Motion Picture News (Nov-Dec 1917)

3224 ACCESSORY NEWS SECTION Vol 16. No. 15 ^iiiii'iiiiiiiiiiiiiiiiiiiiiiw iii.'iii!»i:!Mi:riii!'i!iKiw!iiiiniiiiw ^.iimnHniiiatiiiiHiawiiiimBi-i!:;-!';;'!!!;-!'!; i.:. .;..:imaiiiainaiimiHaiHJHi{i mmmummm EQUIPMENT OPERATING PROJECTION QUESTIONA N S WERED ■l large percentage of the operator's troubles are due to the bad condition of film, and it is also an established fact that a new film deteriorates rapidly with use. Mishandling; worn or incorrectly adjusted projector mechanisms; and a variety of other causes contribute to this rapid deterioration of a film positive, but it can be emphasized that a film positive, carefully prepared in the laboratory, and used by a competent operator on a clean and accurately adjusted projecting machine, may be screened thousands of times without showing any appreciable effects from such use. This is not an imaginative statement formulated as an introduction for that which follows, but is founded on the study of the condition and characteristics of many reels of film which have undergone long and continuous use under our personal observation. The proper care of motion picture positive prints is a subject of itself, but we propose on the present occasion to record some observations on the important item of the splices by which lengths of cine film are joined together. Film splices are termed " patches " by the average operator, but this term is rather a misnomer, and is discouraged by makers of cinemachinery, while the term " patch " is rarely heard in a film laboratory. Modern positive printing methods have made possible the preparation of a thousand-foot reel of film with as few as five or six splices for a straight black and white subject, but in the case of a film containing frequently alternating scenes of different tints, a reel as issued by the laboratory may contain a great manyjoins. Although a new film positive is supposed to be in perfect condition, it is a fact that there is much careless joining done in cinematographic laboratories, and it seems that every film joiner in a laboratory has his, or her, own special method of The Mechanics of Film Splicing and a Suggested Standard Film Join making a splice. The technique of splicing, such as the scraping of the emulsion from the film, application of the cement, etc, has been frequently dwelt upon and need not therefore be considered here. One point should be established, however, before we proceed further; it is not possible to make a perfect, or even a highly serviceable, splice in cine film without the aid of a splicing machine (so called) or press, wherewith to force the cemented edges of the film into complete contact at the point where the join is made. In that which follows the use of a press of some sort is assumed, since it is indispensable to the production of first-class results. There are a variety of methods of cutting and overlapping the ends of two pieces of cine film in order to make a join, but they are all derived from two distinct and extensively used types of film splice. As no good could come from the description of numerous impractical types of join, we shall therefore consider only the two principal forms, and it will presently be apparent that one of these types of join is so vastly superior to the other that there is, in fact, only one type of film splice which is worthy of consideration and use by the laboratory and the conscientious operator. Fig. 5. In Fig. 1 is shown a type of film join which is in extensive use. As Fig. 1 shows, this style of splice is made by cutting the two ends of the film to be joined right through the middle of the space between two consecutive pairs of sprocket holes. The section A of the film then has the emulsion scraped away to the center of the space between the two pairs of sprocket holes nearest the end. The end of film B is then laid over it ; the sprocket holes registered; and the join made. In spite of the fact that this type of splice is in extensive use it can be stated that a large percentage of cases of losing the loop, film riding the sprocket, and other accidents while the film is passing through the projector are due to this impractical and unscientific type of film splice. A splice of this type also makes more noise when passing over the intermittent sprocket than most other forms of film splice, and while it might be thought that this is an inconsequential item, the fact that such splices make a lot of noise in traversing the intermittent is an indication of itself that they are not passing through in a frictionless and unimpeded manner. The result of this is severe wear on the film, and the rapid breaking down of the sprocket holes following a join of the type in question. The appearance of these broken sprocket holes is shown in Fig. 2, which is based on the study of films, otherwise in perfect condition, which have been repeatedly projected on a machine which was in first class adjustment. Fig. 2 refers to the effect of a splice such as is depicted in Fig. 1 on the pairs of sprocket holes following the splice. Needless to say, this breaking down of the sprocket holes, when once started, spreads rapidly along the film. The reason for this will be presently explained, but a further study of Fig. 1 will make it plainly apparent that to make a join which encircles the sprocket hole is to join the film at its weakest point. Let us, however, see why it is that the form of join illustrated by Fig. 1 is handled so roughly in its passage through the projector mechanism. The reason is really a simple case of mechanical misfit, as is made evident by Fig. 3. In Fig. 3 is shown a section of a projector sprocket. A join of the type represented