Moving Picture World (July-Dec 1909)

220 THE MOVING PICTURE WORLD or tinted film, though even this may sometimes be saved by prompt action. But the unrolling must be done verj quickly. When it is desired for any reason to remove the emulsion a film it may be done by soaking in warm water to which has been added sal soda (common washing soda will do). Use plenty of the soda and let the film soak for say 15 minutes, and you can then wash the emulsion off easily. It may I" removed by soaking in ordinary cold water and then scraping. Proceed as follows: Soak the film until emulsion 1 soft. Lay film, emulsion side up, on a flat board or table and draw it under the blade of a knife. If the knife blade is long enough and the edge straight enough the whole surface of the film will be cleaned at one "swipe." Film should, so far as possible, be kept in a cool, moist place, though the matter of moisture may be overdone. If you get too much of it the emulsion will stick to the pack of the film. It is a mere waste of breath telling operators not to keep spare film near the ceiling of a hot operating room. They will keep it where it is most convenient. However, films not on the machine should be kept in a solderless metal box or cabinet • located near the floor, and if fastened to the wall it should be so attached that it may be instantly lifted away and carried outside in case of fire. Where a film tank is used it is well to have the bottom covered with a coarse screen held an inch from the bottom by wo,, den or metal cleats. In the bottom of the tank keep some water to which has been added just a little glycerine — one part of glycerine to 33 of water is about right. This will be very beneficial to the films. Old, brittle film may be made pliable as follows: Get any metal can large enough to hold a film when unrolled loosely. The can must have a tight cover. Cover the bottom with a coarse screen, leaving an inch or two below it. Into this space place a mixture of water and glycerine as above. Unroll the film into the can and leave it in a moderately warm room for from one hour to half a day, according to condition of film. Examine it frequently. Don't leave long enough \lo soften the emulsion too much. Another way is to give the film a bath in the aforenamed solution. To do this build a drum by nailing lattice lath around a couple of barrel heads. Place the solution in a washtub or other suitable receptacle and immerse the film in it, winding immediately on the drum with emulsion side out. The drum should be geared so as to run tast enough to throw off all surplus liquid. Be very careful in handling the film after it is wet, as the emulsion is then soft and the least scratch will play havoc with it. This operation must be done in a room where there is no dust. Snrinkle the floor well before commencing. It will perhaps be best for the novice to place the liquid in a long, shallow pan. merely drawjng the film slowly through the mixture as it is wound onto the drum. The drum must be revolved until the film is dry. Glycerine absorbs moisture rapidly and that is the 'reason it is beneficial to a film. Don't use more than one part to 33 of water, however. When yon have an old film with a short title, put on a good, long leader, attaching so it is in frame with the title. Frame ni) on the leader and when the title comes it will have to be very short if the audience cannot catch it, provided you run slowly. Right here let me caution you to always start your machine slowly. If you start fast and have to frame on the title it is gone before there is any chance to read it. especially if it be a short one. When the operator has the opportunity he should invariably inspect his film before running it the first time, cementing all loose patches and making any other needed repairs. An ounce of prevention in this respect is worth several hundredweight of cure. The inspection given films in some exchanges is very largely a matter of vivid imagination. If the film isn't clear in two somewhere it is enthusiastically O. Ked by the inspector, who is expected to "inspect'' (???) a thousand feet of film in ten minutes or less. I know I am roasting the exchanges a good deal, but unfortunately it is all "coming to them" — or to some of them, rather. Those the shoe doesn't fit need not wear it. In looking over film unwind into the tank or takeup and rewind slowly, holding film by edges with pressure enough to "cup" it. You will thus by sense of touch be able to detect all broken sprocket holes and loose patches. If more than two sprocket holes are missing in one place, cut it out. In case you should ever get caught without cement, an emergency substitute may be had in ordinary liquid glue. Proceed as you would with cement, but use the glue instead. Don't put much on. though. and give it ample time to dry. This should only be done in case of emergency, however, as it is by no manner of means good practice and makes but a very, very poor job at best. You can measure the exact length of a film by runnine it through a machine, counting the turns of the crank. The Power's. Edison, Motiograph, and, I believe, the Lubin, also, nass exactly one foot of film to each turn of the crank. The Viascope passes nine inches. And now let me call your attention to the fact that, at a normal speed of 60 feet per minute, 960 separate and distinct photographs must stop dead still — dead still, without a quiver or particle of vibration, each occupying precisely, to the thousandth of an inch, the exact space filled b\ its predecessors — each minute. It requires slight discernment to see that to accomplish a result so marusly rapid and accurate not only the mechanism, but the film itself, must be in good condition. The writer has had hundreds of letters asking why some new films apparently sway sidewise with rhythmical motion and others continually jump on the screen. The first named fault, usually attributed to lost motion in the camera, is due to the use of a rotary perforator. The last named fault lies in the perforation also. It would occupy much valuable space to enter into detailed explanation as to the exact why and wherefore and could accomplish no corresponding good. Old, dry films jump because (a) the sprocket holes are shrunken, (b) sprocket holes are worn. The first named fault may be remedied by moistening the film as before set forth. Films will jump more or less when run on a machine with worn intermittent sprocket teeth or wdiere the star movement is too loose; also, they will jump badly when run on a finger feed machine the fingers of which are worn. The film gradually cuts a little groove in the fingers on the under side. It is hardly discernible until they are taken out and closely examined, but the effect is there just the same. Remember that with a fifteen foot picture a jump of 1-1000 of an inch becomes 180-1000 on the curtain, while 1-64 inch would become almost three inches. In other words, a fifteen foot picture magnifies the film photo 180 times its diameter, and it follows that any defect is magnified that many times also. From this you may see how absolutely accurate must be the perforation of a film to secure an absolutely steady picture. The marvel is that old films run as well as they do, the more especially when run on a worn machine. In closing this subject, I believe it well to give a very brief, crude description of the way a motion picture film is made. Celluloid is a composition of pyroxylin and camphor, the latter being nothing more or less than ordinary cotton which has, by a bath of nitric and sulphuric acids mixed in nearly equal proportions, been converted into gun-cotton. But it must not be inferred from this that celluloid is in any degree whatever explosive, for it is not. A certain mixture of pyroxylin and camphor, dissolved, or partially so, in alcohol or ether, produces the crude celluloid, which may appear as lumps in the bottom of the acid tanks or in blocks in a press, according to detail of manufacture. The crude celluloid is worked by cold and then by hot steel rolls and is then subjected to prolonged, heavy pressure, after which it is dried in kilns for several days. It is now in the form of cakes, which are worked into strips 200 feet long by 22 inches wide. A machine next coats this strip with the photographic emulsion by passing it beneath a hopper filled with emulsion, in the bottom of which is a narrow slit. Another machine now splits the 22-inch strip into ribbons \Y% inches wide, which are then ready for sale to the film photographers, or film makers, as distinguished from film stock makers. The film stock maker only perforates such stock as is ordered perforated, since film makers usually do their own perforating. The perforating is done by a punch press, of which there are several kinds. Some are rotary, some punch two, one hole on each side, and some punch four at a time. There are exactly four perforations to each % inch of film. The film is fed to the press by an intermittent movement or by a pawd and ratchet. Negative films (the ones the photographs are taken on) have a much "faster" emulsion than have the positives. Such is a rough sketch of the process of manufacture of motion picture films, and one has but to glance at the constituent parts of celluloid to understand why it is so inflammable, just what changes in manufacture are brought about by the new non-inflammable film the writer does not know. All he knows about it at this time is that a different cement is required for it than was used for the old stock. Bellevue, Ohio. — W. J. Frv has sold the Theatorium Motion Picture Show to Willis Dewalt. of Tiffin. The National Waterproof Film Company, 21 15 West Adams street. Chicago, send us a sample piece of film which has oeen treated by their process. After putting it to the most severe test we can only say that the emulsion side of the film is rendered absolutely proof against water, either cold or warm, and the enamelin" also serves as a protection against scratches. The ease with which film may be cleaned, the freedom with which it may be handled and the extended time of its usefulness in good condition are features which should commend this process to the attention of all film exchanges.