A TV for Every Type

Though daunting at first, the variety of new TV types ultimately means better choices for you and your wallet.

Sean Captain

Ah--remember the good old days of television shopping? You walked into a store full of boxes with flickering screens; some even had swanky, wood-grain finishes. If the salesperson asked you what kind of TV you wanted, you would answer with a size, or maybe a brand.

Today, if you walk into an electronics superstore, you face an army of glowing screens that differ far more than their predecessors. Some are enormous and require several strong people to move them; some are dazzlingly flat and can hang on a wall. Some are squarish; some, rectangular. And prices fall all over the map. With so much variety, how do you decide which TV to choose?

Luckily, I'm here to help. Before you take the plunge and buy a new television, you should understand the different types of technologies and what to look for when you make a purchase. I'll explain the four major TV technology types and their advantages and disadvantages in terms of picture quality, size, and price. Ultimately, today's abundance of choices gives you a lot more flexibility in picking the TV that's right for you and your budget.

Today's TV sets also accommodate different kinds of TV broadcast formats: high definition and standard definition. But we'll get into that later. Let's start with the different screen types and how they work.

CRT: This Is Your Father's Television

CRTs are the boob tubes we all grew up with (and many of us still have). Once you understand how a CRT works, it's pretty easy to understand the other TV types and decide what kind to get.

CRT stands for cathode ray tube. A CRT TV (or computer monitor, for that matter) works by allowing a beam of electrons to flow from the negatively charged cathode (sometimes called an "electron gun") at the back of the picture tube to the positively charged front. When that beam gets to the front, it hits a phosphor coating, causing the phosphors to glow.

Electromagnets wrapped around the tube bend the cathode ray so that it sweeps a line of individual points (called pixels) across the uppermost edge of the tube. Then the magnets bend the ray so that it sweeps another line just below the first one, and so on and so on until it has "scanned" lines of glowing pixels from top to bottom. A CRT television runs through this process about 30 times per second, allowing it to show a rapid succession of images that simulates fluid motion.

Now, what about color? Color CRT TVs have three types of phosphor: one that glows red, one that glows green, and another that glows blue. Varying the intensity of the three colors in each pixel allows the TV to create images with a broad range of colors. This basic idea of mixing red, green, and blue light is the principle behind all television types.

Old as color CRT technology is (dating back to the 1950s), it remains quite good for many reasons. First of all, it's cheap. Companies have been making CRT televisions for decades, and they have gotten very efficient at it. Today, you can buy a fine traditional CRT TV, such as the 32-inch Sony WEGA KV-32FS120, for $600.

CRTs also have some display quality advantages. For one, they produce very rich colors and a deep shade of black. And the slightly "soft" look of glowing phosphor actually hides some of the static and imperfections in a television signal or even in DVDs.

CRT Disadvantages

Two big drawbacks of CRTs are size and weight--which will come as no surprise to anyone who has had to move a big TV. Cathode ray tubes are heavy. (In fact, they contain lead!) And as the screen gets wider, the tube gets deeper. Plus, the screen dimensions are limited by the difficulty of making tubes beyond a certain size. Sony makes one CRT, the KV-40XBR800, that measures 40 inches diagonally. Companies including Sharp and Toshiba stop at 36 inches. And Samsung stops at 32. So if you want a really big screen, a really thin TV, or both, you'll have to opt for one of the newer TV technologies.

A subtler drawback to CRTs is a slight flicker. With cheaper (older) CRT TVs, by the time the electron gun is scanning the bottom part of the screen, the top portion is already starting to fade. To minimize the effect, such sets interlace their images--lighting every other line first (for example, lines 1, 3, 5, and so on) then going back and filling in the missing lines (2, 4, 6...). But interlacing poses a problem with motion. If an object is moving quickly across the screen, one set of lines will appear a bit farther ahead than the other, leading to a slightly jagged or sawtooth appearance.

Luckily, today's picture tubes can scan much faster and don't need to interlace images, but interlacing is built into the traditional television broadcast standard.

So, when is a regular CRT television a good choice? I recommend it for people on a budget who watch some regular network television and an occasional DVD in a medium-size living room or den. If you're not a TV and movie fanatic, there's no sense in spending a fortune on a TV using one of the fancy newer technologies. And a good CRT will still provide nice picture quality. If space is cramped, you might do better with a medium-size LCD TV (which we'll talk about in a bit). If you have a really big room, or you're a TV lover who just wants a big screen and you don't mind spending a fair amount of cash, you'll want to look into one of the newer technologies, such as plasma.

Plasma: Big and Flat

If you've seen a really big TV hanging on a wall, say at a sports bar, you were probably looking at plasma. Like CRTs, plasma TVs form images with pixels of glowing phosphor. But instead of using a cathode ray to energize phosphors on a screen, these TVs use hundreds of tiny cells containing gas that can be electrically charged into plasma, a high-energy state of matter.

By getting rid of the tube, you get a much thinner screen. New plasma TVs can be as little as 4 inches deep. And unlike tube TVs, they don't get any deeper as the screen gets bigger. Plasma TVs of 60 inches are now becoming common, and bigger ones are on the way. In fact, there is no such thing as a small plasma TV: You won't find one under 40 inches.

Plasma has the same good points that CRTs have in terms of image quality. On a decent plasma TV set, colors are very rich, and black is deep. Plus, plasma TVs are brighter than typical CRTs--allowing them to display richer images. That brightness, and the strong dark shades, lead to high contrast--a broad range of brightness levels that helps to bring out details.

What's Not to Like?

But plasma does share a major downside with CRTs: image burn-in. Have you ever noticed "ghost" images on an old CRT, such as the faint outline of the main menu that persists on an ATM screen? If a CRT or plasma displays the same image for an extended period of time, it will leave a lasting mark on the screen. This happens because phosphors take a beating every time they get hit with electrons, and over time, this changes how they look.

If you don't vary what you display on screen, the phosphor will age unevenly, with certain parts being lighter and others darker. So plasmas and CRTs are not ideal for viewing images with static elements, such as video games with panels that show your score, news channels that display stock tickers, or stations that always show their logo in the corner of the screen. That doesn't mean you can't watch this content at all--it just means you can't do it all day, every day, without risking burn-in on a plasma TV. Variety is the spice of life, and it will extend the life of plasma and CRT screens.

You can also fight burn-in, and preserve your TV, by turning down the brightness. Reducing it from 100 percent to 90 percent or lower will reduce the wear and tear considerably, and it will probably yield a better screen image: Too much brightness makes colors appear faded. But no matter how careful you are, plasma will not last as long as some other TV types, such as LCD.

Ultimately, plasmas are all about size. They provide a very big, very thin screen. But you pay a premium for those features. Plasma TVs start at 42 inches; at that size expect to pay between $3000 for entry-level models like Gateway's Ultrabright Plasma TV and $10,000 for high-end models such as Pioneer's PDP-4340HD.

LCD: Flat Screens in Many Sizes

LCD televisions are very similar to the flat LCD panels that come with newer desktop computers and on all laptops. Like CRT and plasma TVs, they also have pixels with red, green, and blue elements. But instead of forming images with glowing phosphor, they do it by passing light through red, green, and blue filters.

LCD stands for liquid crystal display. These liquid crystals have two important properties. First, they will completely block light when they face one direction and allow it to pass through when they face another. Second, they change direction when an electrical charge is applied. By varying the electrical charge, LCD TVs can adjust the position of the liquid crystals and regulate how much light passes though each color filter in the screen.

Though the mechanics are different, the net effect of an LCD is very similar to that of plasma--a flat panel that produces bright color images. In fact, it's not always easy, at first glance, to tell the difference between plasma and LCD panels of the same size.

But here's the rub: So far, LCDs have not been able to keep up with plasmas in size. While plasma models of 50 inches and greater are easy to find in stores, LCD TVs just recently passed the 40-inch mark. (Companies including Samsung, Sony, and Sharp now sell such models.) And inch for inch, LCDs are still more expensive than plasmas. While LCDs over 40 inches are cutting edge and cost $10,000 or more, comparably sized plasmas are commonplace, and many sell for about half as much.

The Downside?

Traditionally, LCDs have suffered from three weaknesses: slow response time, narrow viewing angle, and poor representations of black. Slow response times cause images of fast motion--in video games or action movies, for example--to appear slightly smeared or blurry. Newer LCDs have far better response times, however, and the fast-image problem has mostly disappeared.

Viewing angle is a harder problem to crack. Because of the way light is directed through LCD panels, they look best when viewed straight on. As you move to the side, or up or down, you lose a lot of the light, contrast, and image quality. Clever screen designs have greatly diminished this problem on newer LCDs, but they generally still don't match the full viewing angles of plasma and CRT.

Nor do they produce deep black as well as other technologies. The liquid crystals in LCDs act like a little valve controlling how much light gets through, and it's difficult to close these valves completely. As with response time and viewing angle, LCD makers have made tremendous progress with black levels, but they still trail the competition. A pitch-black shadow on a CRT or plasma may only be dark gray on some LCDs.

Which LCD TV to Choose?

Experts expect LCD TV prices to drop considerably in the next one or two years, however. So if you love the look of a big LCD and you're not in a hurry, you might want to wait a while.

If you're looking for a smaller TV, you can find good deals right now. While models bigger than 40 inches are over $10,000, 36- and 37-inch models may sell for about $5000, and 30-inch screens run as low as $3000. Though not as spectacular as giant screens, TVs in the 30- to 37-inch range are fine for many living rooms. Examples include Philips's 30-inch 30PF9946, Samsung's 32-inch LT-P326W, and Sharp's 37-inch LC-37G4U. For more on buying a flat TV, see PC World's "How to Buy a Flat-Screen TV."

Even for today's biggest LCDs, the price difference with plasma narrows when you consider the entire life of the TV. Liquid crystals and color filters don't wear out the way phosphor does. So LCDs will last longer than plasma and continue to provide top image quality for years. LCDs also use less electricity. A 42-inch LCD uses up to 240 watts, while a 42-inch plasma may consume about 400 watts. That difference will add up on your utility bills over time. And as a final bonus, image burn-in doesn't occur with LCDs. You can watch whatever you want, as long as you want.

Rear Projection: Bigger Screens, Smaller Prices

Even with all the advances in plasma and LCD technology, the biggest screen is still the silver screen. Getting the same effect in your house is possible--and increasingly affordable. But using a projector and a screen means watching TV in the dark, perhaps having to set up the projector in the middle of the room, and being careful not to walk in front of the light beam.

Far more convenient for most people is a rear-projection TV, which shines an image onto the back of a translucent screen. These TVs are boxier than plasma and LCD panels but far skinnier than CRTs (despite having larger screens). Some rear-projection TVs are as large as plasma models, but they are far less expensive than plasmas of the same size. For example, Samsung's 50-inch HLN5065W projection TV sells for about $3300, while the company's 50-inch HPN5039 plasma television sells for about $5500.

In a sense, rear-projection TVs have mini-versions of other TVs inside them. The oldest type, for instance, uses CRTs to project images onto the screen. The tubes are smaller than those in an old-fashioned CRT television, however, because the image is magnified by a series of lenses and mirrors before it hits the screen.

CRT projection TVs have a bad reputation because older versions were quite bulky, not very bright, and hampered by screens with very poor viewing angles. You might not see anything if you sat too far off to the side.

Today's CRT projection TVs use far better screens and brighter, smaller tubes. In fact, many purists consider them to be the best type of projection TV. And they tend to be less expensive than other types of projection TVs. But they are still bulkier and heavier than TVs that project light through LCD panels. Also, like standard TVs, rear-projection CRT models are subject to burn-in, while LCD projection TVs are not.

Mitsubishi and Philips, for example, make CRT projection TVs. Panasonic and Sony make both CRT and LCD projection sets.

New Technology

The newest projection TVs use technologies called DLP and LCOS. They are about the same size and weight as LCD projection TVs, and they are also free from image burn-in.

DLP, short for digital light processing, uses a small panel made up of hundreds of thousands of microscopic mirrors. Each mirror can move to one of two positions: one that reflects light onto the screen and one that does not. The more often a mirror reflects light onto a pixel, the brighter the pixel will appear on the screen.

See the DLP Web site for a great interactive demo of how the technology works. Major makers of DLP TVs include Gateway, LG Electronics, Optoma Technology, Samsung, and RCA.

LCOS, or liquid crystal on silicon, TVs are something of a cross between LCD and DLP projection TVs. Instead of reflecting light off moving mirrors, they send it through an LCD with a mirror behind it. LCOS TVs are still pretty rare, so it's hard to say how they will compare with other projection televisions. But they should become more common in the next year. Philips, for example, sells a 62-inch LCOS TV, the 62PL9774, for about $4700. It measures about 18 inches deep.

Projection TV Limitations

Regardless of technology, all projection TVs share some weaknesses. Viewing angles can be tight. You will notice a difference in screen quality when you move to the side or up and down. The difference is more pronounced than you'll see on newer LCD panel TVs, but much less noticeable than on older projection TVs.

Though they are much brighter than their predecessors, today's projection models still don't do well in brightly lit rooms. They look quite good, however, in a slightly dimmed setting.

If you can live with these fairly small drawbacks, plus the slightly thicker profiles, projection TVs are nice (and very affordable) alternatives to flat-panel LCD and plasma TVs. For more on buying a rear-projection TV, see PC World's "How to Buy a Rear-Projection TV."

HD, or No HD?

Now we get to the topic of high-definition television. The most important characteristic of HD is that it shows more detail, called resolution, than regular television. The standard TV format we've had all our lives uses a picture made up of 480 lines. High-definition television signals use either 720 or 1080 lines, so they can show finer details (sometimes even the pores on someone's face) that are lost in the 480-line resolution of standard television.

HD images are also wider. Standard TV pictures are 4 inches wide for every 3 inches tall, a proportion called a 4:3 aspect ratio. HD images use a 16:9 aspect ratio, similar to that of most films in movie theaters.

Most LCD, plasma, and projection TVs are built with HD in mind, so they have 16:9 wide screens. But they all offer modes that allow you to watch standard TV, either by stretching the image to fill the wide screen or displaying it unaltered in the middle of the screen.

As the old standby technology, most CRT TVs have screens with a 4:3 aspect ratio. But wide-screen, high-definition CRTs are available. They are more expensive than 4:3 CRTs of about the same size, but they are still less expensive than LCDs, and many videophiles contend that they offer the best image quality of all televisions.

And CRTs are the most economical. Take, for example, Sony's lineup of different TV types. Its top-of-the-line high-definition CRT, the 40-inch KV-40XBR800, sells for $2500. Its 42-inch LCD projection TV, the KF-42WE610, sells for $2800; its 42-inch plasma, the KE-42M1, sells for $4500; and its 42-inch LCD, the KDL-42XBR950, sells for $10,000.

HDTV also happens to use digital signals. But all digital TV is not HD. In fact, cable and satellite companies have long used digital signals to deliver standard TV programs more efficiently. A receiver box converts the digital signal to analog before it enters a standard TV. In the near future, all television broadcasts--both standard and high definition--will be digital. The Federal government requires a switch from analog to digital by the year 2007 (though it is unlikely that all broadcasters will meet the deadline, and extensions will likely be granted). To continue working, older analog TVs will need digital-to-analog converters, similar to today's digital cable boxes.

Just as all digital broadcasts are not high definition, neither are all digital TVs high definition: Many smaller LCD and plasma panels have only 480 lines and are called enhanced definition televisions, or EDTVs. If you see two LCD or plasma TVs with the same size but very different prices, the cheaper one is probably enhanced definition. Take, for example, two 42-inch Gateway plasmas. The EDTV Ultrabright Plasma TV sells for $2400, while the HD-Ready Plasma TV sells for $4500.

For more information and advice on high definition, see PC World's HDTV Answer Guide.

Final Advice

So, what should you do? If TV means a lot to you, skip the standard 4:3 CRTs and LCDs and get a wide-screen model, preferably a true HD version, be it CRT, plasma, LCD, or projection. The 16:9 screens are better for presenting DVD movies in their original wide format. With any of these sets, you can still watch standard television, and you are equipped for the ever-growing assortment of HDTV programming. Plus, getting a digital HDTV set will ensure that you can still receive all types of programming when broadcasters switch to digital transmission in the next few years.