3D video captures our world in all three dimensions: height, width and depth. The latter is what makes a 3D video so difficult to make. Humans can see depth without much effort because our eyes see slightly different from each other, and our brains interpret that difference as depth.
Modern 3D technology tries to mimic this process by showing different versions of the same video to each eye. The difference is not big, but it’s enough to trick the brain to think that we are seeing depth in a video. This process is however not totally perfect. That is why we still need 3D glasses that help the brain to reconcile the two versions of the video in the right way.
Making of a 3D video requires skills and resources. Typically, you need two cameras and other special equipment to shoot a video in 3D, which all can be very costly. Today it’s also possible to transform a 2D video into a 3D video, but the results are usually less sharp.