From The TV IV
The original Cinerama system is a widescreen process which works by simultaneously projecting images from three synchronized 35 mm projectors onto a huge, deeply-curved screen, subtending 146º of arc. The screen is made of adjacent vertical strips, each of which faces the audience, in order to prevent light scattered from one side of the curve from impinging on the other side. The spectacular display is accompanied by a high-quality, six-track, stereophonic sound system.
The original system involved shooting with three synchronized cameras sharing a single shutter, but this was later abandoned in favour of a 65 mm system, shot with a single camera. (Aficionados, however, insist that the later processes were inferior.) Although one of Cinerama's single-film descendants, Ultra Panavision 70, used an anamorphic adaptor, neither three strip Cinerama or its other 65 mm descendant, Super Panavision 70, used anamorphic lenses, although 35 mm anamorphic reduction prints were produced for exhibition in theatres with anamorphic Cinemascope-compatible projection lenses.
Cinerama was developed by Fred Waller and was the outgrowth of many years of development. A forerunner was the triple-screen silent Napoléon made in 1927 by Abel Gance; Gance's classic was considered lost in the 1950s, however; it existed only by hearsay, and Waller could not have actually seen it. Waller had earlier developed an 11-projector system called "Vitarama" at the Petroleum Industry exhibit in the 1939 New York World's Fair. A five-camera version, the Waller Gunnery Trainer, was used during the Second World War.
The word "Cinerama" combines cinema with panorama, the origin of all the "-orama" neologisms. ("Cinerama" is also an anagram of "American.")
Cinerama was introduced in September, 1952, at the Broadway Theatre in New York.
The photographic system involved three interlocked 35 mm cameras equipped with 27 mm lenses, approximately the focal length of the human eye. Each camera photographed one third of the picture shooting in a criss-cross pattern, the right camera shooting the left part of the image, the left camera shooting the right part of the image and the center camera shooting straight ahead. The three cameras were mounted as one unit, set at 48 degrees to each other. A single rotating shutter in front of the three lenses assured simultaneous exposure on each of the films. The three angled cameras photographed an image which was not only three times as wide as a standard film, but photographed a wide angle image photographing 146 degrees of arc, close to the human field of vision, including the peripheral vision. The image was photographed six sprocket holes high, rather than the usual four used in other 35 mm processes. And the picture was photographed and projected at 26 frames per second rather than the usual 24.
The system had some obvious drawbacks. If one of the films should break and be repaired with the damaged frames cut out, the corresponding frames would have to be cut from the other two films in order to preserve synchronization. The use of zoom lenses was impossible since the three images would no longer match. Perhaps the biggest limitation of the process is that the picture looks natural only from within a rather limited "sweet spot." Viewed from outside the sweet spot, the picture is annoyingly distorted. But these problems certainly did not stop moviegoers from appreciating this innovative wide-screen process.
Worthy of note is the special Cinerama screen, which consisted of hundreds of separate vertical strips. This design eliminated cross-reflections on the deeply curved screen. Anyone who has seen the washed-out appearance of an IMAX Dome presentation will appreciate why this was important.