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

That is, provided you can afford it. 3D video at its most sophisticated requires hardware that many people don't already have: 3D-capable TVs and the electronic glasses used with them.

3D capacity on a new high-end TV may not add that much to the base price - figure on at least £1,500 for a 46in TV - but the glasses alone can run as much as £100 per pair.

Add it up for a family of four, and you're probably spending nearly £2,000.

Getting 3D capabilities on a PC is also expensive. For example, a pair of Nvidia's 3D Vision glasses are £150, but that's only part of the cost. You also need a display that can handle 3D, which generally costs around £200 to £300 for a 22in or 23in 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 polarised 3D seen in movie theatres, which would allow the use of glasses that cost only a few dollars - but the sets themselves could cost anywhere from £300 upwards.

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

NEXT PAGE: The history of 3D

  1. Introduction
  2. The history of 3D
  3. A new technology emerges
  4. 3D: Who needs it?
  5. Gaming
  6. Conclusions

This year vendors are pushing expensive 3D displays, but the technology may not be as ready as they claim. We look at what's available and who needs it.

The history of 3D

3D 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 3D - 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 3D system introduced in the last decade, are able to reproduce a fairly large spectrum of colours.

Because anaglyph 3D 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' 3D effects. Even Nvidia's 3D-enabled display hardware supports anaglyph 3D as a lowest-common-denominator way to show 3D on any display.

There are two big problems with anaglyph 3D, 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 colour is always lost, even if you use a system that restores colour.

When 3D hit the movies in the 1950s - its first appearance was in Arch Oboler's Bwana Devil - it used polarised 3D, one of the most common systems still in use today for movies. The images for each eye were projected through a polarisation filter, and the viewer wore polarised glasses to reconstruct the 3D image. This system preserved colour information and didn't lose as much image detail as anaglyph 3D.

But it required a type of screen that preserved polarisation 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.

NEXT PAGE: A new technology emerges

  1. Introduction
  2. The history of 3D
  3. A new technology emerges
  4. 3D: Who needs it?
  5. Gaming
  6. Conclusions

This year vendors are pushing expensive 3D displays, but the technology may not be as ready as they claim. We look at what's available and who needs it.

A new technology emerges

It took the invention of the liquid crystal display (LCD), among other things, to bring us active-shutter 3D technology, which is the current state of the art and the basis for most 3D 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 120Hz. 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-colour images can be used.

But there are downsides. For one, between the darkened glasses and the 120Hz image-switching, the image has its brightness effectively cut in half. This isn't bad if you're already in a darkened room (eg a home theatre) but can be problematic if you're not. Second, you have to actually wear 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 3D glasses. So, for example, if you give a party for your kids and want to show a 3D 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 £100 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 3D, and right now there's just not very much 3D video material out there, either live-broadcast or pre-recorded.

Many of the barriers in generating 3D content are both technical and economic. Much as the early years of colour created technical challenges for film and TV crews, filming in 3D 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 3D content warrants it.

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

It's also possible to have consumer equipment perform re-synthesise 2D to 3D on the fly. Cyberlink's current version of its PowerDVD application comes with a feature called TrueTheatre 3D, which allows 3D video to be derived from a conventional 2D DVD. Toshiba's series of Cell TVs also promises to convert 2D to 3D 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 analysing a 2D image (or even a 2D motion stream). This was one of the problems faced by movie studios when they wanted to convert recent movies such as Titans and Alice in Wonderland from 2D to 3D. By the experts' own admission, some degree of manual work is required for the technique to really work, which means automatic conversion of 2D to 3D by software or hardware is going to yield limited results at best.

NEXT PAGE: 3D: Who needs it?

  1. Introduction
  2. The history of 3D
  3. A new technology emerges
  4. 3D: Who needs it?
  5. Gaming
  6. Conclusions

This year vendors are pushing expensive 3D displays, but the technology may not be as ready as they claim. We look at what's available and who needs it.

3D: Who needs it?

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

The size and detail of most scenes in a movie, especially on a big screen, create a 3D effect all their own. Add actual 3D 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 3D documentary about the Chauvet cave paintings?

Questions like these, plus the technical problems generated by 3D, prompted movie critic Roger Ebert to pen an essay for Newsweek where he decried theatrical 3D 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 theatre owners into buying the next generation of projection hardware.

Critic A.O. Scott of The New York Times stated that 3D seemed better suited to animation than to live-action, and that the "pop-out holographic effects feel more tacked-on" for "earthbound" 3D films like Alice in Wonderland and Clash of the Titans.

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

Another possible problem with 3D is medical, not aesthetic. An associate professor of ophthalmology was quoted on CNN.com as saying that about 20 percent of viewers who watch 3D 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 2D and try to show it in 3D: viewers can't focus or track that's going on in front of them fast enough, and they become ill.

3D 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 3D glasses may not be noticeable to most people, but those sensitive to it can have everything from headaches to seizures. 3D TV manufacturer Samsung has issued warnings about this.

NEXT PAGE: Gaming

  1. We look at why the technology may not be as advanced as manufacturers claim
  2. The history of 3D
  3. A new technology emerges
  4. 3D: Who needs it?
  5. Gaming
  6. Conclusions

This year vendors are pushing expensive 3D displays, but the technology may not be as ready as they claim. We look at what's available and who needs it.

Gaming

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

There are several reasons 3D 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 3D games and displays with only a firmware upgrade, and games are the kind of experience where 3D adds something truly useful.

Previous stabs at 3D 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 3D 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 3D, 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 3D system on a Samsung 120-Hz plasma TV. The 3D effect was satisfying, if a little dim, and any flickering from the shutters on the glasses was imperceptible.

3D without glasses

One way 3D could make major inroads against 2D 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 3D system), but a number of companies are working on 3D displays that use existing technologies in creative ways.

Most people reading this have seen a form of 3D called lenticular 3D, which uses a sheet of plastic lined with vertical grooves as a kind of lens to create a 3D 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 3D sans glasses. Video game titan Nintendo's forthcoming handheld 3DS console is said to sport not only a 3D display but possibly two cameras as well for player motion-tracking.

NEXT PAGE: Conclusions

  1. Introduction
  2. The history of 3D
  3. A new technology emerges
  4. 3D: Who needs it?
  5. Gaming
  6. Conclusions

This year vendors are pushing expensive 3D displays, but the technology may not be as ready as they claim. We look at what's available and who needs it.

Conclusions

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

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

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

See also: Revealed: the truth about the future of 3D TV

  1. Introduction
  2. The history of 3D
  3. A new technology emerges
  4. 3D: Who needs it?
  5. Gaming
  6. Conclusions