3D TV FAQ

The recent flood of news about new 3D TVs, itself spurred by the hype surrounding the 3D release of Avatar, has raised a few questions. At CNET, one of our main jobs is to explain "new" technology, so this article, arranged in the tried-but-true manner of "Frequently Asked Questions," attempts to answer them as well as we can at this early stage.

We polled the six major TV makers who announced new 3D models--LG, Panasonic, Samsung, Sony, Toshiba, and Vizio--to help with some answers. Although many of the questions elicited variations of "we'll get back to you on that," responses to the others, combined with judicious trolling of Web resources (special thanks to AVS forum and the friendly folks at EngadgetHD), allowed us to cobble together the following. It will be updated and expanded as--inevitably--parts are proven wrong or we're actually given some hard information. In the meantime feel free to leave a comment, or at least vote in the poll

1. What is 3D TV?

3D TV is a generic term for a display technology that lets home viewers experience TV programs, movies, games, and other video content in a stereoscopic effect. It adds the illusion of a third dimension, depth, to current TV and HDTV display technology, which is typically limited to only height and width ("2D").

2. How can you get 3D from a 2D screen?

A 3D TV or theater screen showing 3D content displays two separate images of the same scene simultaneously, one intended for the viewer's right eye and one for the left eye. The two full-size images occupy the entire screen and appear intermixed with one another--objects in one image are often repeated or skewed slightly to the left (or right) of corresponding objects in the other--when viewed without the aid of special 3D glasses. When viewers don the glasses, they can perceive these two images as a single 3D image.

The system relies on a visual process called stereopsis. The eyes of an adult human lie about 2.5 inches apart, which lets each eye see objects from slightly different angles. The two images on a 3D TV screen present objects from two slightly different angles as well, and when those images combine in the viewer's mind with the aid of the glasses, the illusion of depth is created.

Most people are familiar with the old anaglyph method, where a pair of glasses with lenses tinted red and cyan (or other colors) is used to combine two false-color images. The result seen by the viewer is discolored and usually lower-resolution than the new method.

The principal improvements afforded by new 3D TV technologies are full color and high resolution--reportedly full 1080p HD resolution for both eyes in the Blu-ray 3D system, for example, and lower resolution in the DirecTV system. We expect DirecTV's 3D channels to look quite sharp despite lack of full 1080p resolution; see HDTV resolution explained for some reasons why.

New 3D TVs require active liquid crystal shutter glasses, which work by very quickly blocking the left and then the right eye in sequence (120 times per second systems like Panasonic's Full HD 3D). The glasses, in addition to the liquid-crystal lenses, contain electronics and rechargeable batteries (typically good for 80 or more hours), that sync to the TV via an infrared or Bluetooth signal.

(Note: For the remainder of this article, any mention of "3D" refers to the new full-color, high-resolution version, not the old anaglyph variety.)

Many viewers have also experienced newer 3D presentations, such as IMAX 3D, in movie theaters. Though the technologies differ somewhat--most theaters use passive polarized 3D glasses, for example--the main practical difference between 3D TV in the home and theatrical 3D is the size of the screen. In the home, the image is generally much smaller, occupying a lower percentage of viewers' fields of vision. Among TV makers we asked, only Panasonic recommend a closer seating distance (of 3x the screen height away--about 6.2 feet from a 50-inch screen) for a better experience; however, we suspect sitting closer or watching on a bigger screen will definitely help with any home 3D presentation. Smaller screens also can present other issues unique to 3D, such as a relatively narrow viewing distance range.

5. Can everyone see 3D?

No. Between 5 percent and 10 percent of Americans suffer from stereo blindness, according to the College of Optometrists in Vision Development. They often have good depth perception--which relies on more than just stereopsis--but cannot perceive the depth dimension of 3D video presentations. Some stereo blind viewers can watch 3D material with no problem as long as they wear glasses; it simply appears as 2D to them. Others may experience headaches, eye fatigue or other problems. (Related: See Rafe Needleman's TV industry turns blind eye to non-3D viewers' article.)

6. I've heard 3D causes headaches. Is that true?

Most viewers of 3D suffer no ill effects after a brief orientation period (lasting a few seconds as the image "snaps" into place), but in others, 3D can cause disorientation or headaches after extended periods. Viewer comfort is a major concern of 3D content producers; too much of a 3D effect can become tiresome after a while, abrupt camera movement can be disorienting, and certain on-screen objects can appear blurry, for example. Creators of 3D movies for children also have to account for the fact that a child's eyes are closer together (about 2 inches) than an adult's.

7. Does everyone watching a 3D TV need to wear the glasses?

Yes. Every member of a family sitting around the 3D TV must wear the glasses to see the 3D effect. If they don't, the image on the screen will appear doubled, distorted, and, for most practical purposes, unwatchable. Currently, there's no technology that lets a single TV display both 2D and 3D content simultaneously without glasses.

People who wear normal prescription lenses already can experience the full effect--and generally suffer little or no discomfort--by wearing the 3D glasses too, which are designed to fit over an existing pair of glasses.

8. Do I need a new TV?

Yes. None of the TV manufacturers we spoke with said that its current HDTVs can be upgraded to support the new 3D formats. We've heard that slow LCD response times, processing power, new phosphor requirements, and an inability to accept the necessary 120Hz input signal (not to be confused with 120Hz and higher display refresh rates) cited as reasons why existing sets are stuck in 2D. We're not ruling out such future upgrades, perhaps by third-party add-ons, but as of now, it's basically impossible as far as we know.

The one exception applies to the 3D compatible DLP and plasma TVs released in the last couple of years. Mitsubishi will release an adapter box this year that lets its 3D DLP TVs work with new 3D sources, including Blu-ray players. The resulting picture quality after the upgrade is an open question, and Mitsubishi hasn't said whether its box will work with 3D-compatible DLP TVs from other makers. Samsung, which made 3D compatible DLP TVs through 2008, said it has no plans to release a similar adapter nor make its "3D-ready" plasma TVs, namely the PNB450 (2009) and the PNA450 (2008), compatible with new 3D formats, like 3D Blu-ray.

9. Do I need a new Blu-ray player, cable box, game console, or AV receiver?

With one notable exception--the Sony PS3--the answer for Blu-ray players is "yes." No Blu-ray player maker has said it will upgrade existing standalone players to work with Blu-ray 3D movies, so a new 3D Blu-ray player will be required for many viewers to view the new 3D Blu-rays.

Sony told CNET at CES that the PS3 will support 3D Blu-ray playback with full 1080p resolution to each eye via a simple software update, available later this year. On the other hand, other manufacturers, including Panasonic, have told us HDMI 1.4 is required for full HD 3D, and as far as we know the PS3 does not have HDMI 1.4. As a result, we're skeptical of Sony's "full resolution" claim, although we are fairly certain the PS3 will support 3D, both Blu-ray (at some resolution) and for gaming, at some point this year. We'll update this article when we know for certain.

As for the Xbox 360 and the Wii, neither Microsoft nor Nintendo has outlined its plans for 3D gaming.

DirecTV has said that its lower-resolution 3D system will require only a free software update to the company's current HD boxes. No other TV provider has announced 3D yet, but we assume some will follow suit and enable 3D without a new box.

Unless you use your AV receiver for switching between HDMI video sources, you won't have to upgrade to enjoy 3D Blu-ray movies. You can instead opt for a Blu-ray player with dual-HDMI outputs, such as the Panasonic DMP-BDT350, or forgo high-resolution audio (Dolby True HD or DTS Master Audio) that requires an HDMI connection to the receiver. If you do want to retain HDMI switching on a receiver with even a single 3D source (with the possible exception of the PS3), it appears that you will need to get an AV receiver that's HDMI 1.4-compatible. We expect them to start appearing on the market later in 2010.

10. Can I use my existing HDMI cables?

Probably not for "Full HD 3D." Most TV makers we spoke with specified that to get full 1080p resolution in both eyes, all of the involved devices (player/source and TV, typically) need HDMI 1.4 connections. 3D TVs and players have HDMI 1.4, and we expect most cable suppliers (including the low-priced online merchants that CNET favors) will offer compatible cables soon. We'll also be sure to test for certain, when said equipment becomes available, whether you can use old cables and still get the full HD 3D experience.

DirecTVs's 3D system does not require HDMI 1.4, so you can use your existing cables and AV receiver for that.

11. Can I watch current 2D shows, movies, games, and other content in 3D?

At CES 2010, Samsung and Toshiba representatives both said their sets would include 2D to 3D conversion processing that will allow viewers to "watch everything in 3D." However, we don't expect these systems, especially in their first generation, to come close to the realism of true 3D content. We checked out a canned demo of Toshiba's process at CES and it seemed to work, but it certainly could stand improvement.

Update 01/19/2009: Sony says its 3D TVs will also include a "Simulated 3D Mode" similar to the processing announced by Samsung and Toshiba.

No other TV manufacturer (namely LG, Vizio or Panasonic among current purveyors of 3D TVs) has announced a built-in conversion system. Given the lack of true 3D content, we wouldn't be surprised to hear about a third-party add-on solution soon, similar to Nvidia's 3D Vision kit, that works with the new TVs.

12. Can the 3D feature on a 3D TV be tuned off?

Yes. All 3D TV makers we spoke to said that their sets would display current 2D content with no problem, and we don't expect their picture quality in 2D to be any worse than on an equivalent 2D HDTV. The Blu-ray 3D specification calls for all such discs to also include a 2D version of the movie, allowing current 2D players to play them with no problem. We're not sure whether DirecTV's 3D channels will be viewable in 2D, but it's not likely to be an issue since we expect most of that content to be available on 2D channels.

13. Do 3D TVs use more power?

No manufacturer we asked would say one way or another, although two other sources CNET spoke with (the head of USC's Entertainment Technology Center, as well as Bruce Berkoff of the LCD TV association) said they do not. On the other hand, it's true that the active LC shutter glasses effectively block half of the light arriving from the screen, and the lenses are not entirely transparent to begin with, so logically a TV displaying a 3D image could use more power than the same TV to produce a 2D image of equivalent brightness. But it's just too early to know until we can test one.

14. What 3D TVs are going to be available this year?

Panasonic, Sony, Samsung, LG, Vizio, and Toshiba, among others, announced 3D TVs that will ship in 2010. See CNET's CES 2010 TV wrap-up for more information, or check out the videos.

15. Do 3D TVs come with glasses? How many pairs?

Among TV makers we polled, only Sony, Panasonic, and Toshiba went on record saying that their models, the LX900 series (two pairs), the VT25 series (one pair), and CELL TV (number of pairs not specified), respectively, would include the necessary glasses. We expect most other TV makers will follow suit and include glasses, at least with their flagship 3D models.

16. What 3D movies are coming out this year on home video? 3D TV channels? 3D games?

Blu-ray movies announced this year in 3D include "Cloudy with a Chance of Meatballs," "Monsters vs. Aliens," and "Disney's A Christmas Carol." More movies are sure to be announced. Existing Blu-ray and DVD discs in 3D, such as "Coraline" and "Journey to the Center of the Earth," contain versions of the films in the old anaglyph style, and so cannot deliver full-color, high-resolution 3D.

DirecTV will be the first TV provider with 3D content, announcing three 3D channels of its own. ESPN and Discovery each said it would also launch 3D channels this year, although no provider, including DirecTV, has yet announced carriage of either one.

PCs have been able to deliver 3D games, many converted from 2D versions, for the last few years to some compatible TVs. However, no console games specifically designed to work with the new 3D TVs have been announced, aside from Avatar: The Game. We anticipate 3D versions of existing games to be announced this year, perhaps with an "upgrade path" allowing existing owners to not have to repurchase the game at full price, but nothing's been officially announced yet.

17. Will 3D TVs work with all 3D formats?

Unlike with Blu-ray versus HD DVD, there doesn't seem to be a major "format war" between the various methods for delivering 3D. All of the TV makers we spoke with specified that their upcoming 3D sets would work with the Blu-ray format, and we expect them all to support DirecTV's 3D channels and the well-established RealD format as well. When we asked about other 3D formats, including ones that use side-by-side, checkerboard, and top-and-bottom modes, and 3D found on current source devices like PCs using Nvidia's 3D Vision, TV makers who responded either specified their sets would be compatible or implied they would be by launch time. In short, compatibility shouldn't be a major hurdle for 3D TVs.

18. How much does all of this cost?

We don't know for sure, but the first 3D TVs won't be as expensive as the first HDTVs were, for example. With the exception of Vizio, no HDTV maker has yet announced pricing on its 3D-compatible HDTVs. Though all TV makers are placing 3D only in their more-expensive models this year, we don't expect 3D TVs to cost much more than existing high-end plasmas and LCDs. The same goes for Blu-ray players (there's no word yet on how much, if anything, the PS3's promised 3D upgrade will cost) and for content itself (it's anyone's guess whether 3D Blu-rays will cost a couple bucks more than normal versions).

Again, no TV maker has specified costs for its 3D glasses, although Toshiba came closest when it told us "Glasses may cost $99.99, but this is not yet final," and LG also estimated a price of about $100. Compatibility between glasses and TVs will be left up to individual manufacturers, although we do anticipate the third-party 3D glasses market taking off in the next couple of years.

19. Seriously, is 3D TV any good or just the latest gimmick to get me to buy new crap?

In our early opinion, informed by the limited demos we've seen, the new 3D TV technology seen under the right conditions can be very impressive and definitely delivers a "wow" factor that will appeal to fans of immersive home theater, gamers, and other early adopters. Aside from screen size, the experience is very similar to what you'll see at the theater.

But that screen size difference is huge, and final versions of 3D TVs shipping later this year might perform differently from demos. And we have no idea how home viewing conditions like ambient light, seating distance, viewing angle, and other factors, which figure less prominently into the theater experience, affect 3D in the home.

Finally, when evaluating whether 3D TV is "any good," it's worth drawing attention again to the many issues described above and elsewhere.

And of course, like any new technology (or product for that matter), 3D is in essence intended to get you to buy more stuff. Years of underwhelming 3D implementations and misguided marketing earns 3D more of a right than other technologies to bear the description "gimmick." Again, we recommend seeing 3D in the theater, under ideal conditions, then considering the differences between that and 3D TV in the home, before writing 3D off or becoming a fanboy/girl.

20. I'm thinking of buying a new TV. Should I wait for 3D TVs?

Not unless you're an early adopter or a die-hard 3D fan who simply can't wait for the next best thing. 3D content will be rare in the first couple of years. Glasses, 3D gear, and of course, the TVs themselves will command a premium price. And like any technology, we expect it to improve quickly--although glasses-free 3D is still a few years away. Getting a new, non-3D TV now is still a fairly safe bet, and you can be sure to enjoy it even after 3D becomes more common. Even when 3D is available on just about every TV--something we expect to happen within the next few years--viewers will probably don the glasses mainly for special events like sports and movies, and not necessarily to watch the evening news.

So there you have it: the basics of what we know about 3D TV today. We're still receiving more information from manufacturers, so we'll update this article when it becomes out-of-date, and add new questions and answers when appropriate. In the meantime, feel free to sound off in the comments section if we missed something major, think we did a good job, or you just feel like venting.