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1953-54 Theatre Catalog, 11th Edition, Page 258 (222)

1953-54 Theatre Catalog, 11th Edition
1953-54 Theatre Catalog
1953-54 Theatre Catalog, 11th Edition, Page 258
Page 258

1953-54 Theatre Catalog, 11th Edition, Page 258


lems since the cameras would not fit into any available studio tfblimps." However, the sequence was shot without any parasite camera noises being recorded, thanks to the intelligent help rendered by Walter Hicks, then of the New York Fox-Movietone Studios.

Since the Chrysler film was shot in a two-camera setup, and no special photographic and projection facilities for single-film handing was available, it was necessary to project with two projectors. A rather complex Selsyn motor drive was used for interlock, although a much simpler synchronization could have been attained by a straightforward mechanical linkage, such as was used for the Pennsylvania Railroad stereoscopic movie display at the Golden Gate International Exposition in San Francisco in 1940.

The dual projector system used at the New York and San Francisco Fairs is substantially the same as that recently on exhibition at the Festival of Britain. According to press reports, it is also the same system which has recently been demonstrated by the Natural Vision Corporation of Hollywood.

A Technicolor film, using the stopmotion technique as well as live action shots on monopack was our next stereo production. For the stop-motion sequences, a unique filter attachment was arranged in front of the camera lenses. The filters were mounted on wheels which rotated together. Color balance was attained by making sectors having .angular dimensions calculated to pass the quantity of light required for each color and as demanded by the sensitivity of the film. The SA" (red) filter passed light to which the film was more sensitive than that passed by the "B" (green) and th5" (blue) filters. Consequently, the red filter had the narrowest opening of all and the HC5", to whose transmission the film was least sensitive, had the widest opening. The exposures were made by the alternate frame method of color separation. Three frames, one the red record, one the green, and one the blue, were made instead of one frame as in ordinary photography. This procedure is followed in the photography of animated cartoons.

Those separation negatives were used by Technicolor to make the printing .matrices from which the dye imbibition prints were produced.

THIS DIAGRAM ILLUSTRATES THE principle of ' polarixodrlight stereoscopic projection.

It has always been the authors opinion that the stereoscopic camera for professional use should be built to take the images on two separate films. This is to afford the greatest fiexibility in the studio and to permit the use of short focus lenses and to facilitate the making of optical effects in the duplicating processes. One such camera was built. It contains the features deemed essential to a versatile camera. The most important are a variable interaxial and a convergence control, but important too is a binocular finder showing in miniature a three-dimensional View of the scene to be photographed. Visual inspection during focusing seems superior for stereoscopic work and focusing is easier when the view is seen in three dimensions. The binocular View finder has an additional advantage: it enables the cameraman to compose the scene stereoscopically using the interaxial and convergence controlsy manipulating them until he gets the best possible arrangement. He can increase the interaxial if he wants to increase the apparent depth of the scene. He can reduce it if nearby objects demand it.


Systems for stereoscopic films using dual images side by side or one above the other have also been proposed. One of the problems in the two-image arrangement, whether in tandem or side by side, is the loss of light, because the light-covering circle covers a large area around the area occupied by the two images.

The ordinary circular light spot from the projector arc spills light all around the images. This condition can be improved upon by a light condensing system having a cylindrical lens' element. Then the light spot becomes oval instead of round.




The Newcomer Anamorphoser

Another method is to introduce an optical device on the camera to compress the images in one direction, and a similar device on the projector to expand them back to normal proportions. Such an optical device is called an fianamorphoser." Several types have been constructed, but it remained for Dr. H. Sidney Newcomer to design one that does not introduce serious aberrations and have other optical handicaps. The Newcomer Anamorphoser is capable of effecting a compression of the image to almost two-thirds and an expansion of almost one and one-half times.

The Beam SpliHer

Among the methods suggested for the employment of a single film to carry the two images is the tfbeani-splitter" in one form or another. The device has two pairs of mirrors (or prisms) placed in front of the lens and arranged so that the pair on the left will cause the lefteye image to be selected for projection to the screen and the right-hand pair will do the same for the right-eye image. It is a simple device and easy to uSe.

The beam-splitter is a device that does exactly what its name implies; it splits the light beam into two parts. Hence, the intensity of each part cannot be greater than half of the whole beam. But in' addition to light loss, it has another drawback. The pictures overlap considerably, making it impossible to mask them to a stereoscopic window. The window must be artifically produced by a black border on the screen to absorb spill-over light. Another shortcoming: The camera lens works at something less than half the f/stop setting shown on the lens. This means more than twice the amount of light required for conventional photography. When it comes to shooting interiors, this added light requirement


1953-54 Theatre Catalog, 11th Edition, Page 258