International projectionist (Oct 1931-Sept 1933)

November 1931 INTERNATIONAL PROJECTIONIST 41 reproduced sound in the smaller theatres. A lamp for slitless sound reproduction has been devised by Dunoyer. Essentially the lamp consists of a cylindrical glass bulb having a flat piece of optical glass sealed in one end exactly parallel with a tungsten filament 25 mm. long and 0.1 mm. diameter. The filament is made in such a way as to be perfectly rectilinear at its normal temperature of 2290°K. The image of the filament falls on a triplet anastigmat lens which at a magnification of 8 gives a scanning zone of 3 mm. length by 0.0125 mm. width. Non-Intermittent Projection. A nonintermittent projector for very thin (cellophane) film was demonstrated successfully in Madrid, Spain. The film has a row of perforation along one side and the sound track is printed along the other border. Since the film moves continuously, the sound record does not have to be displaced from the picture but runs alongside each picture. Screens. A new sound screen recently demonstrated in London consists of a special fabric upon which small semiparabolic lenses %-inch in diameter are mounted with a special light reflecting cement. The spaces between the lenses are cut away. A screen 22 ft. by 17 ft. carries about 460,000 lenses. In a new type of reverberation meter supplied by Electrical Research Products, Inc., sound energy is converted to electrical energy and a series of points are recorded on a waxed paper drum which give graphically the exact history of the sound decay. Television Systems. Short has published details on a television direct pickup camera, in which the image of the person being televised is focused directly upon spiral number one of the scanning disc. The camera is mounted on a rubber-tired truck which runs under its own power. Detailed movement of baseball games, tennis matches, and airplanes in flight have been followed easily with the apparatus, and it is possible to move quickly from a "close-up" to a "longshot." At the end of each scanning cycle in the Barthelemy system, the beam is interrupted a very short time. These lapses produce a 480-cycle frequency, which, filtered by an ingenious amplifying circuit, is used to operate a synchronous motor which drives the receiving scanning disc. A 3-watt lamp is used for a picture area of 600 sq. cm., as opposed to a 250-watt lamp for a 6 sq. cm. area in certain other systems. Color Cinematography. A new additive screen process of three-color cinematography was demonstrated successfully before the Royal Photographic Society in May, 1931. The manufacture of the film has been described by Periera, who states that 1,000-foot lengths of aceto-cellulose nearly 2 feet wide, are ruled with a three-color screen so that about a half milion squares cover each 35 mm. frame. A coating of collodion stained green is put on the base and a greasy ink resist applied to the surface by means of an engraved steel roller. A International Photographer Is a finely printed and beautifully illustrated monthly magazine owned by the West Coast Cameramen's Union In all matters concerning the professional motion picture photographers of the country it is the official organ It is designed to appeal to amateur followers of 16mm. cameras as well as to the most advanced technicians The columns of the magazine recognize the close relationship between the photographer and sound recorder If your news or kodak dealer does not carry the magazine on its counters write for a sample copy to INTERNATIONAL PHOTOGRAPHER GEORGE BLAISDELL, Editor 1605 North Cahuenga Avenue, Hollywood, Calif. 25 cents a copy $3 the year bleaching bath then destroys the green dye where it is not protected. A red line screen, and finally a blue screen are next coated in an analogous way, as the first screen. A special panchromatic emulsion of large sized grains is used as the last coating, so that on reversal of the negative, a fine-grained positive is said to be obtained. A projection method of making duplicates is said .to have been perfected. New Device to Solve Fresh Print Problems To eliminate blurring of new film by oil that projectionists put on new prints which have a tendency to pull sprocket holes on first and second showings, N. M. LaPorte, of the research department of Paramount-Publix, is cooperating with the organization responsible for the processing work for that company. "Within a few weeks, according to LaPorte, a mechanism which is expected to go far in solving this problem will be added to the processing unit. "A careful check on a questionnaire form sent out to the field indicates very clearly that damage to prints is caused on the first or second showing," said LaPorte. "The answers state that great difficulty is experienced in getting new prints to run freely through the projectors unless the projectionist squirts oil on the film.