Movie Makers (Jan-Dec 1949)

338 SIMPLE recording setup, using ready sound kit, can be varied left to right as is convenient. FIRST mirror is clamped to upper right corner of screen when recorder is placed right of projector. CONTROLLING SOUND ON WIRE AUSTIN D. JOHNSON IN the April issue of Movie Makers there appeared, on page 135, the stimulating and helpful discussion by Warren A. Levett, ACL, entitled Synchronizing Sound On Wire. In it he outlined his method of using the intermittent flicker of the projector's light beam in reaction with a specially designed stroboscopic disc, which had been positioned on the takeup spool of a Webster wire recorder. With this arrangement it was then possible to adjust the speed of the projector, if and when needed, to hold it in step with the more constant speed of the magnetic wire playback. HANDY SOUND KIT There has been — as readers of this magazine will know — a great deal of interest in Mr. Levett's ingenious and effective system of magnetic sound control. It is because of this that I venture to bring to the attention of Movie Makers readers a handy accessory for this operation which I recently ran across. Put out by Sears, Roebuck & Company, the outfit is known as the Silvertone home movie sound kit. The essential parts of the kit, as far as sound synchronization is concerned, are two small mirrors and two stroboscopic discs of varying pattern. Also included are four doublefaced 12 inch Vinyl records carrying some 52 different sound effects for use on one's magnetic track. FITS MANY RECORDERS The kit was designed, I understand, primarily for use with the Silvertone wire recorder. It can be used equally well, however, with any magnetic unit passing wire at two feet per second. This, of course, includes such well known models using the crescent mechanism as the Webster (used by Mr. Levett j, the Majestic and the Airking — to name a few which come to mind. In operation the kit functions as follows. One of the mirrors Cthe one with the clamp) is attached at any convenient point to the frame of one's screen — say at the upper right corner. The other mirror (which has a screw mounting) is then positioned on one's recorder so that it can reflect light onto the takeup spool or turntable. One or the other of the strobe discs is then placed in position on the spool or turntable. DISCS FOR ANY PROJECTOR The reason for having two discs of varying pattern is found in the projector one is using. As Mr. Levett already mentioned, the light pulsations coming from a projector depend on the number of times the shutter interrupts the light path in projecting a single frame. Since this varies in projector design from one to four flashes per frame, the two different discs are necessary. It will be found by simple experiment which one of them functions properly with your machine. With the correct disc in place, the two mirrors are then adjusted so that they project onto the disc the strongest possible reflection of the projector's pulsing light. It is this light, of course, which reacts on the disc to supply the same control of projector speed as was achieved in Mr. Levett's setup. SYSTEM IS FLEXIBLE It has occurred to me, however, that the system offered by this sound kit may provide slightly greater flexibility of operation than is possible in the other arrangement. It may be recalled that in Mr. Levett's setup the pulsing light of the projector was cast on the strobe disc by positioning the Webster recorder directly in front of the projector and just below the light path. In this way, to be sure, enough illumination from the beam fell on the strobe disc to provide the control desired. But at the same time, the system does require a fixed positioning of the recorder in relation to the projector. With the use of the two mirrors, this single possible setup is done away with. I have suggested earlier that the mirror clamped to the screen be placed at the upper right corner. This, I think, would be the most efficient arrangement if one wanted the projector at his left side and the recorder at his right. On the other hand, if the projector speed control happens to be on the left side of the machine (as it was,