Operation of current 3D cinemas
As already mentioned, the technique used interfered with the visualization of colors, so it was necessary to develop a better technology, but more expensive and complicated, but that does not affect the original colors. This new technology is based on the polarization, being now the glasses made by dark lenses and no longer colored as before.
So let's see how today's 3D cinemas work.
To obtain the images, two cameras are used: one for capturing images for the right eye and the other for capturing images for the left eye. Thus, the image will be more "real" or "off-screen" the further the distance between the image and the screen.
Because two cameras are used, the film will have 48 frames per second, equivalent to twice the frames used in conventional films, 24 of them being observed by the right eye and the other 24 by the left eye.
The overhead light reaches the spiral screen and the frames alternate as part of them rotates in one direction while the other part rotates in the opposite direction. What's more, the screen is reflective (silver), which makes it possible for light to convey the idea that it is not a normal screen.
The glasses have polarity filters, allowing each eye to receive a frame, as if each person sees the same thing through two different focuses.
Obviously, the distance between the two eyes makes us see the same thing from different angles. Thus, it is based on these two images seen by each eye that the brain acts as if it "deceives" us and forms a third image, giving the impression of depth to the scene.