The Facts About 3-D TV: Is It Really Ready?

After decades of being a gimmick confined to midnight movies, 3-D has finally hit the big time, with a slew of 3-D-enhanced films streaming out of Hollywood. And it's not just an IMAX theater spectacle; it's coming to living rooms and computer displays near you.

Donning glasses to see 3-D effects on a big-screen plasma display.
That is, provided you can afford it. 3-D video at its most sophisticated requires hardware that many people don't already have: 3-D-capable TVs and the electronic glasses used with them. 3-D capacity on a new high-end TV may not add that much to the base price -- figure on at least $2,500 for a 46-in. set -- but the glasses alone can run as much as $150 to $200 per pair.

Add it up for a family of four, and you're probably spending over $3,000.

Getting 3-D capabilities on a PC is also expensive. For example, a pair of Nvidia's 3-D Vision glasses are $200, but that's only part of the cost. You also need a display that can handle 3-D, which generally costs around $300 to $500 for a 22-in. or 23-in. display, and your PC must have a compatible Nvidia graphics card and be running Windows 7 or Vista.

LG and other companies are planning TVs that use the type of polarized 3-D seen in movie theaters, which would allow the use of glasses that cost only a few dollars -- but the sets themselves could run $500 to $1,000 more.

So although 3-D in the home has indeed become viable, it needs to be made into more than just a gimmick to justify its premium cost.

The History of 3-D

3-D imagery, or stereoscopy, has been around in various forms for a long time. The basic idea remains simple: Use two cameras to take the same picture from slightly different angles, as a way of reproducing how the human eye sees things. Fisher-Price's View-Master toy, which many of us had as children or have given to our own children, is a good example of a basic stereoscope.

Another early system was anaglyph 3-D -- the system that uses the iconic red and blue glasses. That process, patented in 1891 by French scientist Louis Ducos Du Hauron (but a refinement of a technique used since the 1840s), allowed only black-and-white images at first, but newer anaglyph systems, such as the ColorCode 3-D system introduced in the last decade, are able to reproduce a fairly large spectrum of colors.

Because anaglyph 3-D works in just about any format (TV, movies, print) and is relatively cheap to implement, it's still widely used today for "quick and dirty" 3-D effects. Even Nvidia's 3-D-enabled display hardware supports anaglyph 3-D as a lowest-common-denominator way to show 3-D on any display.

There are two big problems with anaglyph 3-D, however. One is a general fuzziness to the image, since details tend to get lost in the red channel. The second is the way a certain amount of color is always lost, even if you use a system that restores color.

An anaglyph 3-D image using the anachrome system to restore some of the original colors.
When 3-D hit the movies in the 1950s -- its first appearance was in Arch Oboler's Bwana Devil -- it usedpolarized 3-D, one of the most common systems still in use today for movies. The images for each eye were projected through a polarization filter, and the viewer wore polarized glasses to reconstruct the 3-D image. This system preserved color information and didn't lose as much image detail as anaglyph 3-D.

But it required a type of screen that preserved polarization of light, a phenomenon where light waves are filtered so that only those vibrating in a certain direction are allowed. This limitation made the system best suited to theatrical projection rather than TV. Also, many objects on screen still sported odd halos or blurry edges, which could make it uncomfortable to watch for prolonged periods of time.

A new technology emerges

It took the invention of the liquid crystal display, among other things, to bring usactive-shutter 3-D technology, which is the current state of the art and the basis for most 3-D displays on the market today.

Viewers don glasses with lenses that are actually LCD shutters that can alternate between blocking the left and right eye 120 times per second -- in other words, they alternate at 120 Hz. They then look at a screen that syncs with the glasses to show the appropriate image for each eye. The images don't have blurry fringes or "ghosts" as they do in other systems, and either black-and-white or full-color images can be used.

The Asus G51J 3D laptop uses active-shutter 3-D technology.
But there are downsides. For one, between the darkened glasses and the 120-Hz image-switching, the image has its brightness effectively cut in half. This isn't bad if you're already in a darkened room (e.g., a home theater) but can be problematic if you're not. Second, you have to actuallywear the glasses, and that by itself is a distraction -- doubly so for people who already have visual problems or simply find glasses annoying.

And finally, there is not yet a standard for 3-D glasses. So, for example, if you give a party for your kids and want to show a 3-D cartoon on your Sony TV, your kids' friends may not be able to watch the cartoon using the glasses from their Samsung TV. And at $200 a pop, it's unlikely you'll want to buy glasses for the whole crew.

The content crunch

What matters more than the tech, though, is content. Content is king, especially when it comes to 3-D, and right now there's just not very much 3-D video material out there, either live-broadcast or prerecorded.

Many of the barriers in generating 3-D content are both technical and economic. Much as the early years of color created technical challenges for film and TV crews, filming in 3-D requires special cameras and the technical expertise to use them. It's not insurmountable -- people can be brought in and trained on new equipment in fairly short order -- but only makes sense if the demand for 3-D content warrants it.

Of course, there's the possibility of converting existing 2-D material to 3-D. For example, although the recent remake of Clash of the Titans was not shot in 3-D, it did have a 3-D theatrical release.

It's also possible to have consumer equipment perform resynthesize 2-D to 3-D on the fly. Cyberlink's current version of its PowerDVD application comes with a feature called TrueTheater 3D, which allows 3-D video to be derived from a conventional 2-D DVD. Toshiba's series of Cell TVs also promises to convert 2-D to 3-D on the fly but won't be released until later this year.

The problem with either approach is that it requires adding picture information that was never there to begin with, and which can't always be deduced by analyzing a 2-D image (or even a 2-D motion stream). This was one of the problems faced by movie studios when they wanted to convert recent moviessuch as Titans and Alice in Wonderland from 2-D to 3-D. By the experts' own admission, some degree of manual work is required for the technique to really work, which means automatic conversion of 2-D to 3-D by software or hardware is going to yield limited results at best.

3-D: Who needs it?

That brings us to another issue with 3-D entertainment, one that doesn't get as much discussion in technical circles: the aesthetic and artistic problems that 3-D introduces.

The size and detail of most scenes in a movie, especially on a big screen, create a 3-D effect all their own. Add actual 3-D to that, and you have to make a bevy of additional decisions. How often can you cut without disorienting the audience? What do you keep in focus? One thing? Everything? Do you try to make things pop out of the screen or instead sink into it, as director Werner Herzog plans to do with his upcoming 3-D documentary about the Chauvet cave paintings?

Questions like these, plus the technical problems generated by 3-D, prompted movie critic Roger Ebert to pen an essay for Newsweek where he decried theatrical 3-D as a gimmick. It is a way not just to scalp ticket-buyers out of an extra $5 a head, he declared, but also a way to pressure theater owners into buying the next generation of projection hardware. Critic A.O. Scott of The New York Times stated that 3-D seemed better suited to animation than to live-action, and that the "pop-out holographic effects feel more tacked-on" for "earthbound" 3-D films like Alice in Wonderland and Clash of the Titans.

In other words, a good 2-D movie doesn't need 3-D to make it even better, just as a good black-and-white movie isn't crippled by not having color.

Another possible problem with 3-D is medical, not aesthetic. An associate professor of ophthalmology was quoted on CNN.com as saying that about 20% of viewers who watch 3-D content for prolonged periods of time experience vertigo and nausea.

It's possible to blame some of that on what happens when you take fast-moving content better suited for 2-D and try to show it in 3-D: Viewers can't focus or track what's going on in front of them fast enough, and they become ill. 3-D also seems to be that much more problematic for people who have vision problems like strabismus or who are photosensitive epileptics. The strobing effects created by 3-D glasses may not be noticeable to most people, but those sensitive to it can have everything from headaches to seizures. 3-D TV manufacturer Samsung has issued warnings about this.

Gaming

3-D movies and TV may be an iffy bet, but there's another kind of entertainment that may not only generate more enthusiasm for 3-D but be truly suited to it: video games.

There are several reasons 3-D and gaming are a good fit. The gaming audience is generally receptive to new technology (and typically has the disposable income for it), current-generation consoles and systems can generally support 3-D games and displays with only a firmware upgrade, and games are the kind of experience where 3-D adds something truly useful.

Previous stabs at 3-D gaming, such as 1995's Nintendo Virtual Boy, were clunky because they depended on technology that didn't work anywhere else. The newest gaming systems use the same 3-D system as the TV itself and can piggyback on that technology, just as they did with HD.

As with movies, not every game benefits from being 3-D, but those that do benefit quite a lot. Late last year, at Microsoft's Windows 7 launch in New York, I tried out the PC edition of Batman: Arkham Asylum using an active-shutter 3-D system on a Samsung 120-Hz plasma TV. The 3-D effect was satisfying, if a little dim, and any flickering from the shutters on the glasses was imperceptible.

3-D without glasses

One way 3-D could make major inroads against 2-D is via a display technology that doesn't require glasses. Science fiction has entertained concepts like this for decades -- a holographic image projected into the air, or displayed inside a cube or sphere. Such systems are still a long way off (although a company named SeeReal is working on a holographic 3-D system), but a number of companies are working on 3-D displays that use existing technologies in creative ways.

Most people reading this have seen a form of 3-D called lenticular 3-D, which uses a sheet of plastic lined with vertical grooves as a kind of lens to create a 3-D effect in postcards and public ads. A few companies are working on displays that use variations of this technology. An outfit called CubicVue sells a lenticular filter that is designed to fit over an existing display; the company also says its technology can be embedded in displays, which I imagine would give better results.

Display manufacturers aren't the only ones interested in 3-D sans glasses. Video game titan Nintendo's forthcoming handheld 3DS console is said to sport not only a 3-D display but possibly two cameras as well for player motion-tracking.

Conclusions

There will always be people who are driven to acquire the newest bleeding-edge technology, and those folks have probably already bought a 3-D TV. For the rest of us, it makes sense to wait until some of the kinks have been worked out of home 3-D display technology.

The truth is that 3-D isn't going to replace 2-D -- because there are plenty of reasons to keep 2-D. It's practical, effective and above all cheap. Almost every 3-D technology in existence today comes at a cost premium. Even when the costs fall, it will still be tougher to create 3-D content -- especially original 3-D and not something merely resynthesized from 2-D.

What 3-D has done and will continue to do is create a small but significant market for specialty content. It won't eclipse 2-D but rather will complement it -- the way netbooks and the iPad are flanking and accompanying conventional desktops and notebooks. And the move toward 3-D that doesn't require anything but our own two eyes to see it means the adventure into a new dimension has barely begun.

Serdar Yegulalp has been writing about computers and information technology for over 15 years for a variety of publications, includingInformationWeek and Windows Magazine.

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