Glasses-free 3D: eventually someone is going to get this right. Researchers in South Korea are well on their way, which means we might eventually be able to watch a 3D movie without having to wear those dorky, uncomfortable glasses.
Currently, you have to wear specs in a film like Avatar so that two separate images can come together to create one 3D image. In the cinema, there are two projectors playing two different movies behind the audience, and the glasses help you see them as one. To ditch the specs, a projector would have to be behind the screen, and most theatres don't have the money or the equipment for that -- until now:
The new method would allow movie theatres 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.
Of course, 3D has more problems than just goofy glasses; it's also a horrible, garish novelty. But at least this way your eye-rolling won't be hidden behind a stupid pair of shades. [Optics Express via Wired]