Ever try to watch a 3-D movie without those special glasses? You may think you're seeing double! Well, guess what. You are!
Normal movies are shot with one camera. Three-dimensional movies are shot with two cameras, or one camera with two lenses. The cameras are placed side by side, about as far apart as the distance between your eyes. Each camera shoots the same picture, but from slightly different angles.When you see a 3-D movie, the film from both cameras is being shown on the screen at the same time. That's why you see double without the glasses. You're seeing both images, says 3-2-1 Contact magazine.
The trick is to get your left eye to see the film shot from the left camera and your right eye to see the picture shot from the right camera. To do this, special filters are used. The filter allows each eye to see only one image. Then your brain thinks you're seeing as you normally do, and it creates an illusion of depth.
Where do these filters go? On your eyes! The filters are the weird glasses you wear at a 3-D movie.