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1950-51 Theatre Catalog, 9th Edition, Page 344 (322)

1950-51 Theatre Catalog, 9th Edition
1950-51 Theatre Catalog
1950-51 Theatre Catalog, 9th Edition, Page 344
Page 344

1950-51 Theatre Catalog, 9th Edition, Page 344

advancing the 35mm film six perforations at a time instead of the customary four. Although the total amount of picture film used is four and a half times as much as that needed to make the conventional movie, the field of vision covered is approximately 1460 wide and 550 high almost comparable to the extreme 1600 by 750 range of human eyes.

Sound System

The field equipment for making Cinerama movies also contains a soundrecording outfit, which uses six omnidirectional microphones to pick up all the sound from every angle that exists in the area being pictured, including the sections to the sides and behind the camera. The sound is recorded on a magnetic type film, which needs no laboratory processing and can be played back at once.

Speakers in the theatre, arranged in the same pattern as the microphones, are individually operated by the six sound

tracks placed side by side on the aforemenioned smgle strip of sound film. As a general rule, five microphones and speakers are set in a row across the full width of the picture set and the theatre screen, respectively. The sixth microphone is placed some distance behind the camera to pick up Hoif stage" sounds, while the last speaker is located in the rear of the theatre to reproduce them.


The Cinerama system requires three projection booths and machines to project the three sections of the picture side by side on a semi-concave screen almost six times as large as the conventional motion picture one. As mentioned previously, the 146D width and 550 height. of the screen cover most of the area which the human retina does. As a result, the eye is permitted to exercise its peripheral vision, which provides the brain with its most important clues to

third-dimension or spatial relationships.

The center section of the screen is usually curved on a 25-foot radius, and two Hat wings run tangential to this curve. This curvature does not present a real problem in projection, for the focus depth of the lenses is sufficient to overcome any such contingency. The scce tions on either side of the center are ribbed vertically to eliminate any possible reiiection of light from the ends to the middle.

Each projector contains a novel mechanical device with a sawtooth edge which moves along the border of a film, so that the image slowly fades from view at its edge. Adjoining films are thus blended together on the screen without a noticeable dividing line.

SECTION OF DIAGRAM BELOW illustrates how a Cinerdmu show would appear on a special theatre screen and the equipment needed tor its presentation. The three projectors throw the three sections at the picture side by side on the screen. while the five speakers behind. and a sixth in the rear of the house. carry the sound.

1950-51 Theatre Catalog, 9th Edition, Page 344