Flat-panel LCDs have replaced bulky CRT monitors on the market.

In computer monitors as in TVs, models using LCD technology are becoming bigger, cheaper, and more dominant in the marketplace. Industry watchers report that the vast majority of monitors sold in the past year were lightweight, flat-panel LCD displays. They've almost entirely replaced heavy CRT displays, which took up much more desk space.

Along with the trend toward thin displays, there's a move toward bigger screens. You'll find more LCD models with screens 19 inches and larger. Most of the larger LCD displays have the wide-screen shape that's increasingly familiar from high-definition TVs. A large, wide screen is handy for many uses, including watching DVD movies, viewing and editing photos, running multiple programs, surfing the Web, and playing video games.

Prices continue to fall, even for LCDs with bigger screens. If you're buying a monitor bundled with a new computer, as many consumers do, you can often upgrade from the standard display to a larger one for a modest amount - $50 to $150 or so.

WHAT'S AVAILABLE

Apple, Dell, eMachines (which merged with Gateway in 2004), Gateway (purchased by Acer in 2007), HP (which merged with Compaq in 2002), Lenovo, and Sony all market their own monitors for their computers. Other brands of monitors, such as Acer, BenQ, Envision, KDS, LG, NEC, Philips, Planar, Preview, Princeton, Samsung, ViewSonic, Westinghouse, are sold separately. Many of those companies don't make their own monitors but buy them and put their own brand label on them.

With an LCD monitor, the nominal image size and the viewable-image size (VIS) are the same. That sets them apart from CRT monitors, which offered a bit less screen space than the size suggested. Desktop LCDs that measure 17 or 19 inches diagonally weigh around 15 pounds, compared with 30 to 50 pounds for a CRT. LCDs with a screen 20 inches or larger are increasingly available. Wide-screen LCDs, specially designed for watching wide-format videos, are also available. Those screens have an aspect ratio of 16:9, similar to what you'll find with most digital TVs.

Flat-panel displays deliver a very clear image but have some quirks. Their range of color is a bit narrower than a CRT's and you have to view the screen straight on to get optimal image quality. On some models, the picture can lose contrast as you move off-center, and fine lines might appear grainy. That's an issue if several people will be looking at the screen simultaneously. It's not a big concern if one user is sitting directly in front of the display. But most LCD monitors in our recent tests had a wider viewing angle than we've seen in the past.

Price: $150 and up for a 17-inch; $200 and up for a 19-inch; $250 and up for a 20-inch; $300 and up for a 22-inch; $500 and up for a 24-inch.

FEATURES THAT COUNT

A monitor's resolution refers to the number of picture elements, or pixels, that make up an image. More pixels mean finer detail. Most monitors can display at several resolutions, generally from 640x480 to 1920x1200 depending on the monitor and the graphics card. An LCD usually displays a sharper image than a CRT of comparable size when viewed at identical resolutions. But that's only if the LCD is set to its "native" resolution - 1024x768 pixels for a 15-inch screen; 1280x1024 (17-inches); 1440x900 (19 inches); 1680x1050 (22 inches); or 1920x1200 (24 inches).

The higher the resolution, the smaller the text and images, so more content fits on the screen.

Dot pitch, measured in millimeters, is the spacing between a CRT's pixels. If all else is equal, a smaller dot pitch produces a more detailed image, though it's no guarantee of an excellent picture. In general, avoid models with a dot pitch larger than 0.28 mm.

A CRT requires a high refresh rate (the number of times per second an image is redrawn on the screen) to avoid annoying image flicker. In general, you'll be more comfortable with a 17-inch monitor with a refresh rate of at least 75 hertz (Hz) at the resolution you want. For a 19-inch monitor, you might need an 85Hz rate to avoid eyestrain, especially at higher resolutions.

The refresh rate isn't an issue with flat-panel displays. Instead, you will see specs for response time, which indicates how well the screen can handle fast motion.

Monitors have controls for brightness and contrast. Most of them also have controls for color balance (usually called color temperature), distortion, and such. Buttons activate onscreen controls and menus.

Some monitors include a microphone, USB port, integrated or separate speakers, or S-video and component inputs for viewing the output of a VCR or camcorder. You might also see LCD displays with memory-card readers, so you can display photos on screen, and iPod docks enabling you to view images or play music through the monitor.

Plug-and-play capability makes it simple to add a new monitor to an existing computer.

Most new LCD displays have a DVI input, a digital connection required for use with certain video cards. You may need a $10 cable.

HOW TO CHOOSE

First consider an LCD monitor. A flat-panel LCD display would be a good choice for most users. It takes up less desk space than a CRT, uses less power, and emits less heat. You'll find a much wider selection of products to choose from than with CRTs, and prices are quite reasonable. CRTs deliver true color and render fast-moving objects well, so some users might want to consider them for photography and gaming.

Think big and go wide. For basic use, a 17-inch display is big enough, but if budget and desk space allow, we recommend a monitor 19 inches or larger. That's especially true if you work with photo enlargements or display multiple windows on the screen. Wide screens are handy for many applications.

Consider helpful features. One that allows you to adjust an LCD display's height is handy, as is the ability to tilt the angle of the screen. Some monitors can be rotated 90 degrees, from a landscape to portrait orientation, which can be handy for viewing photos, Web pages, and word processing documents. Also look for conveniently placed controls that adjust contrast, brightness, and other settings that affect images. We prefer a dedicated front-positioned control/brightness control.

Look for a long warranty. Many monitors, both LCDs and CRTs, come with a three-year warranty on parts and labor, but others have only one-year coverage. Although both technologies are well established and are usually not trouble-prone, it's worth looking for the longer coverage, especially if you're purchasing a more-expensive model.

Convergence with TV isn't here yet. Manufacturers offer monitors with TV tuners and LCD TVs with computer connections. But big differences remain between monitors and TVs. While both share LCD technology, monitors designed for computer use generally have a higher resolution than a TV with the same screen size, and thus can display computer content more clearly.

Computer monitors with built-in TV tuners cost $100 to $200 more than those without, and can't decode digital broadcasts.

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