Photography self taught

From an economic standpoint the motion picture business, including the manufacture of film and other materials, and the production and showing of pictures, is one of the major industries of the country.

In the past, entertainment has been the primary aim of motion pictures. Now the field is broadening until it seems likely that their greatest contribution to mankind will be in science, in industry, and in education. Especially in research work are they valuable as cameras have been devised that will take from 500 to 4000 pictures a second of such subjects as a bullet piercing armor plate, a bird in flight, mechanical motion, chemical action, or rapidly moving microscopic life. The pictures can then be printed individually or can be projected as slow motion pictures at only a fraction of the speed at which they were taken, so the subject will seem to barely move. By analyzing motion many extremely important facts have been learned. In industry such pictures may be used to show where lost motion can be eliminated and how an operation can be performed more efficiently. When it comes to athletic sports, it is very difficult for the individual in football, tennis or crew to realize just where his weakness lies, and what he lacks in form, but when he sees himself on the screen as he actually performs each individual movement, he can improve himself accordingly.

As it is generally recognized that knowledge is more quickly gained by the visual method than in any other way, schools, colleges and universities are using motion pictures more and more as an aid in teaching all kinds of subjects. Often there is no sharp line between educational and entertainment films. Dramatic films may be found useful for art classes; science and travel films in the study of such subjects as physical geography, geography and history. Films showing such interesting phases of nature study as micro-organisms, the life history of the bee, and the emerging of the butterfly are invaluable in teaching biology and its allied sciences. Even in the lower grades, animated drawings and maps and other types of pictures find their places.

PRINCIPLE OF MOTION PICTURES

Motion picture cameras are arranged to take long rolls of film, often several hundred feet in length. Standard film is 35 mm. (1⅜ inches) wide. By turning a crank at a uniform rate of two revolutions a second, the film is carried past the lens and eight exposures are made at each revolution, or 16 a second, which uses about one foot of film. A revolving shutter admits light to the film which stops during the exposure. Each picture is made in ¹/₁₆ of a second and during this time the shutter must open and close and a new section of film be drawn down for the next exposure.

The film is developed, fixed, washed and dried and then printed on positive film which in turn must be developed, fixed, washed, dried and perhaps tinted.

The motion picture as seen on the screen is really a series or still pictures projected at the rate of 16 a second. Each picture is on the screen but a fraction of a second, the film not moving during this instant. Then the rotating shutter covers the lens in the same way as when the picture was being taken while a new view is brought down into position. During the time between pictures, the screen is perfectly dark, but because of “persistence of vision,” this is unnoticed so that to the audience the projected still pictures make up the regular motion picture with which they are familiar.

PICTURES IN THE HOME

The desire for making personal motion pictures is a very common one. So irresistible is this appeal that almost everyone has long wished for movies of the people who particularly interest them, movies that they could make themselves and then show in their own homes. But until recently there have been outstanding obstacles. Ordinary film is so inflammable that many states have laws against its projection except in fireproof booths. This often makes it impossible to show pictures in a small school, church, or home. Also, standard film, which is taken at the rate of 1 foot a second and then has to be printed on an equal amount of positive film, makes the process expensive for those who wish to make their own moving pictures.

To overcome these disadvantages simple motion picture cameras such as the Ciné-Kodak (Figure 9) are now made which use only a narrow width safety film, 16 mm. (⅝ inch) wide. Some are operated by a crank the same as professional cameras; others by a spring motor. With the type using a motor, the camera can be held in the hands when the picture is being taken.

Four hundred feet of this film gives the same period of projection when used in the Kodascope (Figure 10) as a thousand feet of ordinary standard film, and as the film which is sent to the manufacturer for development, is reversed to a positive by chemical treatment, printing on a regular positive film is unnecessary. For this reason the expense is only about ⅙ that of making standard size motion pictures.

FILM LIBRARIES. Although movies made in and around the home are so completely fascinating in themselves, nevertheless, the Kodascope offers another feature for the home entertainer. Hundreds of thousands of feet of professionally made pictures have been leased for use to the Kodascope Libraries, Inc.⁠[11] Thus it is possible to rent films to fit any type of entertainment—comedies, dramas, animated cartoons, educational films—everything, in fact, most suitable for home projection,—and new films are being added continually.