Actually there are four different kinds of “formats”.
1) green/red
2) polarized
3) active shutter
4) screen masks
Number 1 is kinda the cheapest form in which you wear a green/red glasses. These will often also be included if you buy 3D DVD’s at this moment. The 3D effect is made by displaying green lines and red lines on the screen which will be filtered by the corresponding color in the glasses.
Number 2 is the one in cinema’s and the one that LG and other manufacturers use. In this case the 3D effect is made with using vertical and horizontal lines which are filterd by the glasses to the corresponding eye.
Number 3 is the one SONY uses and requires active shutter glasses which have to sychronize with your TV. The 3D effect in this case is made by displaying one frame for the left eye and the next frame is for the right eye and so on…. (Thats why one of the Bravia’s is 400Hz (200Hz per eye)).
Number 4 is not really used right now, because the technology is way from perfect. It requires no glasses, but you have to be exactly in front of your screen for it to work. The 3D effect is made by a mask over your screen, which will divert the light intended for the one eye to that specific eye. (That's why you have to sit in the center of the screen.)
The problems with number 1 and 2 is that you have to have an extra bright picture to be able to get the 3D effect and the glasses (especially the polarized) will filter the normal light around you too, which is the main source of the headaches some people get from watching that. Numbers 3 and 4 have the complete light spectrum available without affecting the 3D effect, which gives you more colordepth and more contrast.
Some of LG’s TV’s use passive (polarised) whereas other use active. Active is the ONLY way to get Full HD per eye. Either of which the TV will decode the PS3’s 3D imagery and output it how the TV likes (active or passive)
ALL of Sony’s 3D TV’s use active shutter.
