Motion Picture News (Nov-Dec 1918)

November 2 , 1 p 1 8 (Equipment Service) 2783 Devoted to the technical branches of the motion picture industry, containing records of the latest accomplishments in the mechanical and scientific field; projection helps, inventions and suggestions; camera devices analyzed and commented upon; musical cue sheets for important feature pictures; improvements and innovations in the building and furnishing field. No charge is made in these departments for answering questions of any nature. Correspondence is invited. E. Kenball Gilleti — Editor Alfred S. Cory Technical Editor Facts for the Operator THESE facts have been taken up separately before in these pages but have never before been put together. The only section on which we wish to comment is the Fourth. In this we would suggest that the greatest care be used in the selection of a cleaner, as there is nothing worse than the pad type, which collects grease, dirt and grit, and after having a reel or two run through becomes about as useful for cleaning film as a piece of emery paper would be. Therefore the type of cleaner selected must be chosen with the greatest care and watched continually. Suggestions for the Conservation of Film and Moving Picture Machines It is a fact not generally known that valuable film is injured and its life much shortened by improper methods of operation in handling and projecting the film after it has been delivered by the producer and film distributor to the exhibitor, and the following points are worthy of your consideration : First — When a film is new and has not been specially treated, such as the ordinary positives are when delivered to the exhibitor in the majority of cases, the stock is what we call "green." In explanation of this, it may be stated that the emulsion on a new film, while being dry, is still in a semi-plastic state. Due to this fact, when such film is run through a projector or moving picture machine, the emulsion retards the film movement, and particles of the emulsion arc deposited upon the sprockets and upon the film tension shoes, as well as upon the aperture runners. This deposit welds itself in spots upon the above mentioned parts, causing an enormous increase in friction, which must be overcome by increasing the power applied for driving the machine so as to maintain proper projection speed. The increase in power applied puts additional strain upon all parts of the moving picture machine, and at the same time necessarily puts additional strain upon the sprocket holes, which are being engaged by the teeth upon the sprockets of the projector. This strain, in some instances, elongates the sprocket holes, which, on subsequent runs of the film, impairs the steadiness of the projection and has a serious effect upon the life of the film. To overcome this condition, processes are available for hardening or treating the " green " film surface, which in a great measure relieve the friction. Another method which may be recommended to overcome the friction incident to the use of " green " film is to apply a set of small wicks feeding special lubrication to the edges of the film which come in contact with the sprocket teeth and the guides in the projector while the film is being projected. This method has been applied with much success in some of the film censorship exhibition rooms, but when this method of lubrication is used, it is, of course, necessary, or at least advisable, to run the film through a film cleaner before it is put back on the reel and returned to the exchange, so as to remove any lubricant remaining upon the emulsion. It is safe to estimate that 20 per cent, of the wear on the film, and upon the machine, takes place during the first few runs with " green " film. Second — The greatest abuse to, and wear upon, films, whether new or old, and to moving picture machines, takes place when over-speeding the machine. This practice is the cause of more film and machine trouble, and introduces more waste, than any other fault in the projection of films. The normal speed of a thousand feet of film is from twelve to fifteen minutes, but we know of theatres projecting the same length of film in from six to ten minutes, so as to enable a greater number of exhibitions within a specified time. The strain upon the mechanism of the projector is more than doubled by such increase of speed, and the strain upon the sprocket holes and the film splices is comparatively enormous, and it is a wonder that the projector and the film will last as long as they do. It is safe to estimate that more injury is done to a film operating above normal speed ten times through a projector, than when the same film is operated through the same projector one hundred times at normal speed, and this also applies to the wear upon the projector. Another serious consequence of excessive speed follows the opening of a splice, or the breaking of the film, because, at high speed, the machine cannot be stopped instantly and, therefore, large lengths of film may be chewed up and destroyed before the projector can be stopped. Third — The general use of a small film splicing device costing from five to fifteen dollars will enable every operator of a projector to make perfect film splices, which is absolutely necessary to the proper operation and conservation of film. Fourth — Every theatre should be equipped with an approved type of film cleaning device. Such devices are very simple and cost less than ten dollars to install, and the cost is less than one penny for each thousand feet of film cleaned. It is not necessary to clean the film each time it goes through the machine, but the film should be cleaned at least once while it is in possession of a theatre, and preferably just before the last run, so that there will be a minimum amount of dust and carbon deposited upon the film when it is returned. Fifth — The writer has observed a lack of unity in the length of film titles and announcements of reading matter. A good many feet of film can be conserved by standardizing the length of the titles upon a uniform basis, depending upon the number of letters or words exhibited. This brings us back to over-speeding, and it is well to remember that, if a film title is prepared for proper projection speed, the same title must be twice as long when over-speeded 100 per cent. Sixth — Much film damage is done by improperly designed and constructed machines, and also by standard machines of recognized high quality, when not kept in proper adjustment and repair. Under this heading the following points should be considered : (A) If the take-up which winds the used film .upon the receiving reel is not properly designed or adjusted and if the tension sWould be too tight, or if reels with too small hubs are used, it is possible for the take-up tension to strain the film so that the lower sprocket will almost cut through the stock between the perforations ; even a slightly excessive take-up tension will elongate the perforations and injure the film. Operators should be warned on this point. (B) A machine with a worn intermittent sprocket may destroy a perfect film by running it through only once. (C) Worn aperture plates and excessive tension on the film guides, or shoes, will seriously increase the friction, with consequent damage to the film. (D) Worn idlers, rough stripper plates, and too long or too short loops may ruin a perfectly good film operating through the machine only once. (Continued on page 27%)