Sizing Up Your LCD TV

It takes more than a tape measure to tell if it's worth the price

IMAGE: Gene Blevins/Corbis

SEEING THE BIG PICTURE

Sharp’s mammoth 108-inch display could turn your garage into a drive-in movie theater.

Have you bought an LCD tele­vision in the past year or two? If so, you probably looked for the biggest screen you could get for your money. You might have paid a few more dollars for a brand you recognized or saved a few dollars by picking up a no-name television at Costco, so long as the size-to-dollar ratio was good.

But picture quality? Hey, all the displays in the store looked pretty good, as they cycled through images of swaying flowers or undulating fish. You might not have given it a second thought. Well, think again. Picture quality is fast replacing size and cost as the main competitive feature.

Liquid-crystal-display sets are widely available in sizes bigger than you’d likely ever want. Just how many people are going to have room in their homes for Sharp’s newest 108-inch model? (See http://www.lcdpreview.com/sharp.) At January’s International Consumer Electronics Show (CES) in Las Vegas, some observers seeing Sharp’s behemoth for the first time suggested that it might be considered a garage TV: you could park your car in the driveway and pretend you’re at a drive-in movie.

And the prices have fallen far faster than manufacturers ever expected, with large discounters that sell sets from Chinese manufacturers pricing 37-inch models at less than US $800 and 32-inch units at less than $600. Panasonic, Philips, Sharp, Sony, Toshiba, and other brand-name electronics companies have cut prices in response. ”For the first time, Black Friday was Red Friday,” Scott Ramirez, Toshiba’s vice president of marketing, told the CES press corps. Ramirez accused fellow manufacturers of following the Lemming Law—believing they could sell at a loss and make it up in volume.

Obviously, selling products below cost is not a strategy for the long haul. Manufacturers that have invested in expensive production facilities around the world cannot compete with low-cost Chinese manufacturers on price. So major LCD TV manufacturers are trying to compete, instead, on quality. Now that their new products are starting to hit store shelves, they hope you see the difference.

Seeing the difference is just what showroom demos have tried to thwart by favoring flower fields, tropical fish, and other static views. LCD technology has always had a few basic picture-quality problems, starting with poor contrast. The technology relies on a stack of color filters through which light passes. Each layer absorbs some of the light, reducing the difference between the brightest whites and the darkest darks. This problem does not afflict the old-fashioned cathode-ray tubes and plasma displays, whose individually colored phosphors create their own light (for a technical rundown, see ”Goodbye, CRT,” IEEE Spectrum, November 2006, at http://www.spectrum.ieee.org/print/4697).

LCDs are also troubled by ”motion blur,” seen in the snakelike trail left by a rocketing baseball or spiraling football. The blurring happens because an LCD turns on a pixel by shifting liquid crystals from one state in which they block light to another state in which they align to let light through. It takes longer for crystals to shift between the states than it does to hit a phosphor with an electron, as a CRT does.

At this year’s CES, nearly every mainstream LCD manufacturer fessed up to the problems, because—guess what—they’re all fixed now.

Here’s how they fixed them:

To increase contrast, companies are fiddling with the lighting, monitoring the incoming signal for brightness and adjusting the backlight accordingly. Together these measures produce as much as a fivefold increase in contrast, manufacturers say. Toshiba’s solution is called DynaLight. Panasonic calls its contrast improvement technology the Intelligent Scene Controller. For the longer term, many manufacturers are pinning their hopes on LED backlights, which can be dimmed in selected zones and—because they offer a purer light—lose less brightness to color filtering.

To reduce motion blur, manufacturers are adding processing power and increasing the refresh rate of the display. Televisions display a new image 60 times per second in the United States, 50 times per second in Europe. The new LCD TVs have doubled the rate, to 120 hertz in the United States.

To provide the viewer with twice as many frames as the broadcast signal encodes, the new televisions create extra frames. One cheap option is to insert a black frame in between the picture frames—which, in effect, turns the pixels off and makes them more like the phosphors of a CRT. This technique, however, cuts brightness.

But most of the premium manufacturers favor a more processing-intensive technique. The processor looks at two frames, interpolates the differences between them, and uses the result to create a third frame in between them. So, in the case of a baseball home run or a football pass, the ball itself will have a different position in the interpolated frame. The manufacturers are giving the trick different names. Sony calls it Motion Flow, JVC calls it Clear Motion Drive, Toshiba calls it ClearFrame, and for LG it’s TruMotion Drive.

Indeed, in the controlled demos at CES I could see a difference between old LCDs and new ones. But I’m always skeptical of such side-by-side demos, so I performed my own test. After looking at several new-tech LCDs displaying high-speed sporting events, and noting the lack of motion blur and high contrast, I took a walk—a long walk, as it turns out, because the no-name LCD manufacturers are in the cheap seats.

I went to those remote aisles and checked out demos from several Chinese manufacturers including Prima, the U.S. arm of Xiamen-based Xoceco, and Hisense of Qingdao. I figured the demos were tuned to best show off the products’ strengths, yet much to my surprise, I saw motion blur. So much, in fact, that though I’m typically a tight-fisted Costco shopper, I might consider paying a premium for my next TV. (I had a harder time judging contrast when the TVs weren’t adjacent.)

How much of a premium might that be? It depends on the resolution. Sets that offer 1080p (progressive) resolution display lines on the screen sequentially; those that offer 1080i (interlaced) resolution first ”paint” every other line of a frame before going back and filling in the missing lines. Interlaced pictures can seem to flicker; progressive displays don’t. Computer LCD monitors all provide progressive scan, otherwise it would be hard to read small text.

Other differences also complicate model-to-model comparisons. The number and type of input and output jacks vary. The boxes that hold the screen differ in styling. Some manufacturers skimp by not including tuners, reasoning that most consumers get their tuners from their satellite or cable providers.

But right now you can buy a 42-inch TV in the 1080i format from Olevia or Vizio for less than $900. This summer, 42-inch 1080p sets loaded with all the latest technology upgrades from major manufacturers will cost from $2000 to $3500, more than double the cost of the lower-tech no-name sets.

What should the consumer do? Paul O’Donovan, an analyst with research firm Gartner, suggests waiting. He says that by December, prices will fall by 35 to 40 percent from their January level, even as picture quality continues to improve.

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