Amateur Photographer & Cinematographer (1933)

hi AMATEUR PHOTOGRAPHER o 6 CINEMATOGRAPHER a August 2nd, 1933 mateur NEWS, NOTES AND MATTERS OF IN¬ TEREST FOR ALL CINEMATOGRAPHERS USING AMATEUR CINfi APPARATUS. Cinematography Cine Photography in Colour the Beginner. By I. E. DAVIES. NEARLY every enthusiastic amateur cinematographer has ambitions to take moving pictures in colour. It can be said that the owner of a 16-mm. cine camera has a great advantage over the amateur or professional user of 35-mm. stock, in that he has the means, ready at hand, to obtain colour results which for fidelity in tone have, up to the moment, been unsurpassed. The only successful natural colour system for the cineamateur was introduced in 1929 by the Eastman Kodak Company of America, and briefly consists of a film having a specially embossed celluloid base. These embossings comprise multitudinous microscopic lens-like prisms. Anv pictures taken on this film by means of an ordinary lens would result in black-and-white images, but for the purpose of colour recording a special three-colour filter is fitted to the lens, this filter comprising the three primary colours, red, green and blue. It will be clear that owing to the density of the three-colour filter, quite a lot of light will be absorbed, and it is therefore an essential to success that a wide-aperture lens, such as an f/1.8 or f/1.5, be used. Hitherto it has been essential to have bright direct sunshine for colour results, nothing below a light value of f/8 proving of much success. With the advent of the new super-sensitive colour film bright sunlight is not so essential, successful exposures now being obtained under conditions which pre¬ viously would have proved impossible. The advantages of the system are many, the disadvantages few. One disadvantage is mentioned and should be noted particularly. There is a distinct tendency to lose very fine details. Provided, however, that broad masses are existent distant scenes are very effective, and close-ups in good light are very natural and attractive. The very nature of colour is light. Colour, after all, is reflected light rays. The less the light the more subdued the colours. The colouring of a landscape differs according to the light available — towards dusk there is little colour dis¬ cernible. This fact must always be borne in mind. It is distinctly unfair to expect a film to register colour which may not exist. As mentioned above, a wide-aperture lens must be used in conjunction with the tricolour filter. The lens is to be operated at its widest aperture. As a rule the colour fitment is so adjusted that it is impossible to place it in position unless the lens is opened to its maximum aperture. As the iris diaphragm is thus locked at its maximum opening, some other means must be provided to compensate for differing light conditions. For this purpose two grey glass filters, termed neutral density filters, are utilised. These two filters are of different absorbing values, and according to the intensity of the light available, so does the use of filter No. 1 or 2 depend. With each roll of film a small metal diaphragm is issued, and this diaphragm, known as the ratio diaphragm, must be used with its associated film and with none other. The ratio diaphragm is inserted behind the three-colour filter on the lens mounting, and it is of the utmost importance to see that the proper ratio diaphragm is placed in position when loading the camera. There is no need to disturb the ratio djaphragm when assembled in the lens until it becomes necessary to reload the camera with fresh colour film. The following exposure guide will prove helpful to users of the film : Light Clas¬ sification. Remarks. Exposure. Camera Speed. Dull or in open shade. Dull. — Sky completely overcast, but good light. Do not confuse with very dull. Open Shade. — Subject lighted by large area of sky. No neutral den¬ sity filter. Half. Slightly Cloudy. Slightly Cloudy. — Sun just ob¬ scured, no distinct shadows cast. Also for clear days when only part of subject is in sunlight. No neutral den¬ sity filter. Normal. Direct Sunlight. Direct Sunlight. — Full sunlight, distinct shadows cast. Neutral density No. 1. Normal. Intensely Bright. Intensely Bright. — Unusually bril¬ liant sunlight, without large shaded areas. Neutral density No. 2. Normal. Early or late in day, increase the exposure by changing the N.D. filter or decreasing the camera speed. For the purpose of finding how to expose for a Kodacolor scene, find by means of a meter what exposure would be re¬ quired for the same shot on ordinary black-and-white film. Having arrived at the diaphragm opening necessary for blackand-white shots, reference can be made to the figures below for the corresponding Kodacolor exposure. Lens Stop Reading. Kodacolor Exposure. F/16 to f/2-2 . . . . Use neutral density filter No. 2. F/3tof/n .. .. Use neutral density filter No. 1. F/5.5 to f/8 . . . . Use no neutral density filter. F/4 to f/5.5 . . . . Use half (8) speed, no neutral density filter. Below f/4 . . . . Unsatisfactory. Remarkable action subjects for the amateur cine worker are to be secured at athletic sports meetings which are being held in all parts of the country. Many of the hints given for ‘‘still" photographs of these subjects in an article in this issue apply also to cinematography. Il6 24