First of all, plasma TV sets are more vulnerable to phosphor aging than direct-view tube TVs. This is where image brightness degrades over time as the phosphors lose their light-generating ability. Phosphor "burn" is another potential pitfall, which is caused by the constant display of bright computer or video-game images in fixed positions over extended periods of time. These pictures remain as visible "ghosts" that never go away. Set the contrast at a decent, usable level, and hopefully you’ll avoid these problems. LCD (liquid-crystal display) TV sets, on the other hand, do not use phosphors at all, as the light source is a fluorescent panel behind a grid of liquid crystals. Image burn-in is not an issue. Dark shadows tend to be grayer on LCDs than they are on plasma or direct-view CRT (cathode-ray tube) sets, however.

Tube TVs can display images at factory-determined resolutions. Plasma and LCD TVs, by contrast, are fixed-pixel grid de vices that can display an image only at the panel’s actual, or native, resolution. This is an important specification, as sets that feature a lower pixel count than the original image can still deliver a good-looking picture but may sacrifice some detail to fit the picture to the panel’s native resolution. Sets with 480 vertical pixels will reduce HD (high definition) pictures to something roughly comparable to DVD quality, which can look fine but can’t be considered high definition anymore.

For compatibility with conventional and high-definition video sources, an internal scalar upconverts or downconverts all incoming signals into images that match the display’s rate. How well this is done is a function of the quality of the internal scalar and whether or not it features 3:2 pulldown and other picture-enhancing technologies. The 3:2 pulldown feature avoids creating jagged diagonal edges and other picture anomalies that might appear in movie-originated programming from DVD, regular TV, satellite or videotape. HDTV and progressive-scan DVD signals bypass the set’s 3:2 processor.

Displays come in two shapes, or aspect ratios: the familiar, nearly square 4:3 shape and the newer 16:9 widescreen shape. Since you’ll be living with your new set for a while (hopefully), I recommend choosing a 16:9 widescreen set, as most DVD movies and HDTV programs are or eventually will be presented in the widescreen format. However, Digital TV Editor Mike Wood points out that some 4:3 sets can display a 16:9 image (albeit with black bars at the top and bottom of the screen). This may be a better choice if the bulk of your TV watching is 4:3 programming, such as daytime TV and non-widescreen movies. Regardless, you’ll be watching a mix of 4:3 and widescreen 16:9 programs, so look for automatic 16:9 recognition, which detects widescreen-encoded DVDs and automatically switches to the correct screen shape. Sets with-out this feature require you to manually select the appropriate aspect ratio.

Peak light output and contrast ratio determine a set’s ability to put out a bright image, with sufficient difference between the brightest and darkest images to create a realistic picture. Choosing a TV based on quoted specs is tricky, since test methods vary and are impossible for you to confirm accurately. Let your eyes be your guide instead, and judge overall picture quality instead of obsessing over the various sets’ individual specifications.

A number of flat-panel sets lack broadcast TV (NTSC or National Television System Committee) tuners, let alone over-the-air digital tuners, while other sets are more fully equipped. If you have an external HDTV tuner box that has an analog TV tuner as well, you probably don’t need another tuner in the display.

The set’s complement of video and audio inputs and output connections determines how various signals get into and, to a much lesser degree, out of the display. A set with a full assortment of the various video inputs will ensure that you can connect your current and future source components. For regular signals, displays are usually equipped with S-video inputs, which feature a 4-pin mini connector, and the lower-grade composite video, which features a yellow-rimmed coaxial connector. Component video inputs use three separate video cables to provide better image quality than composite or S-video signals. Normal component connections accept only regular DVD players. Wideband component inputs handle both regular and progressive-scan DVD players and HDTV tuners. If you use a surround receiver or processor to switch between sources, you could live rather easily with a display that has only one set of each connector type.

Other less-common connections include RGBHV, which usually refers to a computer or HDTV video display input. This typically uses the familiar PC monitor–like, 15-pin trapezoidal-shaped VGA connector. In some cases, 5 coaxial inputs are grouped together using the twist-and-lock, pro-style BNC connector. What type of signals the connector will accept depends on the TV, so check the set carefully.

A VGA-type connector usually means that the TV will accept signals from your personal computer or PC-based game-box consoles. The 5-BNC connection might indicate HDTV acceptance. In many cases, a simple DB-15 VGA-to-5-BNC "breakout" cable can accommodate one signal or another, assuming the TV’s input can handle it.

Digital video connections are the newest way to transfer signals, and they allow video information to remain in digital form from the source component all the way to the display. This promises the sharpest picture possible from HD sources. FireWire, also known as IEEE-1394, is one version, and it also carries compressed signals from your digital tuner to digital recording devices like D-VHS or some future HD-compatible, recordable DVD. The digital visual interface, or DVI, is another connection that passes a digital signal but won’t connect to recordable devices. For compatibility, make sure the display’s DVI connection is also equipped with the HDCP anticopying encryption/ decryption system. HDMI (high-definition multimedia interface) adds encrypted digital audio streams along with the encrypted digital video information; is backwards-compatible with existing DVI devices; and will likely appear on DVD and HDTV components in the future.

Fortunately, there are numerous options to choose from when purchasing a TV set; however, you may not find a TV with all of the features discussed in this article. That being the case, get started by considering the ones that seem most important to you, and take it from there.

Related Product Directories:

 Plasma and LCD Displays
Rid yourself of that huge tube TV with one of these thin, flat panel TVs. Sizes, measured diagonally, range from 15-inch models in a 4:3 aspect ratio to 61-inch widescreen (16:9) plasma HDTVs.

 Direct View CRT Displays (27+ inches)
If you don’t need or can’t afford a flat panel, you can take comfort knowing that most CRT displays still look better. Here are listings of all the DTV-ready and integrated DTV models that are 27-inches and larger.