The Cine Technician (1943 - 1945)

40 THE CINE-TECHNICIAN March— April, 19-43 THE SUB-STANDARD SOUND FILM Describing a method of printing 35 mm. sound on 16 mm. film without reduction, and its attendant advantages. By T. USSHER SMITH TO understand this article thoroughly it is necessary to revert to the introduction of sound attached to moving pictures. The 35 mm. silent him traversed the projector at a speed of one foot (i.e., 16 frames) per second. A sound track was then attached to one edge. This was the first talking picture of the present type, but it was found that although at this speed perfect animation was obtained, the sound was very poor. The speed was then increased to eighteen inches per second (i.e., 24 frames) which resulted in a commercial reproduction. This is the standard tuda\ . With a knowledge of the above facts, the great and powerful organisations of the Film Industry in Germany, U.S.A. and Great Britain have expended enormous sums of money in research to obtain 35 mm. results by attaching a sound track to a sub-standard film which can only provide a sound track space for a traversing speed of 7 inches (i.e., 24 frames) per second. This is the present situation of the 16 nun. film with the attendant poor results and the sacrificing of perforations on one side of the film. An entirely new system of 16 mm. sound film has recently been demonstrated in a small but efficiently equipped laboratory in the centre of London. This system provides a film of 16 mm. to be printed with a 35 mm. track in contact in the orthodox manner, and the track to be traversed at 35 mm. speed, although the picture is projected at 16 mm. speed. I have seen and heard an ordinary 16 mm. print projected in comparison (same amplifier) with one from the same negative printed in the new style, and the difference in quality is truly astounding. There are several other advantages such as central traction, no re-winding, fool-proof threading of projector and longer life of the finished product. The film is 16 mm. wide — 3 mm. either side is provided for a standard sound track. The perforations are the same dimensions and pitch as on 85 mm. film, and are positioned so that tlie first two are side by side, with the outer edges touching the inner edge of the sound track space, and 8 mm. down in the centre is a single perforation of the same dimension. The sequem of perforations thus visually appears as on a No. 5 domino. The result is that spaces 8 mm. x 1" mm. in between these perforations are provided to receive the picture images. These mute images are, of course, printed by optical reduction in the usual manner, except that the intermittent mechanism displaces three-quarters of an inch of unexposed positive as in standard 85 nun. practice, which is the equivalent of 2 frai of 16 mm. picture. The mask in the 16 mm. gate allows only one of the frames to be printed and results in an alternate image and space all through the reel. When the reel is complete it is taken off and placed in position without re-winding for a second set of images to be printed in the blank spaces. The fact that it is not re-wound, reverses it from side to side and upside down; the intermittent engaging with the two perforations which are always at the top of the picture prevents overprinting and forms a finished print with the images upside-down to each other. I now come to the printing of the Sound Track. It will be understood by the above description that each frame is provided with three-quarters of an inch in length on either side of the sound track, and is progressing at the 35 mm. speed. The sound for the first run is on the one edge, and on the other edge the sound for the second run, which automatically takes its proper position over the Photo Electric Cell as it is never re-wound. The usual form of track printer is used, excepting that the gate sprocket is designed with an extension on one end to accommodate the 16 mm. film. The Standard teeth are left on the outer edge to engage on the 35 mm. negative, and two out of every four of the teeth on the opposite edge are removed, as the perforations on the 16 mm. are the same size and pitch, and the sound track on the 35 mm. being inside the perforations the space left on the 16 mm. will overlap in its propel position to receive the track print in the usual manner. Reviewing the above, what advantages does this system have over the present ? 1. Sound identical in every maimer to 35 mm. 2. Perforations providing central traction, thereby making the life of the prints equal to that of 35 mm. and thus allowing a much lower commercial Library charge. 3. Re-winding (which causes wear on films) is considerably reduced. 4. Fool-proof in use. ."). \n\ oo nun. projector can be modified to project this film.