International projectionist (Jan-Dec 1955)

film with scissors, and tears extending from a sprocket hole to the edge of the film are sometimes remedied by "notching." Perforation breaks involving only one or two sprocket holes may be "notched," or smoothly cut out with scissors. When three or more perforations are damaged, it is best to cut the film and make a splice. The secret of notching film successfully is to make a smooth, rounded cutout. Poorly made notches may catch and tear on the upper guide roller, on the sprockets, or on the flanges of a reel. Certain competent authorities, in fact, condemn the practice of notching torn sprocket holes. The writer speaks only as a projectionist who occasionally notches film and has never had a film break from that cause. Most projectors which have 32-tooth feed and holdback sprockets are capable of giving good results with film from which the perforation margin has been completely removed from one side of the film. The vast majority of projectors and soundheads used in American theatres make use of 16tooth upper and lower sprockets, unfortunately. These small sprockets strain the perforations to a serious degree, especially when the reels fail to turn freely, and when small-hubbed reels are used. This danger is minimized, so far as the upper feed sprocket is concerned, by the 24-tooth feed sprockets of the Simplex X-L projector. As an alternative to either notching or splicing the film when torn perforations are found, a few projectionists go to the trouble of cementing a patch over the torn sprocket holes. The patch consists of a section of perforation margin cut from new stock from which the emulsion has been washed off. This expedient saves cutting the print, and is highly recommended for prized films from which the loss of even one or two frames would be undesirable. Weak Splices a Tough Problem Splices found in theatre-release prints are a frequent source of annoyance to the projectionist. Exchange-made splices are very good, as a rule, but they are sometimes too weak to be safely projected. Many of the defective splices are embossed with the exchange's initials or with the letters "OK." The problem of weak splices may be traced to a fear of using an adequate quantity of film cement. Film experts have often cautioned against applying too much film cement, and this advice has frightened inexperienced exchange inspectresses into using too little. Too much cement may weaken the film at the edges of the splice, but too little results in a splice which comes apart at the slightest strain. The strength of a splice in the perforation-margin area is the most important factor of all, yet many exchange-made splices have a tendency to "lift" at their ends. Too little cement applied to this region is one cause of the trouble ; inadequate scraping of the film stub is another. It is sometimes possible for the projectionist to strengthen these splices sufficiently by dabbing film cement into them and pressing them with the fingers. But no amount of film cement will make a strong splice if the stub has not been scraped enough to remove the gelatine emulsioncoating! It is admittedly possible to make strong splices by hand, but hand-made splices never pass through the projector as smoothly as a good "machinemade" splice. In a certain sense, however, all projection-room splices are "hand-made." The ordinary type of splicing block merely assists in the registration of the sprocket holes and insures the application of uniform pressure to the join while the film cement "sets." Splicing Safety Film The first and most important step in making a satisfactory film splice is the scraping of the stub. Not only must all emulsion be removed from the area of contact, but also the thin binder layer of clear gelatine. It is best to roughen slightly both contact FIG. 2. When unshrunken film is spliced to shrunken film, the resultant rough edge should be trimmed smooth. areas — the scraped stub and the base side of the butt stub. Most projectionists employ "wet scraping." The gelatine emulsioncoating is first moistened to facilitate removal, and the actual removing accomplished by scraping the stub with a razor blade. The trouble with this method is that it is difficult to get all the emulsion off in the perforation margins without tearing the film. Dry scraping with a medium grade of sandpaper gives better results if care is exercised not to scrape the stub too thin. It takes practice to know just when to stop scraping. The dry-scraping method works best when the sandpaper is backed by a small wooden block to hold it flat and insure even scraping. Small scraping blocks with the sandpaper glued to them are readily available. There is no discernible basis for the criticism that the use of sandpaper for dry-scraping film stubs leaves gritty particles which will injure projectors. Splices made by this method are wiped with a clean cloth like other splices, at once removing any dirt which may accidentally adhere to the film. Every projectionist should make "1-hole" splices, with the stubs cut straight across. The ends of the stubs should never be mitered, for the greater the contact-area in the perforation margins, the better the splice will hold. "Hairline," or negative-type, splices should not be made in release prints unless a "hot-weld" splicing machine is used. Curved splices are tabu. Cleanliness a 'Must' To repeat, single-coated opticaltrack film requires scraping of the emulsion-coated stub cut one sprocket hole beyond the frameline. The base side of the butt stub (cut on the frameline) should be wiped free from oil or, preferably, slightly roughened to insure good solvent action of the film cement. The applicator brush should be large enough to enable a liberal quantity of cement to be applied to the stub in just one stroke. No time should be lost between application of the cement and joining the stubs under firm, even pressure;. The splice is permitted at least 10 seconds, and not more than 15 seconds, for the cement to set. Then the pres (Cont'mued on page 37) INTERNATIONAL PROJECTIONIST JUNE 1955