New movie display allows for glasses-free 3D for a theater audience

A new “Cinema 3D” display lets audiences watch 3-D films in a movie theater without glasses. Developed by a team from MIT’s Computer Science and Artificial Intelligence Lab (CSAIL), the prototype display uses a special array of lenses and mirrors to enable viewers to watch a 3-D movie from any seat in a theater.
Glasses-free 3-D already exists: Traditional methods for TV sets use a series of slits in front of the screen (a “parallax barrier”) that allows each eye to see a different set of pixels, creating a simulated sense of depth.
But because parallax barriers have to be at a consistent distance from the viewer, this approach isn’t practical for larger spaces like theaters, which have viewers at different angles and distances. Other methods, including one from the MIT Media Lab, involve developing completely new physical projectors that cover the entire angular range of the audience. However, this often comes at a cost of lower image-resolution.
The key insight with Cinema 3D is that people in movie theaters move their heads only over a very small range of angles, limited by the width of their seat. So it’s enough to display images to a narrow range of angles and replicate that to all seats in the theater, using a series of mirrors and lenses. (The team’s prototype requires 50 sets of mirrors and lenses, which is currently expensive and impractical, the researchers say.)
The team presented Cinema 3D in an open-access paper at last week’s SIGGRAPH computer-graphics conference in Anaheim, California. The work was funded by the Israel Science Foundation and the European Research Council.