Modern cinematic 3D relies on circular polarization to separate the views. Which is why you have to wear special 3D movie glasses that are circularly polarized. These 3D glasses create the correct view in each eye. Typically, one lens is horizontally polarized and the other one is vertically polarized, which each eye sees a slightly different version of the movie screen. When the eyes attempt to join the two images for the brain, the result is a 3D image illusion.
The projector uses a polarizing filter that spins in front of the camera lens to help achieve the 3D effect. The circular polarization effect that sends different color wave lengths to the the screen, are then filtered by the 3D Polarized Glasses you are given when you come to the theater.
The last piece to the puzzle is the screen. In order to make this polarization work, standard white projection screens won’t work. The screen must have a silver coated, semi-reflective screen that allows for the polarization effect to be received by your 3D glasses.
Resources on 3D Media and Polarization:
- What are Polarized Sunglasses?
- See Me Media: What It Takes to Show a 3D Movie
- Circular Polarization
- Rainbow Symphony: How Polarized 3D Glasses Work