an enhanced-definition screen rather than high definition and will have poorer contrast; that translates to a softer picture with less punch and detail. 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. Although some plasma displays come with wing speakers that can be attached to the sides, most are strictly video displays with neither speakers nor any built-in TV tuner. You will need to factor those additional costs into your budget. For more information on home theaters and speaker systems, check out "How to Buy a Home Theater System" and "How to Buy an Integrated Home Theater Audio System." LCD LCD screens range from 15-inch models designed primarily as computer monitors up to 37-inch wide-screen designs complete with speakers and TV tuners. Although not as pricey as plasmas, they still sell at a significant premium above what you would expect to pay for similar-size direct-view CRT sets. A 22-inch wide-screen high-definition model might come in at around $2000, for example, and a 32-inch model at close to $4500. (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 have lower contrast ratios than plasmas, primarily because they have a harder time reproducing deep black and dark grays. They also tend to be one to several inches thicker than plasmas and have a 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, and they 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 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. The Specs Explained Gone are the days when you figured out how big a screen you wanted, looked at some sets, and bought the one with the best picture that fit your budget. An options explosion has littered the shopping landscape with numbers, features, and terminology that even experts sometimes have trouble tracking. So we've tried to boil the choices down to the basics that can actually do you some good. (In audio and video, never forget that just because something has a number to describe it doesn't mean it really matters!) We've grouped the specs into three categories: important, somewhat important, and minor. Important: Contrast Ratio Contrast ratio refers to the brightest and darkest light values a display can produce at the same time. All else being equal, the higher the better. However, all else is seldom equal. Pumping up the maximum light output, for example, can increase contrast, but it won't do anything to overcome poor black level, which tends to be a greater problem with plasmas and, especially, LCDs. So take contrast ratings as a rough guide to be supplemented by eyes-on evaluation. That said, LCDs tend to have contrast-ratio specs ranging from about 400:1 to 800:1. Plasmas start at about 600:1, with the really good ones clocking in at 1500:1 or better. Important: Aspect Ratio The aspect ratio describes the relationship of screen width to screen height. Conventional sets have a 4:3 aspect ratio, whereas wide-screen models are 16:9. Wide screen is the future. HDTV is a wide-screen format, for one thing. For another, DVDs usually look better on wide-screen displays because nearly every movie made in the last 50 years was filmed in an aspect ratio of either 1.85:1 (very close to 16:9, which is 1.78:1) or 2.35:1 (even wider than 16:9). Important: Resolution Non-CRT displays, such as plasmas and LCDs, are fixed-pixel arrays, which means they have rows and columns of individual picture elements that turn on and off to produce the necessary patterns of light. Resolution is specified as the number of pixel columns by the number of pixel rows--640 by 480, for example, or 1280 by 720. Resolution and, to a somewhat lesser degree, contrast ratio determine perceived picture detail. Digital content currently is delivered in one of three formats--480p, 720p, and 1080i.The 480p format is typical of progressive-scan DVD-players; 720p and 1080i are used by satellite, cable, and over-the-air broadcast high-definition content providers, as well as some advanced DVD players. Generally speaking, a display is considered high definition if it is wide screen and has a total pixel count approaching 1 million. So 1280 by 720, 1366 by 768, and 1024 by 1024 are all examples of high-definition display resolutions. Small differences are not very consequential at greater than 1280 by 720, the specified resolution of the 720p high-definition format. Any resolution of 1280 by 720 or greater is best for viewing high-definition broadcast and DVD content. Non-HD wide screen is called enhanced-definition; a typical ED resolution would be 852 by 480. Standard-definition, or SD, would include 640 by 480 and 720 by 480. Enhanced-definition displays are best for 480p content such as progressive-scan DVDs. Important: Video Inputs The number and type of video inputs determine what sources you can use with the display. Composite video: Lowest quality but broadest compatibility. Any device that has video outputs will include composite video among them. Connection is made with a single 75-ohm coaxial cable between RCA jacks. S-Video: Better quality, and most video sources except standard VCRs now have S-Video outputs. Connection is made with a special cable and multipin sockets. Component video: High quality. This is the minimum standard for connecting HDTV tuners and progressive-scan DVD players. Requires three 75-ohm coaxial cables of the same type used for composite video. RGB+H/V: High quality. An analog red-green-blue horizontal/vertical connection is sometimes used instead of component video. This input requires five 75-ohm coaxial cables of the same type used for composite video. VGA: High quality. Video graphics array is an analog RGB connection used for computer connections and sometimes in place of RGB+H/V. DVI: Highest quality. Digital visual interface is a digital RGB connection, commonly used for HDTV tuners and occasionally for DVD players; it may also be used for computer connections. Requires a special cable and multipin sockets. Some displays with a DVI input may work only with computers, so watch out for that if you plan to connect an HDTV tuner. Another thing you need for guaranteed HDTV compatibility is compliance with the HDCP (High-bandwidth Digital Content Protection) system. HDMI: Highest quality. High-Definition Multimedia Interface is basically DVI plus a digital audio link and HDCP; it can be mated to DVI using adapter cables. This connection is used on some HDTV tuners. Minor: Comb Filter Type Comb filters are necessary in analog TV to separate color and luminance information without losing too much detail, but that's not an issue in HDTV. The only time the comb filter comes into play is for analog TV reception or any signal coming in via a composite video connection. For all other connections, it's out of the loop. Plus, the comb filters in flat-panel TVs are routinely very good. Topics > Electronics > Home Media Center > TV > How to Buy a Flat-Screen TV « Previous 1 2 3 4 Next »

Flat-Screen TV Shopping Tips Flat-out ready to buy? Here are key points to consider before you make the big commitment. Consider the alternatives: If you can live with a tabletop set that's 16 to 18 inches deep rather than 4 to 7, LCD and DLP (digital light-processing) rear-projection sets can deliver performance approaching or exceeding that of plasmas in similar screen sizes and at substantially lower prices. You just don't hear about them as much because they're not as sexy. To learn about other big-screen TV options, check out "How to Buy a Rear-Projection TV." Think DVI: If at all possible, you should get a set with an HDMI (High-Definition Multimedia Interface) or HDCP (High-bandwidth Digital Content Protection)-compliant DVI input. This will ensure full compatibility with HDTV tuners and future HD-DVD players. Compare displays using a publiciety of material: Just about any flat-panel display will handle HDTV and DVD signals well, but mediocre cable and satellite signals will give some of them fits. Don't make a buying decision based solely on pictures generated from pristine sources. Look for good blacks: When you're comparison shopping, bring along a DVD of a movie containing some dimly lit night scenes. Use it to check for good black reproduction and ability to render detail in near-darkness. Get to know the remote: A good remote can be your best friend, a bad remote your worst enemy. (Well, okay, we're exaggerating a little, but you get the idea.) Does it have backlighting or glow-in-the-dark buttons to help you see what you're doing when the lights are turned down? How easy is it to find commonly used buttons by feel? Check the video settings: Now that you've got the remote, pull up the video-adjustment menu and look at the settings. If you thought the picture looked a little (or a lot) off on first viewing, try selecting the median settings for contrast, brightness, color, tint, and sharpness. Those probably won't be optimum, but chances are they're closer than what you found originally. A good display can easily look worse than a lesser one if it's poorly adjusted. Repeat your tests using a publiciety of sources, including a dimly lit movie, if necessary