American cinematographer (Jan-Oct 1925)

Four AMERICAN CINEMATOORAPHER December, 1925 PROJECTION * Conducted by Earl J. Denison Splicing of Film Requires Qreat Care ( This paper was presented before the recent meeting of the Society of Motion Picture Engineers.) During the past ten years the mechanical processes involved in the making of motion pictures have — for the most part — been subjected to critical analyses followed by changes and improvements which have resulted in increased efficiency. Processes of major importance—the perfection of the film; the taking of the pictures; and the making of positive prints — are now carried on by means of standardized machines and instruments, the use of which insures surpassingly fine artistic effects joined with a minimum of production cost. Scant Attention But some minor processes are of major importance and these have received scant attention. The splicing of film is a case in point. This process has — until recently — been carried on by crude methods which have produced unsatisfactory results. A faulty splice may throw the picture out of frame, trespass upon the picture space, stiffen the film at point of splice, or give way altogether. And to the extent that it does any of these things it makes impossible the production of the perfect motion picture. A more intimate knowledge of motion picture film, the use it is subjected to in the theatres, together with the science and reasons for .prop er inspection, splicing and handling will lead those engaged in this particular branch of the industry to an understanding and appreciation of the necessity for perfect work. Perfection Of primary importance among the mechanical processes is that of film perforation, as accuracy in this operation is the first: requisite in the making of quality pictures; i. e., being the initial operation, successful handling of the succeeding processes is only possible with the utmost accuracy in film perforation. The fact that the life of the film depends almost entirely on the physical and mechanical conditions of the perforations ( Sprocket Holes) proves that the utmost care should be exercised to prevent the perforations from becoming damaged. The matter of splices has never been confined to any one locality, but constitutes a problem for all laboratories, exchanges and tne theatres. This problem presents features more complicated than the mere holding quality of the splice, and the recurrence of complaints shows clearly that a satisfactory means of splicing film to withstand the use to which the prints are subjected in the theatres has yet to be standardized. There is very little difference in uniformity, flatness, register, etc. It is an easy Careless Workmanship Brings Heavy Loss to Theatre and Producer matter to obtain strength, but strength alone does not constitute a satisfactory splice. Ultimate Test Projection is the ultimate test for the mechanical and physical qualities of the splice, as well as the film, and while practically all film damage occurs in the theatres, about 50rf of the damage is traceable to improperly made splices for which there are six primary causes. Cause No. 1. Splice out of register (of sprocket holes not perfectly matched.) Splices of this kind will jump while passing through the projector and probably damage the film. Cause No. 2. Splices too wide. A splice is stiff and unbending, and if too wide will not seat properly on the sprocket wheels of the projector, causing a jump with probably damage. Cause No. 3. Emulsion or gelatin not entirely removed. Due to the fact that film cement only acts upon the celluloid base of the film, it is necessary to entirely remove the emulsion in making the splice. Where there is a particle of emulsion, the cement will not hold, causing the splice to open and come apart. Cause No. 4. Too much or too strong a cement. We say ''splicing" the film, when it is more nearly correct to say ''welding" the film. The cement attacks the celluloid base of the film and when the (Continued on Page 16)