silver screen: In order to be able to use the polarization process, a silver-coated screen that reflects the light is required. When projecting onto a conventional white screen, it works polarization of the light is lost because the light is scattered on the surface of the screen, destroying the polarization. As a rule, however, conventional cinemas are equipped with a white screen.
The problem of the additionally required silver screen can be avoided if, instead of polarization, the alternating projection of the images for the left and right eye is used (i.e. not RealD is used). By using shutter glasses, which (controlled by infrared) alternately darken one and then the other lens, the conventional screen can be used, which makes showing the film easier and cheaper for the cinema. Even when using interference filter technology, the use of a silver screen can be dispensed with.