3D Television - the technology
3D television is the latest hype in TV technology. 3D technology as such is not exactly new. Quite the opposite; 3D movies were fairly popular in the 1950’ies. Back then it was an attempt to lure the growing TV audience back into the cinemas. Since then 3D had its up and downs. Now and then new attempts were started but the benefits never compensated for drawbacks. Up until recently it was a niche then and limited to still pictures and cinemas.
It took forever to kick off then. Why now? In many ways the final breakthrough came with James Camerons blockbuster Avatar. For the first time a major release was filmed and produced with 3D in mind. The overwhelming success of Avatar is probably the single most important reason that you see all these 3D tellies on the shelves now. The industry owes him!
For the first time we now have interesting content, televisions with enough processing power to deal with the data and a device to store not only Full HD but also 3D films on one disk. Blue ray by the way is the only device to do this. There are no 3D movies on DVD. It looks like 3D is finally ready to hit mainstream.
So, how does it work then?
The concept is old. The principle of how to produce a 3D image has been discovered a long time ago. Most of us still remember the funny two coloured glasses. They worked. The result was 3D’ish but not particularly impressive. That has changed since. With modern technology you get astonishing results. The idea behind is still the same though: stereoscopy.
The principle behind is that two 2D pictures are being combined to create an optical illusion. Because they are taken from a slightly different angle they replicate what we normally do with our eyes and brain.
When we look at an object, left and right eye look at it from two different directions. Since our eyes are not all that far apart the difference isn’t massive, still there is a slightly different angle. The brain combines the two pictures and creates “depth”. 3D televisions use the same approach.
With the video stream two “half pictures” are delivered. The television splits them up and the glasses secure the distribution between left and right eye. When done the right way it gives the impression of stereoscopic vision. The result is the 3D effect. And that’s all it is. Despite the branding 3D television the picture is not real 3D. It is double 2D. What you see is nothing but an optical illusion. I couldn’t care less. What matters is the result.
In order to accommodate the current situation where you have 3D and 2D devices watching the same program the engineers came up with something called side-by-side video streams. You basically have two anamorph compressed video streams that a 3D device can decrypt and deliver as 3D; all others just see the regular picture. That’s pretty clever.
Proceed to the devices ...