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3D TVs: Frequently asked questions

Our experts answer common questions about 3D TV technology

Last reviewed: January 2011
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How does 3D TV work?
Do I need to wear those red-and-blue 3D glasses?
What else will I need?
Should I buy a 3D TV now?
What is there to watch in 3D at home?
Can everyone see the 3D video effect?

Q: How does 3D TV work?

A: Animated movies such as "Monsters vs. Aliens" are constructed using 3D models, rendering a second view so that each eye gets its own image. With live-action movies featuring humans, special 3D cameras capture two images, representing the different perspectives of the left and right eye. The differences between those two images create a sense of depth. Your brain combines the two images into one seamless 3D image when you wear special glasses, which are capable of presenting each eye with its own separate view. Without the glasses, you'll just see a blurry double image.

For the best 3D effects, you need special 3D content, either from a 3D Blu-ray disc, or from a 3D television broadcast. Most 3D TVs, have powerful processors that can render regular 2D content into 3D on the fly. In our tests, the results didn't look nearly as realistic as true 3D.

Q: Do I need to wear those red-and-blue (or green) 3D glasses?

A: Just like in the movie theater, you need to wear glasses to enjoy the 3D effect with 3D TVs. But these aren't the cheap cardboard shades that used to be given out at theaters, or even the newer Ray-Ban-style polarized ones. Most TVs use active LCD shutter-style models that blink on and off rapidly so that each eye sees its own slightly different image in full 1080p. Your brain then synthesizes them into a single image that shows a sense of depth.

Active 3D glasses are fairly large, so you can put them on over prescription glasses if you wear them. But we've found some glasses to be heavy and awkwardly designed, making them uncomfortable, especially for prolonged viewing.

3D-capable LCD and plasma sets may come with one or two pairs of glasses, but others don't include any unless you also buy a bundle including a 3D Blu-ray player (or a home-theater-in-a-box system that includes that player) and some movies. We've also seen promotions that offer a "3D starter pack"—which typically includes two sets of 3D glasses and a 3D movie—with the purchase of a new 3D TV. You can buy glasses separately, but if you have to buy glasses for several members of your household, or if you lose or break a pair, it can get expensive. The models in our labs cost $130 to $150 each, though less-expensive versions may become available later. Some lower-priced models will use a replaceable battery, while others will use a rechargeable battery that can be charged when plugged into the TV's USB port.

Universal glasses have just hit the market, and we're testing them to see how well they work with various brands. They're lighter, but they aren't much less expensive: about $130 for XpanD's X103 model and $230 for Monster's Vision Max 3D starter kit plus $160 for extra glasses.

Other TVs announced early in 2011 use passive glasses more like those you get in theaters. They don't need batteries, so they're lighter and less expensive than active glasses. There are no shutters, so 3D images might be brighter, with less ghosting. They accept prescription lenses, and some serve as sunglasses. We'll have to see how effective TVs using passive glasses are compared with those using active glasses. 3D TVs that don't require any glasses might be here in a few years, but viewing angle and resolution will be a challenge.

Q: What else will I need?

A: You'll have to buy more than a 3D TV if you want to watch prerecorded 3D movies at home. You'll need a new 3D Blu-ray player too. There are a number of models now on the market, which start at less than $150; some are considerably more expensive.

The Sony PlayStation 3 game console and some DirecTV HD receivers have received firmware updates that enable them to transmit 3D signals to a 3D-capable TV. We expect some cable boxes to follow suit.

Q: Should I buy a 3D TV now?

A: The answer depends on your situation.

YES—If you're an early adopter who's willing to spend more to have the hottest new technology, then do it. These 3D TVs are the real deal, and the effect is eye-popping and just plain fun.

MAYBE—If you're an average consumer planning to buy a new TV anyway, consider it a way of future-proofing your purchase. The TV will cost several hundred dollars more than a traditional set, and it works just like any standard TV. But it will be ready to handle 3D when you decide to get a 3D Blu-ray player, or when DirecTV, ESPN, and perhaps some cable stations decide to offer 3D programming.

NO—If you're happy with your current HDTV, don't need a new set, and aren't burning to have the latest, greatest technology before everyone else. As 3D moves to more mainstream models in a TV manufacturer's lineup, it'll become less expensive, and more 3D content will be available.

Q: What is there to watch in 3D at home?

A: There isn't too much to watch in 3D at this point, but more is on the way. Some early Blu-ray titles were tied to exclusive bundle deals, so they were available only if you bought a 3D TV or Blu-ray player from a certain manufacturer. As deals expire, those movies will be widely available. Also, we expect about 70 new 3D Blu-ray titles to be released this year.

You'll also see more broadcast content as DirecTV expands the offerings on its n3D full-time 3D channel (developed in conjunction with Panasonic), ES PN 3D moves to 24/7 3D broadcasts starting in February, and the new 3Net channel—a partnership between Discovery, Sony and IMAX—debuts this spring. Other TV service providers—including cable operators, Verizon (FiOS), AT&T (U-verse), and the Dish satellite network—will probably expand their 3D program offerings, either by adding 3D networks such as ES PN 3D, or by delivering 3D movies as video-on-demand or pay-per-view selections.

We also expect to see some 3D programs and movies delivered via IP over broadband connections. For example, Vudu recently began offering 3D movies as part of its streaming video service, and we expect others to follow suit.

Finally, most new 3D TVs have a 2D-to-3D conversion feature, which means they can render regular two-dimensional content in 3D on the fly. Although our initial tests of this feature haven't found it to be especially compelling, some viewers may find it an acceptable way of adding more 3D content.

Q: Can everyone see the 3D video effect?

A: Not necessarily. About 5 percent to 10 percent of the population doesn't have true depth perception, and far more may have trouble with their binocular vision, which is needed to see the 3D images in movies or the new 3D TVs on the horizon. People whose eyes aren't perfectly aligned because of strabismus (the eyes don't align when focusing) or amblyopia (the loss by one eye to see details), or who struggle to keep their eyes lined up and moving together, will probably have difficulty fusing the images into a 3D experience. Moreover, the challenge may cause eyestrain (dry, irritated, or painful eyes), which may lead to headache.

For more information, see Having trouble seeing 3D? on the Consumer Reports Health Blog.