The motion picture projectionist (Nov 1931-Jan 1933)

18 Motion Picture Projectionist November, 1931 Fig. 2. Film Treating Machine This cleaning is done on machines such as are shown in Fig. 1. The film first passes through a cleaning solution such as trichlorethylene and is then brushed thoroughly, first on one side, then on the other. The brushes penetrate to the bottom of the scratches and remove dirt particles. The second step is a chemical treatment based on the swelling of the celluloid substances, and the liquefaction of the surface to a certain degree which permits the substances to penetrate into the picture layers. The swelling of the material thus effected varies from 21 to 36 per cent, depending on the type and make of film. The swelling, which at the beginning diminishes rapidly, only amounts solutions differing according to the nature of the film. In the impregnation treatment for preserving new film, the emulsion layer is subjected to a similar colloidal process. By means of this process suitable substances are intro W! Fig. 3. The Applicator to about half the quoted value after 48 hours; the loss of the liquid by evaporation then proceeds very slowly, so that even after a year a slight swelling may be in evidence. The chemical treatment is given in the machine shown in Fig. 2. The close-up, (Fig. 3) show details of the applicator cabinet. The applicator wheel is shown at the right. It serves to carry to the film the correct quantity of solution, which can be regelated within close limits. Both negatives and positives are treated in machines of the same type, the RCA Photophone Markets New Type Disc rITH approximately 4.000 theatres employing the disc method of sound reproduction as a market, and having arranged with 90 percent of the producers of sound motion pictures for the recording of their output, RCA Photophone, Inc., has begun the distribution of a new type of disc record which has been developed and perfected by the engineers of the RCA Victor Company at its plant in Camden, New Jersey. This new disc which is called the Victrolac Record, is an improvement over the old style of shellac record in a number of respects, with advantages that at once become apparent to the producers and no doubt will be welcomed by all exhibitors who still retain the disc method of sound reproduction. Among the important features which make this new record vastly superior to the old ai*e the reduction in size from 16 inches to 12 inches in diameter, the pronounced reduction in weight from 24 ounces to 4 ounces, its flexibility and durability, improved tone quality and a minimum of surface noise. An Important Development "The new Victrolac Record which was recently developed by the RCA Victor Company and which is now b«ing distributed by RCA Photophone, Inc., is one of the most important developments in the art of disc recording and reproduction that duced which form, with the gelatine, colloidal complexes of increased resisting power which retard the tendency of new film to shrink and which harden and make glossy the emulsion surface so that it can better resist mechanical attacks. This treatment also increases the elasticity of the film, particularly at the perforations, resulting in longer life. There is a very slight increase in the thickness of the film amounting to less than 1/20 of one per cent (about 0.002 mm.), a negligible amount. There is, however, no coating over the emulsion. The application machine is similar to the one shown in Fig. 2 and Fig. 3. Tests have indicated certain improvements when the film is impregnated. Elongation and tensile strength comparisons are shown in the table. These tests were made by the Prussian Government Material Testing Bureau. Film strips 10 cm. long were used. The perforations along each edge were cut off, making each strip 2 cm. wide. Standard testing apparatus was used to obtain the data for elongation and tensile strength. As can be noticed, a distinct improvements in elastic quality is characteristic of the samples of impregnated film. has been brought out in the past twenty years," said Mr. Lowell V. Calvert, manager of the Department of Recording Operations of the latter corporation. "It has so many advantages over the old type shellac record that the major producing corporations have accorded its introduction a most enthusiastic welcome. That it will be similarly received by the 5,000 or more exhibitors who retain disc equipment in their theatres, there is not the slightest doubt, especially in view of the fact that 90 percent of the producing corporations already have arranged with us to employ this record in transferring the sound tracks of their sound-on-film productions for disc reproduction. It will mean a considerable saving to them in the matter of express charges alone. "Not much thicker than a sheet of heavy paper or light cardboard and being practically unbreakable, the new record does not require the delicate handling that was necessary with the old shellac record. In spite of the reduction in size of the record from 16 inches to 12 inches, the 1,000 feet of film recorded is still maintained. This has been accomplished by employing a lower amplitude of recording, smaller grooves and the placing of the grooves closer together. On the old shellac record, there were 90 lines per inch. On the new, from 120 to 130 lines may be recorded. Victor 100 per cent shadowgraph inspected or chromium tipped needles are required for satisfactory sound reproduction."