A New Way of Doing Large-Format 3D – Without Glasses

Two research teams, working together have demonstrated a large-scale autostereoscopic 3D display, which can be used for watching 3D films without resorting to wearing special glasses.

The ‘Cinema 3D’ prototype was worked on by teams from MIT’s Computer Science and Artificial Intelligence Lab (CSAIL) and Israel’s Weizmann Institute of Science. It uses an array of lenses and mirrors to enable the 3D effect from any view.

MIT professor and report co-author Wojciech Matusik said, “Existing approaches to glasses-free 3-D require screens whose resolution requirements are so enormous that they are completely impractical… This is the first technical approach that allows for glasses-free 3-D on a large scale.”

TVs use a parallax barrier for 3D, but this is not practical in larger spaces as viewers are all sitting at different distances from the screen. Rather than using a single parallax barrier, Cinema 3D encodes multiple barriers in one display. Each viewer then appears to view the image through a barrier tailored to their position. The range of views is replicated across the auditorium by a series of mirrors and lenses.

Key to the development was the teams’ realisation that people watching films in cinemas only move their heads over a very small range of angles, limited by their seat width – unlike 3D TVs, where viewers can stand up and move around the room. Because of this, they calculated that they could display images to a narrow range of angles and replicate it to all seats. Resolution is kept ‘consistently high’, the teams said.

The existing prototype uses 50 sets of mirrors and lenses, and is barely larger than a sheet of paper. In theory, however, it could work in any large-format 3D context, including billboards and storefront adverts.

Matusik said, “It remains to be seen whether the approach is financially feasible enough to scale up to a full-blown theater.”