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1953-54 Theatre Catalog, 11th Edition, Page 261 (225)

1953-54 Theatre Catalog, 11th Edition
1953-54 Theatre Catalog
1953-54 Theatre Catalog, 11th Edition, Page 261
Page 261

1953-54 Theatre Catalog, 11th Edition, Page 261

DIAGRAM OF transfer images from two negative films to single film carrying the two disparate images can be seen in the right column.

of studio production, shipping and handling costs between exchange and theatre, nor does it require dual projectors and added labor costs for projection. This single projection method does not introduce the unwanted possibility of images out of synchronism with each other, a hazard that exists in dual projection. It assures precise registration, one image with the other. Alignment is no problem, since both images are framed together by the same frame-setting lever. There can be no juggling or jittering between the images such as is present in any dual system no matter how well made the projector mechanisms.


The Friese-Greene Process

The first stereoscopic motion picture was made by William Friese-Greene who patented his process in 1893. He used two negative films, one behind each lens. The positive images were projected side by side on a screen and viewed through a cumbersome stereoscope permitting each eye to see only the picture intended for it. The complexity of this system barred it from any commercial application.

The Grid System

The grid system has been frequently proposed and a large number of variations on the basic method have been suggested during the past 40 years.

Basically, the grid system employs a screen containing a large number of vertically placed parallel opaque bars forming a grating having open or transparent spaces between them. This grid is placed some distance in front of the projection screen, the grating in the grid being designed s'o'that the right eye sees only that portion of the screen on which the picture record for the right eye appears, the bars in the grating hiding the left eye image from the right eye. It does the same thing for the other eye.

The chief problem in using the grid system is that the observers viewing distance, angle of view, and of eye placement in relation to the grid are of a fixed interlocking relationship. Disturb one of the three and proper viewing fails. A slight shift to the right or left results in the breakdown of "correct individual seeing" for each eye, and a double image become apparent, or else a pseudoscopic effect results. Improvements have been made on the basic grid system, but serious shortcomings still remain as an intrinsic part thereof. This particularly applies to the loss of light. While a light 105s is common to all stereo projection Systems, it is particularly severe in this one, due to the fact that the opaque areas in the grating have to be (in most cases) about three times that of the open areas in order to keep the images from overlapping.

Another matter that must be given consideration is the appearance of the grating to the observer. The dark bars and light spaces should be small enough to be virtually invisible as a banded pattern. To make the grating lines in 1953-54 THEATRE CATALOG



visible, the spacing of the elements should be no larger than about 1/3500 of the viewing distance. We shall call the grating space Gs. Then G..- 2 DV

3500 (or more)

Where D. is the viewing distance.

Thus, if D. : 60", Gs = .0175", approx.

And if DV 3 120", G... 3 .035", etc.

The distance, dg, of any selected grating in front of the screen depends on the relationship of the distance D.- to d, or by the relationship of I to D..

With the usual grid system, the picture through the grating is viewed by converging the eyes at or near the grating, forming an angle. In order for the grating effectively to select the images properly for the eyes, the disparate members of the stereoscopic pair must be projected through the grating at the same angle.

The New York Times, early in 1944, reported that Simyon Ivanov, a Soviet poster artist, had invented a screen made up of tiny squares of thousands of strands of fine wire which produced third-dimenseional effects without the use of eye-glasses. James Aldridge, writing on the same subject for the North American Newspaper Alliance, reported that the images reproduced through the screen were Ucoarse and blurred."

The article goes on to say that the original Ivanov grid system had been improved and developed in the ngintorgkino Studio to the point where it promised to become practicable. To quote from the article:

The glass screen is engraved with more than 2,000 converging lines, and it is in these markings that the secret of the new screen lies. In photographing third-dimensional movies, the only alteration required on standard cameras is the addition of two or more mirrors fitted near the lenses to reflect the images onto the film.

Obviously, this appears to describe Ivanovis photographic process as being an



application of the beam-splitter principle.

The article goes one to say:

In showing the film, it is projected onto ittwo or more mirrors," instead of directly onto the screen, which rehects the shadows onto the glass screen. In turn, the lines on the screen unscramble the images, resulting in a clearer image than has hitherto been obtained in thirddimensional film experiments.

Then, in October 1945, the Wall Street Journal reported further on the Ivanov development:

Moscow (APy-TheSoviet film industry is preparing a surprise for the world's movie fans-a special production of Robinson Crusoe to be exhibited on a new stereoscopic screen designed to give rounded, three-dimensional images.

Semeon Pavlovich Ivanov, the inventor, said that the screen creates an illusion so perfect that people unconsciously dodge when pictures of birds or airplanes

are shown. Ivanov said he believed the screen

surpasses anything Hollywood had done to achieve realism in the exhibition of motion pictures.

On April 29, 1948, the New York Herald-Tribune published the following:

Moscow, April 28 (AP)eThe Communist newspaper ftPravda" disclosed today that Semyon I): Ivanov, described as the inventor of three-dimensional motion pictures, had been removed from the job of scientific chief of the special studio in which he perfected the invention.

The newspaper (Pravda) said that I. Bolshakov, Motion Picture Minister, did not take Mr. Ivanovs work seriously, tried to picture him as a faker and publicity seeker and finally pulled him off with the excuse that he was freeing him from his administrative duties.

Pravda went on to state:

Thatls how the cinema industry freed itself of the worrisome individual whose name will go down in the history of the Soviet and world cinema.

1953-54 Theatre Catalog, 11th Edition, Page 261