70 mm film
70 mm film (or 65 mm film) is a wide high-resolution film gauge for motion picture photography, with a negative area nearly 3.5 times as large as the standard 35 mm motion picture film format. As used in cameras, the film is 65 mm (2.6 in) wide. For projection, the original 65 mm film is printed on 70 mm (2.8 in) film. The additional 5 mm contains the four magnetic strips, holding six tracks of stereophonic sound. Although later 70 mm prints use digital sound encoding (specifically the DTS format), the vast majority of existing and surviving 70 mm prints pre-date this technology.
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Each frame is five perforations tall, with an aspect ratio of 2.2:1. However, the use of anamorphic Ultra Panavision 70 lenses squeezes the image into an ultra-wide 2.76:1 aspect ratio. To this day, Ultra Panavision 70 produces the widest picture size in the history of filmmaking; surpassed only by Polyvision, which was only used for 1927's Napoleon.
With regard to exhibition, 70 mm film was always considered a specialty format reserved for epics and spectacle films shot on 65 mm and blockbuster films that were released both in 35 mm and as 70 mm blow-ups. While few venues were equipped to screen this special format, at the height of its popularity most major markets and cities had a theater that could screen it. Some venues continue to screen 70 mm to this day or have even had 70 mm projectors permanently or temporarily installed for more recent 70 mm releases.