How 3-D TV works

This week's experiments in 21st-century 3-D television viewing are just the start for a technology that some filmmakers hope will soon be right up there with HD and Blu-Ray on the coolness scale.

Sunday's Super Bowl commercials provided a little taste of the current state of 3-D for the small screen - and the reviews were mixed: Based on rewind ratings, Tivo said the ads for the DreamWorks animated film "Monsters vs. Aliens" and for Sobe bottled water "fell well short of the pace, barely cracking the top 50."

MTV's Larry Carroll said the 3-D movie preview  "looked fun," while The New York Times' Stuart Elliott said "it's not going surpass my memories of the one time I watched Hitchcock's 'Dial M for Murder' in 3-D."

The acid test could come tonight, when NBC airs an hour-long 3-D episode of its geek-spy show, "Chuck." (NBC Universal is a partner in the msnbc.com joint venture.) The video is encoded to produce a 3-D effect when you see it through the same amber-blue ColorCode glasses that were distributed at retail outlets in advance of the Super Bowl. Will viewers wear those paper glasses for an hour? If not, will the show still look OK without the glasses? Stay tuned ...

In any case, when 3-D TV is actually ready for prime time, you won't be using the funny paper glasses with colored lenses, said Jim Mainard, the head of production development for DreamWorks Animation. Instead, you'll be using the funny plastic glasses with polarized lenses.

Mainard is one of the main guys responsible for moving DreamWorks' animation studio to an all-3-D operation. Eventually, all that 3-D content - like "Monsters vs. Aliens" - will be moving from the big screen to the small screen. As we saw at last month's Consumer Electronics Show, some HD television sets are already built to display 3-D shows the way they should be seen, and Mainard says many more "3-D Ready" sets will be hitting the market.

"I think it'll be a standard thing on television sets in the next few years," he told me.

The Super Bowl commercials and the "Chuck" episode are still in the gimmick category, but some of the systems being tested and sold come much closer to the 3-D theater experience. Rather than transmitting a single color-coded signal, these TV sets display two sets of signals, one for the left eye and one for the right eye. The difference lies in the way your eyes are fooled into seeing the two views separately:

• Lenticular viewing: These 3-D sets are meant to be watched without any funny glasses. Instead, the monitor incorporates a special lens that sends different signals to each eye, as long as you're sitting in a "sweet spot." The 3-D effect is similar to that produced by those novelty postcards with a grooved plastic layer on top. The technology, pioneered by Philips, is available today - but Mainard thinks the sweet-spot requirement might be too limiting for home viewing.
• Active glass systems:Samsung and Mitsubishi are offering "3-D Ready" sets that rely on LCD glasses that alternate their polarization between the left and the right eye, in time with the refresh rate on the TV monitor. In effect, you see one frame with the left eye, the next with the right - repeated, say, 60 times a second. (Mitsubishi is also working on a specialized kind of no-glasses 3-D display using lenticular technology.)
• Passive glass systems:Hyundai, JVC and other companies are working on TV sets that can switch between the usual 2-D display and a 3-D display meant to be seen with plain old polarized glasses - the kind of glasses that come by the binful at theme-park 3-D theaters. In 3-D mode, every other line carries a clockwise or a counterclockwise polarization. Thus, each eye gets half of the visual information on the screen, but your brain puts it together to create one picture with the 3-D effect. This Web page explains the active vs. passive distinction.

Mainard said the passive-polarized systems are "quite amazing" and add only $100 to $200 to the cost of a TV set. However, he said, DreamWorks' 3-D content can be converted to any display standard, for the theater or for home viewing. The important thing is to arrive at a standard.

"Our final frames are ready to go, independent of whether they go to RealD or Dolby ... or ColorCode," he said. After all, transforming a computer animation from 2-D to 3-D is just a question of software (and processing power), as we discussed more than four years ago.

The important thing is to settle on a standard for television sets and DVDs. If the standards, the hardware and the content come together, 3-D could become as much of an attraction as HD is today - and boost the sales of next-generation players in the process.

"In many ways, it could be the savior of Blu-Ray," Mainard said.

What do you think? Will 3-D TV always remain a gimmick, or could it become the new frontier of home entertainment? Feel free to weigh in with your comments below - and don't throw away those funny glasses!