Page:Popular Science Monthly Volume 90.djvu/850

 How Motion Picture Films Are Made

By R. W. Baremore

���On these big drums the films are dried after developing. They revolve slowly, throw- ing off the water and exposing the emulsion side to a constant current of hot air

��THE system of taking a motion picture and the developing and printing of the film, follow closely the methods employed by the amateur photographer, even though the film is handled in very much greater lengths. It is run through the motion picture camera in much the same manner as in the lowest priced kodak; it is developed in a tank similar to the amateur's, although many times larger, and prints are made from the negative in the well-known way, ex- cept that the positive is printed on a cel- luloid film instead of on sensitized paper.

As a general rule motion pictures are made in thousand- foot lengths. The reg- ulation camera and pro- jection machine holds this length of film. What are known as "features" are produced in multiple

���The developing room. The work- man is agitating the films in a bath

��reels. Hence the familiar sign "Mary Pickford in Three Reels." This, we know, does not mean that Little Mary has been cut to pieces but that it was necessary to utilize three thousand feet of film to produce the picture.

Motion picture film is much more dur- able than that which is used in the kodak, and the emulsion is considerably faster. The film is one and three-eighths es in width and is made n two-hundred-foot lengths, the full reel or one thousand feet being secured by cementing five of these lengths to- gether. On both outer edges of the film are perforations averaging sixty-four holes to the foot. These must be made with great care so that the picture synchronizes with the projector shutter. When the cameraman

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