Home 3DTV Realities

This article began as a reply to a post on CNET. It has turned into an article that will be added to for more technical content and links.

Minimalist, you've exposed many of the problems of 3DTV, but there are many more. There are also a lot of engineers out there solving them, including new standards. Most of the standards though, are dealing with compression and transmission, so expect a format war that will make the hardware choices difficult...and tend to making the choice of waiting the best one.

As is typical in cases like this, there is more than one technology for glasses. It seems that the more expensive shutter type glasses are becoming the favorite choice, even though they are more expensive. The other type, with the circular filters have the more expensive screen (the filter is difficult to apply and align correctly) but the less expensive glasses. In theory, both cause less light to come to the eye, but the filter technology would cause even less than the shutter type. Not a problem if you can kick up the gain smoothly during 3D watching, and back again for 2D material, but generally not a panacea. 

Because of the way that they work, the filter systems also deliver half the picture at a time, interlacing lines. In theory, this will make fast moving scenes stutter. TVs are now already being built with smoothing technology, the so-called 'Movie' mode to handle the 24 to 30 frame issues, but to some eyes that sucks resolution. 

There are going to be glasses for a long time. The problems of glasses-free designs may be solved eventually, but they are many. The company with the largest investment pulled out after spending a fortune trying to make it work, Phillips Wow technology. It can work, as long as one keeps ones head stationary, and level. Making it work for more people means less light to everyone's eyes, which is fine for a while, but still, no one can look at anyone to see how cool they look without glasses, without breaking up the 3D image. ...among other problems. Screens with 4K resolution (4 times what we have now) can solve some of this, but not all. The Digital Signage field will still be developing this technology for their purposes, but don't confuse their advances (or press releases) for Home3DTV advances.

Generally, the main ingredient for 3DTV is a fast TV, and most new TVs are above the refresh rate to handle 3D. Since 50Hz in much of the world, and 60Hz in the States can support good HD, and since half the signal has to be blocked half the time, one needs twice those speeds to make 3D work. Of course, if the technology can match it, even faster is better. Cinema screens get flashed 6 times per 1/24th of a second (3 times for each eye) when showing 3D movies. That explains what Sony is aiming for with 200Hz technology.

That makes other considerations important, like transmission and set-top boxes and what happens when 2D gets mixed with 3D. Sequential, being theoretically 2 full HD fields, needs more data to make a HiDef 3D picture, more than can fit into the HDMI 1.3 pipe. 1.4 is being presented in the market, so that is good, but there is a codec to match that, making everything easier in the future, H.264 MVC. That codec, among other technology, needs to get into the set-top box or into the TV.

Ultimately, home 3DTV is a fast moving field. It is probably not a fad. It is properly called Stereoscopy, since it isn't a real 3D hologram. But stereoscopy is one of the major clues we get in nature, so when it is done right on a screen, it can be very natural, pleasing and additive to the experience. It is probably not going to be as big switch as the switch to HD, but a lot of people are betting big amounts that it will succeed. 

We'll continue to add onto this article, with more technical and current data, as well as links. Eventually, it will be an FAQ. Any help will be appreciated.