RG Specs

To create the illusion of three-dimensional depth, the IMAX 3D process uses two camera lenses to represent the left and right eyes. The two lenses are separated by an interocular distance of 64 mm (2.5 in), the average distance between a human’s eyes. By recording on two separate rolls of film for the left and right eyes, and then projecting them simultaneously, viewers experience seeing a 3D image on a 2D screen. The IMAX 3D camera is cumbersome, weighing over 113 kg (250 lb). This makes it difficult to film on-location documentaries.

via IMAX – Wikipedia, the free encyclopedia.