This morning's WJI: (interesting reading material, posted
on Zenith's news thread)
<< Electronics:
Does Your TV Make You Squint? Here's the Reason
By Evan Ramstad
03/17/98
The Wall Street Journal
(Copyright (c) 1998, Dow Jones & Company, Inc.)
Does the world seem brighter on TV? Well, quite literally, it is.
Eager to catch shoppers' eyes, television manufacturers are shipping TVs from the factory with brightness and contrast set ultrahigh. At home, however, the color isn't true. To engineers and videophiles, the practice is an abomination that they deride as
setting the TV in "torch mode."
Viewers may hate the bluish tint the torch-mode setting gives to the TV picture, but they can't adjust it with a flick of the remote. In most cases, it requires a housecall from a technician who has to dismantle the TV and tinker with its electronic innards using sophisticated color analyzers.
Televisions that are too bright tend to cause viewer fatigue and eyestrain after an evening of channel-surfing. In addition, picture tubes that are forced to work too hard wear out faster and eventually produce an effect called "blooming," in which colors stray beyond the confines of their images.
"In audio, being accurate and true is something that's considered worth paying for,"says Joel Silver, a partner in Imaging Science Foundation Inc., a Boca Raton, Fla., consulting firm that trains TV dealers how to achieve color accuracy. There's no equivalent standard for TV color, he adds: "We haven't even started talking about fidelity in video."
But a backlash is brewing. The growing popularity of home theaters -- and the imminent arrival of digital TV and other fancy video electronics -- has made highend consumers far pickier about picture quality. People who spend as much as $300,000 on a home-entertainment center want nothing less than theatrical-movie quality from their $40,000 projection TVs.
Their demands are trickling down to the mainstream market. Some manufacturers are adding new controls to sets priced from $1,000 to $3,000 that allow consumers to tinker with arcane settings like "color temperature."
Color temperature is a way to measure colors in the light spectrum. It is expressed on a scale equivalent to the color of carbon as it is heated. (Think of a flame that turns from red to yellow to white to blue as it burns hotter.) Black is about room temperature, or 300 degrees Kelvin. In 1953, an industry group known as the National Television Standards Committee ruled that the color temperature of white on TV is 6,500 degrees Kelvin. Broadcasters and filmmakers still adhere to this standard.
But manufacturers have been steadily turning up the heat. Today's current-model TV sets sometimes have white color temperatures xceeding 16,000 degrees Kelvin.
All but a handful are set above 8,000 degrees Kelvin. Computer monitors, which mainly display stationary images, generally use lower color temperatures, though manufacturers like NEC Corp. offer some monitors with a range of settings.
TVs began getting brighter in the late 1960s, after Sony Corp. of Japan introduced a new tube technology in its Trinitron sets. Unable to immediately match Sony's picture quality, other manufacturers simply began raising color temperatures.
The higher color temperatures essentially change white TV images to a pale blue hue that the eye perceives as brighter. That's why a television set produces the blue glow when seen from outdoors at night. Raising the color temperature of white distorts other colors on the screen, making skin tones, for example, appear sallow.
"The idea of putting all this blue in the picture came about as a necessity to grab the consumer's attention," says Craig Eggers, director of product planning at Toshiba Corp.'s Toshiba America Consumer Products unit.
Russ Herschelmann, a home-theater designer in Napa, Calif., says the difference between torch mode and accurate settings is like the difference between cheap wine and fine burgundy. But he says "manufacturers don't necessarily want you to know about this."
Television makers insist they've been forced to raise color temperatures because viewers prefer watching TV in brightly lit rooms and they purchase TVs in stores lit up like gymnasiums. (In a bright setting, higher color temperatures help correct for picture washout by increasing the set's own output of light.)
Indeed, in a store display of TVs adjusted to maximum brightness, an ordinary set is an unlikely seller. "It doesn't look as bright," says James Whitfield, a customer at a Fry's Electronics store in Dallas, as he watches a $3,000, 32-inch Sony TV adjusted to the industry standard.
Once a customer brings an ultrabright set home, however, appointment with the picture can set in. Fiddling with the settings for color, brightness, contrast and tint don't affect color temperature.
The TV's color control adjusts the amount of color-just like the volume control, notes Mr. Silver of Imaging Science. "If there's an error in the color temperature, just adding more of all colors doesn't correct the problem," he adds.
Owner frustration has spawned a sideline business for TV dealers and custom electronics installers, who will calibrate sets for $100 and up.
On sets made in the last eight years or so, technicians use a special code on the remote to bring up on-screen color-adjustment guides. On older sets, they have to remove the protective casing on the back of the TV to adjust the circuitry with a screwdriver.
Some technicians claim a "golden eye," or the ability to adjust color simply by sight.
Most scoff at such a notion, saying that $7,000 color-analysis instruments give much more precise results.
Some dealers sell a $50 do-it-yourself calibration tool from Imaging Science. It's a laser disk or digital video disk with color test patterns and step-bystep instructions.
Web sites devoted to the fine points of picture quality have begun to proliferate.
Manufacturers point out that when color standards were set, no one expected TVs to be viewed in bright rooms or to have such large screens. They add that certain advances in TV design-including adjustments to the phosphorus lining of the screen-have reduced the damage that ultrabright settings do to picture tubes.
In the past few years, TV makers have begun to bow to the demands of
discriminating viewers by adding sophisticated controls to their fanciest sets. Viewers can even access a menu of color temperatures with their remotes on many sets 27 inches and larger. But not all these models can be adjusted down to the 6,500 Kelvin standard.
Some top-of-the-line TVs use tiny microchips to automatically adjust brightness, hue and contrast for different types of programming. Sony's remote menu, for example, includes special settings for sports, news and movies.
**Zenith Electronics Corp. has a special setting for video games, among other choices.
Although sports settings are generally brighter than those for movies, precise specifications vary depending on the manufacturer. "It's all subjective," says Jim Palumbo, vice president for consumer television products at Sony Electronics Inc.
Confusing terminology adds to the complexity. On many sets, the lowest color temperature setting, usually 6,500 Kelvin, is designated "warm," while the highestmore than 10,000 Kelvin-is called "cool." Toshiba's Mr. Eggers concedes that it's "backwards from what you think." He says viewers associate the brighter picture of a 10,500 Kelvin setting with cool temperatures.
Fine Tuning
Viewers can't adjust 'color temperature' on most TVs. But some
expensive sets let viewers select settings for different programs. A
sampling from Zenith Electronics Corp.:
MODE, MPERATURE, PURPOSE,EFFECT
movie, 6,500 K., cinema-like, contrast reduced Effect brightness increased
sports, 8,000 K., crisp detail, contrast and color increased
daylight, 10,000 K., reduced high contrast,shadows
videogame, 10,000 K., easy sustained lowest contrast,viewing
sharpness reduced
weak signal, 8,000 K., reduced "snow", contrast and color reduced
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