Moving Picture World (Nov - Dec 1918)

604 THE MOVING PICTURE WORLD November 2, 1918 HOW TO CONSERVE FILM AND MACHINE Vice-President of United Theatre Equipment Advises Exhibitors on Vital Trade Problems By J. H. HALLBERG. Tlu normal speed of a thousand feet ii 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. It is a wonder the projector and the film 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. Film Splicing Device Essential. 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 a perfect film splice, 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 $10 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, 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 overspeeding, 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 overspeeded 100 per cent. As to Importance of Repairs. 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 point 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 should 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 IT is a fact not generally known that valuable film is injured and its life much shortened by improper method 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 operated through a projector or moving picture machine, the emulsion retards the film movement and particles of the emulsion are 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. Strain Elongates Sprocket Holes. 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 relieves the friction. Another method which may be recommended to overcome the friction incident to the use of "green" film isto 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, ourse, 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. First Runs Hard on Film. Tt is safe to estimate that 20 per cent, of the wear on the film and upon the machine takes place during the first few run with "green" film. Second. The greatest abuse to and wear upon films, whether new or old, and to moving picture machines takes place when overspeeding the machine. This practice is. in the writer's opinion. . ause of more film and machine ,1,1c and introduces more waste than other fault in the projection of films. 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. (e) The use of damaged reels with sharp edges and which do not run true should not be permitted, as they are the means of much film destruction. Use Judgment in Lubricating. (f) The lubrication of moving picture machines should be moderate so that a minimum amount of oil will deposit upon the film. In fact, a machine properly lubricated and cleaned will not deposit oil or dust upon the film. (g) In many machines in service the fire-trap rollers on the magazines are either worn out, rough or stuck, due to lack of attention, allowing the delicate emulsion of the film to drag along this surface at a high rate of speed, injuring the film. (h) In a properly designed, constructed, adjusted and operated projector a film is practically absolutely safe from fire; but when the film splices are poorly made or when the machine is not properly adjusted and in proper repair, as above referred to, the hazard from fire, with consequent destruction of part or the whole of the film, is likely to follow. A film fire not only ruins a part or the whole of the film, -but it also destroys a considerable part of the projector. Therefore it is reasonable to assume that great conservation in both films and machines can be effected by the very ordinary means suggested above. Seventh. An observer in the operating or rewinding room of a theatre will in many instances find, that the method of rewinding a film can do much injury to the emulsion. A continuous steady speed with uniform tension packs the film gently and nicely upon the reel, whereas jerky action and overspeeding in rewinding is likely to do much damage. In the ordinary theatres rewinding is done by hand, and can be done well and properly with little care, but in the more modern theatres rewinding is now done within fireproof inclosures automatically under uniform tension and speed by electric motor drive, which method should be recommended wherever possible, as it not only saves the film, but it also conserves man-power, as in many instances extra labor is employed in rewinding. The better informed operater understands and realizes the importance of the foregoing, which is also well known to the maker and distributor of the film. Eighth. Conservation of carbon electrodes, arc lamps, lamp houses, condensing lenses, asbestos covered copper cable and copper lugs : Conserving Carbon. The conservation of carbon electrodes as used in projector lamps with the electric arc can be effected by using what is known as "carbon savers," which