The Cine Technician (1953-1956)

September, 1953 THE CINE-TECHNICIAN 119 How three-dimensional pictures are obtained for television. Dual cameras pick up the images, but each method employs a different plan for viewing to gain the 3-D effect. (From " Tele-Tech "). STEREO TV (RCA A DuMo Polar. itd glosses for vie* Uses: 2 TV cameras 2 polarized picture 1 semi-reflecting mi SPLIT IMAGE TV Opaque separator for Uses: 2 TV cameras 1 picture tube SYNCHRONIZED SHUTTER TV (American TV) Rotating shutter viewer Usee 2 TV corntrat 1 picture tube 1 electronic switch in sync with _f* The output of the two sides is 20ft. per minute and 22ft. per minute respectively. The only other motion picture process being operated on a production scale in France is Realcolor. This is a two-colour process of Spanish origin, developed by Daniel Aragones. The Aragones camera uses a similar layout to the technicolor camera, with a beam-splitter behind the lens and two gates at right-angles. However, only two films are used, either Plus X or Super XX, with the appropriate two-colour analysis niters in front of each gate. A lighting level of 250 footcandles at f/2 is needed for Super XX and 400 footcandles for Plus X. Edge guiding only is used in contrast to the pilot pin registration generally considered essential in three-colour cameras. The negatives are developed in normal black and white negative developers to a gamma of about 0.65. The Realcolor two-colour prints are made on standard black and white fine grain positive stock and this is handled in two stages. The unexposed positive is dyed with a yellow dye either in manufacture or as a first step in processing. This yellow dye restricts the penetration of the exposing light, enabling the single thickness of emulsion to be used to provide two-colour images. The positive film is first printed in the normal way, emulsion to emulsion, from the red-orange filter negative and developed to black and white, turned cyan, bleached, and partly fixed. Adequate washing is of course essential between these stages. The film is then given a second treatment with the yellow dye to prevent the second exposure affecting the front of the emulsion. After drying the film is printed through the blue-green record negative through the base of the positive and developed in a special developer. This image is then fixed, mordented, and treated with two dyes, red and yellow successively, to give an orange-red image. As with any two-colour process reproduction of true yellows and violets is not possible, but within these limits the process is capable of a pleasing colour reproduction. As silver separation negatives are used, mixes, fades and other " opticals " are perfectly simple to produce, and the overall definition is good. Bauchet have made test coatings of Gasparcolor on motion picture stock. In view of the fact that Gasparclor is designed to give a positive from a positive, the prints on this film would have to be made from separation positives made from a colour negative, such as Eastman colour or Gevacolor. Attempts to use materials commonly available for black and white to produce colour films have not been conspicuously successful in other countries and in France, as in America, it seems likely that as monopack materials become more plentiful these processes will be used exclusively. The only exception to this would seem to be Technicolor. It is reported that Gaumont and Pathe of France are studying with Technicolor the possibility of the establishment of a laboratory in the Paris area. THE CROWN THEATRE Provides Complete Studio Projection Service at Any Time to Suit Your Requirements DOUBLE HEAD PROJECTION MIXING PANELS FOR TRACKS also SUB-STANDARD PROJECTION SEATING FOR 70 PERSONS SOUND SYSTEM ALSO THREE EDITING BAYS 86 Wardour St., London, W.l Tel: GERrard 5223 Editing Bays: GERrard 9309