American cinematographer (Jan-Dec 1926)

September, l!)2; AMERICAN CINEMATOGRAPHER Nineteen Cause No. 4. Too much or too strong a cement. We say "splicing" the film, when it is more correct to say "welding" the film. The cement attacks the celluloid base of the film and when the pressure is quickly applied, the two pieces of film are welded together. When too much or too strong a cement is used, the whole celluloid base is softened, instead of only the surface, causing the film to cup, or buckle, after drying. Cause No. 5. Not enough cement or cement in bad condition. If too little cement is used, it will not soften the celluloid sufficiently to make the splice hold. Film cement evaporates rapidly if left uncorked and will cause the mixture to lose its proper proportions. Cement in this condition will not hold the splice. Cause No 6. Uneven scraping. It is necessary to remove every particle of emulsion to make a good splice. (See Cause No. 3). However, great care must be taken not to thin down the culluloid base for the reason stated in Cause No. 4. Improper tools, careless handling of the film, or dirty hands will also result in poor splices. Covered hands or taped fingers will not permit the best work. So far this paper has dealt with handmade splices. Now let us examine some of the results of improperly made splices. The fact that every film passes through two or three different makes of projectors, and that each of the three most widely used make threads differently from the others, it does not make any difference whether the splice is lapped left or right. Bad Splices Certain tests show conclusively that the film invariably runs off at the take-up sprocket, and ninety-nine times out of a hundred the run off is caused by a bad splice. The reason for this is that the film at the top sprocket is kept taut by the tension on the reel in the top magazine, and the film is kept taut at the intermittent by the tension at the aperture. The film feeds on to the bottom sprocket out of a loop that is constantly slapping back and forth, and a slight imperfection in a splice will cause the film to run off and become damaged. Not only has a great deal of damage resulted from improperly made splices, but oftimes the presentation of a picture is greatly marred. A bad splice also constitutes a fire GOERZ Negative Raw Stock — more definition — no grain — also in special daylight loading spools for BELL & HOWELL "EYEMO" CAMERAS and other cameras using 100-foot spools. IS Sole Distributors: Fish -Schur man Corporation 45 West 45th St., New York 1050 Cahuenga Avenue, Hollywood, Calif. IN CANADA: John A. Chantler & Co. 200 Bay Street, Toronto, Ont. BRUSSELS VIENNA ROME MADRID LISBON JERUSALEM LONDON RENE GUISSART Atmospheric Shots in Any Part of Europe Taken according to your own instruflwns in an artistic manner to match the phography of your produrllon. OFFICIAL CORRESPONDENT IN EUROPE FOR: American Society oj Cinematographers ; Frank D. Williams 118 Avenue des Champs-Elysees PARIS Cable Address: LOUVERANDE-PARIS BERLIN BUDAPEST GENEVA CAIRO ATHENS ALGIERS ETC. ■TC.