The Cine Technician (1939)

March-April, L938 I X K T ( ' II N 1 ( • I A N 200 made of the bipaek process. Although the bipack permits of yielding only two colour separation negatives, the colour rendering obtained by mixture of two basic colours is for many purposes quite sufficiently good. The colour separation negatives are produced, in the Agfa. Bipaek, by using a front film sensitive to blue-green, over which is placed a thin filter layer of a red colour. The back film is panchromatic. Light reaching the combination from the lens, records the blue-green separation negative on the front film, while, the back film records the red component. The filter on the front negative stops all other rays than red from affecting the back film. Experiments made with the object of using the bipack principle for three-colour work by employing a front or hack film with emulsion on each side, are unsatisfactory on account of the lack of sharpness of the image. 3. — 'The Technicolor Process The Technicolor Corporation of America have developed for their three-colour process a special type of film camera using the beam-splitter principle, and in which the light from the lens is divided by two prisms face to face with a gilded semi-transparent mirror between them. A special picture aperture is provided in tin/ camera for each of the two beams: behind one of them, in front of which is placed a green filter, a single panchromatic film moves; behind the other, which has a magenta filter in front of it, a bipack film similar to the Agfa type runs. Here the front film is again sensitive to blue, while finback film is panchromatic, a red filter layer on the front film again keeping the blue rays from the back film. Three simultaneously exposed primary records, entirely free from parallax, are produced. 4. — Screen Processes By placing a screen of tiny colour elements (regular or irregular colour mosaic screens) in front of the photographic emulsion, or by using a lenticulated or line screen in conjunction with a three-colour filter in front of the lens, three separation records are produced simultaneously side by side on a single emulsion, since each complete element of the screen produces three primary records from the light falling on it. In amateur photographic practice, screen-colour, linescreen and lenticulated-screen processes are used on flat films or miniature films (e.g., AgracolorUltra, Lumiere Autoehrome, Agfacolor and Kodacolor lenticulated film, and Dufaycolor regular colour mosaic), the original film exposed in the camera being reversed direct to a positive instead of a negative. For the taking of cinematographic pictures the lenticulated film alone is of interest, though the exposure lighting required is very high — approximately ten times that needed for ordinary black-and-white work. This is partly due to the fact that owing to the high requirements in regard to fine-graineness and resolving power of photographic emulsions necessary in lenticular processes, it is not possible for utilising similar high sensitised emulsions as they are common with black-andwhite cinematography. In recent months a short feature production has been made by the Opticolor lenticular film process. It was recorded on lenticular reversible stock and printed on the same material. The principle of this process may be briefly described in the following terms. At the optical centre of the lens is placed a colour filter, which has three strips of the primary colours side by side and can be placed either vertically or horizontally. A panchromatic film is used in the camera, the celluloid side tinned to face the lens. This side of the film is impressed with a very large num. THE NAME Shaw Jones THE TIME Any Time THE PLACE 49, Greek St. THE NUMBER Gerrard 6716 So Just PHONE, CALL or WRITE if you want Particulars of Our Day and Night Newman Sinclair Camera Hire Service This consists of a Fleet of 8 Equipments, each Camera being fitted with from 3 to 5 Lenses