Amateur Photographer & Cinematographer (1937)

August 4th, 1937 iHf AMATEUR PHOTOGRAPHER a 6 CINEMATOGRAPHER a A dap ting Larger Cameras for 35-mm. Film This article shows how any ordinary roll-film camera can be adapted for 36-exposure lengths of standard cine film. to prevent the mask from slipping up and down. The view-finder, or in the case of a reflex the top focussing screen, must also be masked to give the same reduced angle of view. Black paper gummed on will suffice for this. Fig. I. Adapting a standard spool for 35-m;/!. film. AT holiday time, when exposures follow one another in rapid succession, a 36-exposure film rescues one from the nuisance of too frequent reloading. There is no great difficulty in adapting a camera to take miniature film ; the only two essential requirements are a mask for the back of the camera, and spools to take the narrower film. For the spool, all that is necessary is to gum a strip of half-inch material around each end of a couple of empty bobbins. Passe-partout binding, or even a worn-out typewriter ribbon, can be used. They should be left at least a day to dry through. The mask. Fig. 2, consists of a small piece of stiff card cut to slip just inside the picture-space at the back of the camera. In the centre of this card a hole 24x36 mm. is cut. On one side is stuck a pair of paper strips which will prevent the mask from falling through the camera aperture and at the same time will form a channel along which the 35-mm. film will slide. On the other two edges of it, two further strips may be required, according to the character of the individual camera Fig. 2. The mask, shown with and without the strips used for fitting to the camera. Fig. 3. Putting the mask in place. 'M First, the film is wound on to a spare bobbin. After trimming the free end to fit the slot, the film can then be started on to the top bobbin in the ordinary wav, as in Fig. 4, when the camera can be closed and is ready for work. Loading and unloading must be done in the dark unless a paper backing is used as described below. There are three ways to determine how much one should wind on for each exposure The simplest is to make one complete revolu¬ tion of the winding-knob each time. This method is certain and easy, but it produces a space, increasing with each exposure, between negatives, and so is a little wasteful of film. Another way is to make a dial, either on the knob itself or around it, as shown in Fig. 5. This is achieved by inserting a strip Fig. 4. Loading the camera in the dark-room. of film, winding 8 perforations (one frame) at a time, and marking a spot or number on the dial for each. In using either of these two methods it is essential to seal up the red window of the camera, because the film has no protective paper. Another scheme is to use a length of the backing-paper which has been saved from ordinary spools, and cut it carefully to a width of 35 mm. This is wound on to the top spool with a strip of film inside it, and a number is marked on the backing -paper, in the appropriate place for the red window, for each frame. Once one backing-paper is marked off, others can be made from it, and as many spools of film as desired can be made up. Each such home-made spool will hold less than 36 exposures, but this scheme offers the great advantage of allowing loading and unloading to be done in daylight. G. K. S. Fig. 5. Marking out a winding-indicator and picturecounter. 18 131