How Do IMAX Theaters Project in 3-D?

Imax theaters use special projectors and film to cast two special copies of the same images onto a silver-coated Imax 3D screen. Most of the technology at every stage of the process is proprietary, so Imax is the only company responsible for its brand of cameras, projectors, film and screens.

Imax 3D begins with Imax 3D cameras, which record images through two lenses set apart at roughly the distance between a pair of human eyes. After the Imax 3D projector casts these two distinct, overlapping images simultaneously onto the same Imax screen, Imax 3D glasses separate the image, while the viewer's brain blends the image into one with depth and dimension.

Imax refers simultaneously to a technology and the company that creates it. Imax technology uses larger film and projectors to create oversized images on movie screens. Imax films are typically shot on 65-millimeter film and then printed on 70-millimeter film, as compared to the standard size of 35 millimeters. The wider film results in a brilliantly sharp negative that contains more nuanced, precise color and yields greater resolution and images that do not lose clarity when projected onto a larger surface.

Imax cameras and projectors contain special lenses. The projectors, which are unique to Imax, also use vacuums to pull 70-millimeter film with 15 perforations per frame over platters, rather than reels, while the projector's shutter remains open roughly 20 percent longer than that of smaller, more traditional projectors.