70 mm film

70 mm film (or 65 mm film) is a wide high-resolution film gauge, of superior quality to standard 35 mm motion picture film format. As used in camera, the film is 65 mm wide; for projection 2.5 mm are added along each outer side of the perforations for magnetic strips holding six tracks of surround sound, although more recent 70 mm prints now use digital sound encoding; however, the vast majority of 70 mm prints predate this technology. Each frame is five perforations tall, with an aspect ratio of 2.20:1. However, there are many theatres unable to handle 70 mm film, and so 70 mm films are shown in 35 mm at these venues, in the regular Cinemascope aspect ratio of 2.35:1. Film formats with a width of 70 mm have existed since the early days of the motion picture industry. The first 70 mm format was most likely footage of the Henley Regatta, which was projected in 1896 and 1897, but may have been filmed as early as 1894. It required a specially built projector built by Herman Casler in... full article at wikipedia