International projectionist (Jan-Dec 1935)

18 INTERNATIONAL PROJECTIONIST July 1935 the film. Rib heights shall be slightly less than the height of the peripheral rolled edge to allow for stacking. All flanges shall be free from warping or buckling after assembly and shall run true within 1/32 inch when the reel is spun on a 5/16 inch shaft. Center bushing shall fit solidly into side flanges without looseness when assembled, and shall be of sufficient strengh to withstand the wear and tear of usage. Clinching ears shall fit tightly and shall be pressed down firmly so as to make a solid assembly of the reel and to insure at all times a 1/16 inch slot for threading the film end into the hub. Material shall be steel with anti-corrosive plating or coating, or non-corrosive alloy. Finish shall be suitable to protect against the wear of use and against the corrosion of ordinary atmospheric influences. To allow for the utmost freedom in design of the reel, maximum and minimum dimensions are indicated on the drawing wherever possible but where such values are not shown, the specific dimensions shall be strictly adhered to within the limits of good practice. Weight and Cost The total weight of the reel and its cost price must be closely comparable to two first class reels of 1000 feet film capacity. Any cheapness in the reel made possible by weak construction shall be deemed unsatisfactory. However, since the reels are intended only to remain in good condition for a sufficient length of time to last the life of the picture, a reasonably thin material may be used provided the flanges are well ribbed to maintain stiffness. Any concentric grooving in the flanges which will permit layers of film to shift laterally shall be considered unsatisfactory. Enamel or paint finishes are not recommended and unless they offer exceptional resistance to wear and chipping shall be considered unsatisfactory. Any reel on which the plating or dipped finish cracks during forming or assembling shall be considered unsatisfactory. Theatre Reproduction and Color Feature S. M. P. E. Progress Report The Cameraman UNSUNG heroes of successful film productions are cameramen. If the public ever thinks about the photographers at all, they simply believe they turn a crank or push a button to operate the camera's motors. Instead, the whole complex business of picture making devolves, in the final analysis, upon the man behind the lens. Story, acting, talent and directorial ability mean nothing unless they are painstakingly captured in celluloid. And when production executives occasionally find themselves "stumped" in obtaining special effects, they know that somehow or other their cameramen will provide the proper answers. —Karl Freund. PERHAPS the most needed piece of equipment in the industry is a silent camera. The leading camera manufacturers are working hard, but are not yet able to supply the industry with a camera that fulfills the sound and weight requirements of the studios. In the meantime each studio has been working industriously toward further perfecting their "blimps" by making them quieter and of lighter weight. Some of the "blimps" are sufficiently quiet to meet the most stringent demands of the sound departments, but the weight has been reduced comparatively little, leaving a real need for a one-man unit. Zoom lenses have made great advances during the past year and, although not yet perfected, a zoom lens can be expected in the near future that will operate at an //2.3 speed from a 35-mm. angle to a 150-mm. angle, making possible a single lens doing the work of at least six lenses of the present type. Projection or transparency background work has nearly attained perfection during the year. The hot spot, though it still exists, has become a minor difficulty ; perfect synchronization and matched lighting have blended composites into a much more beautiful whole than was ever before possible. Improved technic has widened the scope of transparency projection until "location trips" have become one-man jobs, the cast restricting their trips to the studio stage, a large piece of ground glass furnishing the requisite locale of desert, mountains, or foreign countries. Excellent results have been obtained recently. Color Spurs Carbon Use The interest in carbon arcs for studio lighting is quite pronounced at the present time, due to the new Technicolor pictures. In order to render the operation of the arcs sufficiently quiet for sound pictures, L. Kolb, of M-G-M, recently built a number of choke-coils of 1000-ampere capacity. Similar coils were built by Mole-Richardson Co., Inc. Each coil contains 300 feet of 1,000,000 circular mil. copper cable, making 36 turns, and has an air core. Such a chokecoil has the advantage of taking care of a large number of arc lamps from its position near the power-house. The ordinary choke-coil, made for individual lamps, must be carried to the motion picture set and located near the lamp it serves. Along this same line, the W. C. Hollins Electric and Engineering Company of Los Angeles has developed a dry type of electrolytic condenser to replace the regular electrolytic condensers in present use in the studios. Each unit weighs approximately 25 pounds, and has a capacity of 2,500 microfarads. One unit is sufficient for each end of a generator. These condensers are used in conjunction with choke-coils to eliminate commutator ripple. The advantages claimed for the "dry type" condenser are lightness of weight, no care is needed, lowness of price. They have recently been installed in several of the West Coast studios. There was no outstanding accomplishment in the field of new sound recording equipment during 1934, because major equipment suppliers were embroiled in litigation over the Tri-Ergon patents and hesitated to go ahead with new equipment lines until these patents were finally settled one way or the other. Considerable attention was given by the public to the sound recording in Columbia's One Night of Love, featuring. Grace Moore. This picture marked the initial attempt to use the new vertical cut recording system in sound pictures. The songs and orchestral selections were first recorded on wax and later transferred to film in the re-recording process. This gave a final film indistinguishable from an original film recording and superior to a film-to-film re-recording. RCA Sound Improvements A new system of recording on film was demonstrated which should serve to improve the fidelity and reduce the background noise of the extended frequency range of musical recordings. The new method can be employed for original recordings that are to be re-recorded for making final negatives. The original recording may be made either in the form of a positive which is almost completely exposed throughout the sound-track area, or in the form of a negative from which prints can be made for reproduction. The sound-track is divided into two parallel sections, each being exposed on only onehalf of the sound wave. One portion of the sound-track is then a record of negative half-cycles, and the other of the positive half-cycles. For silent intervals, there is practically no exposure when making positives. No biasing system is required, as with the noiseless recording systems used at the present time; it will still be required for making negatives from which release prints are to be made. In reproduction, the light on each track is impressed upon separate photo-cells or separate cathodes of a single cell. The cathodes are connected to opposite ends of a transformer winding. Imperfec(Continued on page 22)