Sunday, May 16, 2010

Notes on Stereoscopic 3D

I been following this technology closely for more than a year now and I was convinced that this technology is going to be a game changer when I first heard that Avatar is going to be on 3D. A lot has been happening since Avatar came out and I think one of the crucial outcome was incursion of stereoscopic 3D into main stream broadcast media.

Singapore, as a highly techno friendly country, will be the first among the nations to do a nationwide 3D trial on the broadcast possibly on coming August. I think as for the HD wave it would be interesting to see when viewers will fully adopt this technology to broadcaster's standards. On the other side Samsung is widely promoting it's line of 3D capable TVs and aims to sell more than 2 million 3-D TVs this year and Panasonic has already came up with their affordable 3D productions gears for broadcasters. With all these vibes there is strong urge in the industry to produce more stereoscopic content for this new market that is ranging from music videos to military simulations.

Apart from all these general happenings it was very intriguing to dig deep into the technology itself and to see how it has transformed in the past few years. Stereoscopy is relatively a very old technology and people are being lured with this illusion since 1800s. I think most popular technology which we are all familiar with is Anaglyph Image where two images (left and right) are made up two colors (red and cyan) and superimposed to create illusion of stereoscopy when watched with same color coded glasses. Fortunately we have already come a long way from Anaglyph Images which caused motion sickness to us most of times.

According to Wikipedia, there are two technology for viewing stereoscopy images, mainly active and passive glasses. Active glasses technology needs an expensive wireless electronic glasses which is synced with the display screen and passive glasses uses polarizing filters on the projectors to project two images superimposed on to the screen. So for obvious reasons such as cost and practicality, Active glasses technology is moving more towards broadcast and PC gaming markets and passive glasses towards cinemas.

In cinemas, the most widely used technologies are by RealD and Dolby 3D. Both of them use slightingly different technology that falls under passive glasses technology. According to Wikipedia, The RealD Cinema system uses an electronically driven circular polarizer, mounted in front of the projector and alternating between left- and right- handedness, in sync with the left or right image being displayed by the (digital) movie projector.

Dolby 3D uses Infitec which stands for interference filter technology that splits the color spectrum into six narrow bands which then are divided into 2 in three primary color channels. This technology is a much superior form of Anaglyph technology.

There is also IMAX3D which use polarization technology similar to that of RealD.

As for a standardization, at the moment RealD is the clear winner in the race with the huge success of Avatar. According to, the company has net loss of 16.3 million from 23.4 million revenue in the year 2008 and for the year end of 2009, the company lost 20.3 million from 95.9 million revenue. Here is an image comparing both Anaglyph and polarizertechnology.

On the other side, broadcast and PC Industry are widely embracing Active glasses or Liquid Shutter Glass technology. Like I mentioned before in this technique liquid crystals are triggered in synchronization with the refresh rate of the screen allowing the glasses to alternately darken over one eye, and then the other. Screens also display different perspective for each eye using a technique called Alternate frame sequencing.

Nvidia is in forefront of this technology along with Samsung in PC gaming market while Samsung plans to dominate broadcast market and others like Panasonic and Sony are joining the trend. All of them uses the same technique ofalternative frame sequencing or time sequencing as mentioned above. It is important note that most of today's screens or monitor's support maximum of 80 hertz refresh rate but in order to support this high speed syncing with the active shutter glasses the screen should have a minimum refresh rate of 120 hertz.

Following is a Panasonic promotional video showing previous technology and advantages of current technology

Panasonic has also offers full 3D solutions from production to delivery, take a look at below video below and here is the link to their full production flow chart.

There are also other technologies in which you don't have to wear any glasses. These technologies comes under the category of Autostereoscopy. Uptil now most of these technologies are expensive and screen based so it may not ne easily adoptable for cinemas or main stream broadcast. One such technique is Pixel barrier where two images (left and right) are interlaced into the screen simultaneously.

Another similar technology is Alioscopy, where you have pixel barrier or filter to make the coded sub pixels a stereoscopic 3D experience. The real beauty of this technology is that it has 8 different perspectives so viewer could enjoy the true 3D experience from different angles. I have personally experienced this technology and found it truly an amazing experiencing but at the same time rendering 8 different views in full HD resolution would be extremely time consuming process.

With all these happenings it is so obvious that a good part of futur entertainment is going to be on 3D. I feel it is crucial to note that even though Stereoscopic 3D is not a new technology but only until Avatar that James Cameron showed us that this technology could be effectively used as a visual language rather than just a gimmick to attract audience.

Unfortunately in case of the films, a lot of production houses are looking at it as marketing tool to attract audience rather than taking it as a story telling medium and I think in broadcast media, stereoscopy is pushed in order to resurrect the penetration of HD into the main stream market considering only two broadcasters worldwide are fully HD now. According to Bill Schultz, co-CEO of Moonsoop Entertainment, L.A., "We have been doing HD for six or seven years, and there are still broadcasters who do not ask for an HD delivery,". So if Stereoscopic 3D becomes successful at least it will make sure that everybody goes HD.

I could be completely wrong here but personally, I don't feel like looking at stereoscopy as a future but instead I would like to see it as matured form of story telling medium because lot of people associate it with black & white to color or silence to sound transition in films. But from what I have seen and experienced, I think this technology has it's limitations compared to conventional 2D films and there are times where 2D might win over 3D films. For example, fast cuts of shots with different scale and depth might work pretty well with the conventional 2D film. But I think doing that sort of cuts in stereoscopic film in which the perception of deptsh changes very quickly between scenes may not be pleasing to your brain no matter how good the edit looks.

Since doing a Stereoscopic film would be technically superior I think a good example to relate what I meant would be, painting with water color and oil paint. You could pain beautiful paintings with both mediums but oil painting add whole new demension as well as technical limiations compared to water color. So it just the choice of the filmmaker that would call for Stereoscopy.

Micheal Bay is one of the director is who has been outspoken about his opinion on 3D as well as 2D to Stereoscopic 3D conversion. Micheal Bay says “The way I shoot is too aggressive for 3D cameras. It’s a time consuming thing,” said Bay. “Who knows… It might be a fad. I’m kinda old school. I’m old school because I like to shoot on film. I like anamorphic lenses, and that is old school.” I agree with him on the above statement and I think it relates to my previous example as well.

For the past few weeks I been testing stereoscopy at my workplace, so I will try to post more on this subject relating to workflow, aesthetic and story tellings aspects as I discover them.

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