Now a team of researchers from MIT’s Computer Science and Artificial Intelligence Lab (CSAIL) and Israel’s Weizmann Institute of Science has developed a display that allows viewers to watch a 3-D movie from any seat in a theater—without the glasses.
The prototype device, called “Cinema 3D,” employs a special array of lenses and mirrors; although it is not ready to hit the market yet, the team looks forward to future versions that could propel the technology forward to a place of glasses-free 3-D movie viewing.
“Existing approaches to glasses-free 3-D require screens whose resolution requirements are so enormous that they are completely impractical,” says Wojciech Matusik, one the MT co-authors on a related paper. “This is the first technical approach that allows for glasses-free 3-D on a large scale.”
How It Works
While glasses-free 3-D technology already exists, it is not in a way that allows it to work in movie theaters. The technology usually works on a TV via a series of slits in front of the screen called a “parallax barrier” that allows each eye to see a different set of pixels and create a sense of depth.
Parallax barriers have to be at a consistent distance from the viewer, so this approach is not deployable in larger spaces like theaters where viewers sit at different angles and distances.
There have been other methods developed too. One out of the MIT Media Lab involves implementing new projectors to cover the entire angular range of the audience. However that method could result in reduced image resolution.
With CSAIL’s Cinema 3-D method, multiple parallax barriers are encoded in one display so that each moviegoer can see them from any position. Then the range of view is recreated across the theater with the mirrors and lenses that make up the technology’s optics system.
According to Assistant Professor Gordon Wetzstein from Stanford University, who was not involved in the research, when using a 3-D TV, it is important to take into consideration that people will be moving around or watching it from different angles.
“Which means that you have to divide up a limited number of pixels to be projected so that the viewer sees the image from wherever they are,” said Wetzstein. “The authors [of Cinema 3D] cleverly exploited the fact that theaters have a unique setup in which every person sits in a more or less fixed position the whole time.”
The team has shown that its approach allows viewers from different areas of a room to consistently see high-resolution images.
While the prototype is a clever idea, the Cinema 3D system is not yet practical because it still requires 50 sets of mirrors and lenses, while only being a little bigger than a pad of paper. The team hopes to build a larger version of the display and to further refine the optics to continue to improve the image resolution.
“It remains to be seen whether the approach is financially feasible enough to scale up to a full-blown theater,” says Matusik. “But we are optimistic that this is an important next step in developing glasses-free 3-D for large spaces like movie theaters and auditoriums.”