The motion picture projectionist (Nov 1929-Oct 1930)

16 The Motion Picture Projectionist December, 1929 o a a a a 22/t. wmN a a a a a ■48 mm a a a a a a a o n a a □ a a a a a o a a a a a a a a o a a a a a a a < }■ 35i«.vn 1 — ^ O a a a aivmn Diagrammatic representation of new Fox Grandeur and standard film sizes. but to look at the edge numbers which are on the side of the film and which run consecutively from the start, to determine the exact footage of the damaged film. For example, let us say that the projector has been re-threaded for five feet beyond the starting point. As we thread the projector we know that we are exactly five feet from the starting mark of the film. We now turn to the record and note upon the scale printed on the label that five feet of film requires one turn and 38 frames. With the turntable stationary, we place the needle on the starting mark. We turn the record, with the needle in the groove, one turn and around again to 37 upon the diai. We have now attained perfect synchronization with the film and we may start the projector. This can all be accomplished so quickly that the interruption is so brief as to preclude any demonstration by the audience of its feelings. As previously stated, it is very seldom that the film breaks in the middle of the reel, the bulk of trouble of this nature being encountered at the start when leader is mutilated. Film Edge Numbers All positive film is numbered along the edge consecutively and these are known as footage numbers. At every foot of film a number appears, with the numbers running consecutively to the end of the reel. Vitaphone subjects have a special numbering of their own, which may easily be distinguished from other markings. In the foregoing example where it was assumed that five feet of film had been "chewed up," suppose we should have threaded the projector at five feet and three frames. In this case we would simply add the three frames to the scale, and instead of one frame and 37 frames on the scale it would be one turn and 40 frames. Therefore, no matter what the footage, it will be simple to place the needle in the proper synchronizing point. The Footage Scale Below is printed the scale which is used for calculating the synchronization of disc and film. Previously I quoted 43.2 picture frames to one revolution of the disc, therefore we have divided the record into 43 equal parts. The .2 difference is compensated for in this scale. This scale runs up to 25 feet, but in cases beyond 25 feet it is only necessary to add the additional to the 25-foot requirements. This method is protected by Edgar J. Clarkson, patent attorney, 905 Victor Building, Washington, D. C. The scale follows : Feet Turn Disc Frames 1 16 2 32 3 1 5 4 1 21 5 1 37 6 2 10 7 2 26 8 2 42 9 3 V.. .15 10...... 3 31 11 4 4 12 4 20 13 4 36 14 5 8 15 5 24 16 5 40 17 6 13 18 6 29 19 7 2 20 7 18 21 7 ..34 22 8... 7 23 ...8 23 24 8 39 25 9 12 The operation is simple. We will repeat the procedure. First determine the amount of film that is missing. Thread the machine according to the edge number, then read the scale. Place the needle at the starting point, and with the turntable stationary, turn the record with the needle in the groove the number of turns which are indicated on the scale for that particular footage. The needle will thus be in the proper groove to insure synchronization. More on Film Patches THE following abstract from a paper prepared by Messrs. Crabtree and Ives of the Kodak Research Laboratories and read at the recent meeting of the S. M. P. E. at Toronto, is interesting in connection with the material on new film patches which appeared in these columns last month : When two pieces of motion picture film bearing photographic sound records are spliced together end to end, an irregularity in the opacity is introduced at the point of junction. This irregularity is abrupt and causes a sudden change in the light transmitted by the film passing the light sensitive element of the sound reproducing device. Therefore unless some means is utilized for gradually masking off the entire width of the sound record in the vicinity of the splice, a foreign noise is heard when this part of the record is reproduced in a theatre. One means of masking this area is by applying ink or black lacquer to the film with a brush in a triangular area covering at its widest part the splice in the sound film record. This brush work is slow and difficult to accomplish and the results obtained are often unsatisfactory. A much simpler and quicker method of rendering the required area opaque has been devised. A patch made of thin black film is cut to the desired shape and perforated on one edge similarly to motion picture film for exact registration by means of a small mounting block. With a quantity of these patches on hand, the projectionist is able to repair quickly a broken sound) record or to join two such films without introducing any noise into the record. Under the heading "Film Patches" there appeared in the November issue of The Motion Picture Projectionist a reference to a suggestion of A. Caminetsky of Brooklyn, N. Y., for a new method of sound film patching. Mr. Caminetsky recommended the use of a gummed piece of paper of exactly the same size as the usual sound film patch. This method undoubtedly would eliminate any click as the film passed the aperture ; but the objection to the method is that a paper patch is likely to peel and clog the film gate. It is apparent that the method of Messrs. Crabtree and Ives described in the foregoing will meet with the same objections as that of Mr. Caminetsky. So far as can be determined from a description of the Crabtree-Ives process there is no avoiding the; addition of an extra patch layer on top of the film. If the idea of the paper patch is rejected for fear of its peeling and clogging the gate, it seems reasonable to assume that this latest process must also be rejected for equally good reasons. Both suggestions apparently were prompted by the idea of improving sound reproduction, yet neither guarantees the , safety which is necessary with all film \ \ projection, sound or silent.