Can 3D Movies Trick Your Brain?

Can 3D Movies Trick Your Brain?

HowItWorks.com

3D films trick your brain, bringing images projected onto a flat cinema screen to life in full three dimensional glory. But how do these great movies work?

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, according to physics.org.

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). The 3D glasses you wear filter those images, making sure they’re interpreted correctly by your optical sensors, according to By Adrien-Luc Sanders, who claims to be an animation expert through about.com.

As with old fashioned 3D, the film is recorded using two camera lenses sat side by side. But in the cinema, the two reels of film are projected through different polarized filters. So images destined for viewers’ left eyes are polarized on a horizontal plane, whereas images destined for their right eyes are polarized on a vertical plane. Cinema goers’ glasses use the same polarizing filters to separate out the two images again, giving each eye sees a slightly different perspective and fooling the brain into ‘seeing’ the setting of the movie as though they were actually there, according to physics.org.

But a new method is developing, one that won’t need the glasses. The new method would allow movie theaters to keep their projectors where they’ve always been, behind the audience, and uses fairly simple optical technology. A special array sits in front of the projector and polarizes its light. A filter covering the screen then obscures different vertical regions of the screen, like the slats of venetian blinds. Each of your eyes, sitting at a slightly different angle, has some of the screen blocked and some of the screen visible. The movie has the right-eye and left-eye images interleaved in vertical columns with one another. The trick then is to have the light visible to your left eye contain the left-eye pixels and vice versa for the right eye, according to CNN.com.