What is the imaging principle of 3D movies? Why does a plane have a three-dimensional effect?

How are stereoscopic images generated? Mainly through the 3D converter, the input stereoscopic 3D signals are converted into two passive 3D output signals, which are respectively output to two projectors as left and right eye signals, and viewed through polarized 3D eyepieces, thus obtaining stereoscopic images. Because the signal is actively converted by 3D converter, this technology is also called active stereoscopic imaging technology (different from the passive stereoscopic imaging technology we will mention later). In other words, without stereoscopic glasses, the images we see with the naked eye are displayed by our left and right eyes respectively, which is a common diplopia phenomenon. Therefore, 3D glasses are essential to watch a stereoscopic movie.

Because the signals of the left and right eyes are separated when people watch stereoscopic images, in order to avoid the unsynchronization of the signals of the left and right eyes (which is easy to cause image dislocation), it is necessary to synchronize the signals of the left and right eyes with the help of a signal synchronization transmitter to ensure that the images seen by the human eyes are left and right, that is, stereoscopic.

So why do you need a professional projection screen to present a clear stereoscopic image? Because the image seen in the cinema is composed of a lot of reflected light produced by the projector projecting on the screen. However, some of the reflected light is effective, that is, it allows us to see the image, while the other part is harmful (equivalent to the white reflected light generated by green leaves in strong sunlight, which will interfere with our eyes and make us unable to see the leaves clearly, resulting in dizziness), while the metal screen with polarization characteristics eliminates the harmful reflected light by adding special materials, thus ensuring that the effective light reflected by the picture to the human eye will not be disturbed. That is to say, the projection screen with polarization characteristics can filter harmful reflected light.