| IMAX |
From: http://en.wikipedia.org/wiki/Imax
The intent of IMAX is to dramatically increase the resolution of the image by using much larger film stock at a resolution of 38720 x 24120. To do this, 70 mm film stock is run "sideways" through the cameras. While traditional 70 mm film has an image area that is 48.5 mm wide and 22.1 mm tall (for Todd-AO), in IMAX the image is 69.6 mm wide and 48.5 mm tall. In order to expose at standard film speed of 24 frames per second, three times as much film needs to move through the camera each second.