The Cine Technician (1939)

Aug. -Sept., 1937 THE CINE-TECHNICIAN 81 The Projection of Lenticular Colour Films J. G. CAPSTAFF, 0. E. MILLER and L. S. WILDER (Kodak Research Laboratories) INTRODUCTION THE lenticular film colour process, in common with other additive colour processes, involves a large loss of light by absorption in the colour filters necessarily used in the projection system. Therefore, it requires so much more illumination than is needed for projecting black and white pictures that it was believed until recently by many responsible persons in the industry to be impossible to show these pictures properly even in the average theatre, not to mention the de luxe houses with screens from 25 to 35 feet in width. To illustrate the seriousness of the problem, it was estimated that about ten times the normal amount of light would be needed. The colour filters used for projection during the earlier experimental work had a transmission of only 12 or 13 per cent., and the intensity was further reduced by the lenticular surface of the film support. The Kodak Research Laboratories recently undertook to make a systematic investigation of the possibilities of lenticular film projection and to give an actual demonstration in a de luxe theatre. A preliminary survey of the problem indicated quite a number of possible ways in which the screen illumination could be increased. Some of these, which were temporarily laid aside for practical reasons, will not be mentioned except in the concluding remarks. With a desire to limit the investigation to the use of already existing projection equipment with only minor alterations, the work was pursued along the following lines : 1 . Reduction of the absorption loss in the colour filters. 2. Modification of the optical system to increase its relative aperture. 3. Recovery of part of the light lost because of the shutter. 4. Reduction of the density of the prints. 5. Improvement in the operating conditions of the illuminating system. EXPERIMENTAL WORK Filters Since the greater part of the light is lost due to absorption in the colour filters, the problem of screen brightness becomes progressively easier as the filter transmission is increased. After a certain point, however, the colours of the projected picture begin to lose saturation and appear "washed out." The colour reproduced on the screen can be of no higher degree of purity than that of the projection filters. As the red filter is made lighter, it soon begins to transmit yellow, and becomes an orange red. With such a filter a good red cannot be represented properly on the screen. After a considerable amount of experimental work with dyes and a number of observations with filters the filmcraft each 3/6 net filmcraft illustrated series from all booksellers by Adrian Brunei An epitome of the technique of film production. Every step, from the choice of subject to the final editing, clearly explained by an expert. With appendices by other well-known technicians. film technique by v. i. Pudovkin Pudovkin ranks with the greatest Directors of the cinema and the influence of this pioneer work is found in every modern film. making home movies by d. charies ottiey An up-to-date handbook showing how successful pictures are made and containing many useful hints on technical points which enable the keen amateur to acquire proficiency in the art of movie-making. home processing by Percy W. Harris Even though you prefer to get your processing done for you, this book will well repay perusal, for with closer knowledge of what the film "goes through" will come greater skill and care in the "taking" of your pictures. film titling by G. P. Kendall Types of lettering, the use of home-made and commercial titling outfits, lighting, exposure, animated and trick titles — all comprehensively explained. film acting by V. I. Pudovkin "This book .... with its reconsiderations and clarifications of film problems is invaluable to anyone who recognises a future (and a past) for the Cinema as a serious art." — The Listener. Each 3/6 net or 3/9 post free from : — GEORGE NEWNES LIMITED Tower House, Southampton St., Strand, London, W.C.2 QUACK! QUACK! Just as a quack dentist can make a fearful mess of your mouth so can a quack studio make a shocking mess of your film. We started recording when recording first started and we learned, that recording, to standards demanded to-day, cannot be done with a box of wheels, a few yards of wire, a ball of string and a heap of luck. We have probably the most expensive equipment in any independent studio today, and with the knowledge that we have recorded some 900 successful films, you can, with the utmost confidence, rely on us to turn out an excellent job. If you want quack results you don't want us, but if you demand a really high standard and professional treatment GO TO IMPERIAL SOUND STUDIOS 84 Wardour Street, W.l Ger. 1963 THE RECORDING SPECIALISTS