A-B-C of Motion Pictures by Robert E. Welsh

The average amateur photographer, who has made a practice of developing and printing his own photographs, will find little of interest in a description of the stages through which the film passes in a motion-picture factory. It is essentially the same process that he follows, though, naturally, on a much larger scale and making use of all the mechanical appliances possible. The variations in the chemical formulas used are those which the studious amateur's own judgment would dictate to him were he working under conditions similar to those of the motion-picture photographer.

His day's work completed, the camera-man takes his negative film, which is contained in the take-up box of the camera to protect it from the light, to the factory. The film taken from the camera now faces the following steps: the development, washing, and, finally, fixing, thus producing a "negative" from which the "positive" prints used for exhibition purposes are to be made. The development of the negative takes place, of course, in a "dark room," that is, dark in the photographic sense, the sole illumination being that of lamps providing a pure red light. The negative strips are wound spirally about pins on a rectangular rack, thus making it possible to wet the entire surface of the film simultaneously and equally when the rack is submerged in the developing solution.