The Teeth on the Unused Edge are Covered with a Piece of Brass Curtain Rod
Home-Made Motion-Picture Camera and Projector
By Charles Frank
In Three Parts—Part I
(Fig. 1)
Motion pictures are made and reproduced by means of a camera and projector, each having a similar mechanism that would seem entirely too complicated for the average person to construct at home, yet a correspondent of the Nickelodeon has devised a simple rotary cylinder shutter that can be substituted for the complicated parts. While this simple cylinder shutter is not claimed to be infringing on existing patents, yet, as it has no commercial value, there would be no objection on this score. The instruments described are nothing more than toys, and if the amateur photographer can secure a few dozen feet of animated photographs about the home that are dear to his heart, and reproduce them on a screen, it will have served its purpose. The camera and projector described uses standard film, 1-3/8 in. wide, with perforations every 3/16 in.
The Camera
The ordinary hand camera for making still pictures consists of a light-tight box with a lens at one end and a sensitized plate or film at the other. The motion-picture camera (Fig. 1) is nothing more than a hand camera with a mechanical device for stepping a long roll of film through a space in the focal plane of the lens at a speed of about 16 pictures a second, and stopping the film long enough to make the requisite exposure on each division. The first thing to consider is the lens. A lens having ordinary speed for a hand camera, and one with about 3 in. focal length will give satisfactory results. If one does not care to purchase a lens, a small 1-1/2 in. or 2 in. reading glass can be used, if it is stopped down, or a lens may be taken from a hand camera. The width of the camera from front to back (W, Fig. 2) must be determined by the focal length of the lens. The dimensions given in the drawing are only approximate, and they can be changed if the camera is to be used in making an extra long film negative.