3D films like Avatar trick your brain, bringing images projected onto a flat cinema screen to life in full three dimensional glory.
If you look at an object near you and close your left and right eyes in turn, you’ll see that each has a slightly different view of the world. Your left eye sees a bit more of the left side of the object, and your right eye sees a bit more of its right side. Your brain fuses the two images together allowing you to see in three dimensions. This is known as stereoscopic vision.
To create a similar effect, 3D films are captured using two lenses placed side by side, just like your eyes (or by producing computer generated images to replicate the same effect).
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