A. Film. B. Top loop to allow for the pulling down of the film during the intermittent movement. C. Magazine to hold the blank film. D. Magazine to hold the exposed film. E. Claw device which pulls down the film three-quarters of an inch for each picture. F. Sprocket-wheels. G. Exposure field. H. Focusing-tube. I. Eye-piece for focusing. J. Shutter. K. Lens. L. Film gate.
The patterns of the shutters in camera and projector differ. That of the projector is three or two parted, as stated in our observations previously made. A camera shutter is a disk with an open section. The area of this open section can be varied to fit the light conditions.
TYPES OF CAMERA AND PROJECTOR SHUTTERS.
The general practice relative to taking motion-pictures is to have one-half foot of film move along for each turn of the camera handle. Eight separate pictures are made on this one-half foot of film. But in a camera that the animated cartoon artist uses, but one turn of the handle for each picture is the method. In most cameras the gearing can be changed to operate either way. To photograph drawings in making animated films a good reliable instrument is necessary, and requirements to the purpose should be thought of in selecting one. One important matter that may be mentioned here is that there should be an easy way of focussing the scene. Generally in taking topical pictures and views, an outside finder and a graduated scale for distance and other matters is made use of, but for drawings it is essential to be able to focus on a suitable translucent surface within the exposure field in the camera.
There are certain numerical formulas that those going into motion-picture work should learn at the start. It is well, too, for the general reader, even if he is interested only as a matter of information to take note of them. Their comprehension will help to a better understanding of how both the ordinary photographic film, and the film from animated drawings, are made, prepared, and shown on the screen.
As the ordinary phrase goes, any single subject in film form is spoken of as a reel; but in strict trade usage the word means a length of one thousand feet. As it is generally reckoned, sixty feet of film pass through the projecting machine every minute. This means that a reel of one thousand feet will take about seventeen minutes. Now with sixty feet of film crossing the path of light in one minute, we see that one foot hurries across in one second. And as sixteen little pictures are contained in one foot of film, we get an idea of the great number of such separate pictures in a reel of ordinary length. All these particulars—especially that regarding the speed at which the film moves—are vital matters for the animated cartoon artist to keep in mind as he plans his work.
ONE FOOT OF FILM PASSES THROUGH THE PROJECTOR IN ONE SECOND
MAKING ANIMATED CARTOONS