British Kinematography (1950)

March, 1950 coote : colour kinematography 89 of the least important image (from the standpoint of definition) to the bottom of the tripack where partial diffusion is inevitable. A print on Du Pont Release Positive, now to be projected, was printed and processed by Consolidated Film Industries at Fort Lee, N.Y., from three-strip negatives made in a Dufaychrome camera. It is probable that these were the first live action subjects to be printed on the new stock. Unified Perforation One other point of interest about the film just projected is that it is perforated with Dubray-Howell perforations. The common type of film perforation for both positive and negative stock is being proposed for adoption, as an American standard.9 The practice with Technicolor, Cinecolor and Dufaychrome is to use Bell & Howell type negative perforations for both camera negatives and release prints, but the projection life of film perforated with negative perforations is considerably less than that of film having the present type of positive perforation. The problem is by no means a new one, in fact in 1932 Dubray & Howell proposed a combined positive and negative perforation having a shape similar to the existing positive perforation, but with the height of a negative perforation. Nothing was done in the matter at that time, although another attempt to establish such a standard was made in 1937. This also failed and nothing more appears to have been done in the matter until three years years ago, Arthur J. Miller, of Consolidated Film Industries, announced that the Trucolor process would use safety-base stock perforated with the Dubray-Howell perforations. The Consolidated Laboratories use Duplex machines for their colour printing, and since they have to print from negatives bearing Bell & Howell perforations, the printing machines have been modified to work with three instead of the usual two register pins. The third pin is fully fitting in width, but reduced in height and is placed on the same side but one perforation above, the normal full-sized pin. Cinecolor Processing Specimens of three-colour Cinecolor were shown earlier this year, but as they had originated from 16 mm. Kodachrome it would not be fair to base an opinion on them. It may well be that the three-colour process, like twocolour Cinecolor, depends upon duplitised stock, and that this is processed to produce a cyan image on one side and a magenta image on the other — possibly by toning with iron and nickel-dimethylglyoxime respectively — and then, before fixing, one side of the* stock is printed again to produce a silver image to be converted into a silver iodide mordant which is in turn used to form a yellow-dyed image. If this procedure is followed, obviously there will be several stages at which floating, or similar unilateral treatment, is involved, and Cinecolor, by reason of the considerable experience they have had with their two-colour process, should be very well equipped to undertake such processing.10* IV. BIPACK PROCESSES Pictures are still being made in two-colour Cinecolor, and it has been announced that a corresponding process is to be operated in this country by Radiant Laboratories. We shall all await the results with interest. An interesting innovation in the use of bipack has been introduced by Cinecolor. Previously, all two-colour photography in America has been carried out with the well-known Bell & Howell type bipack magazine ; this form of magazine works very well in the 400 ft. size, but becomes impossibly *// has since been disclosed that the Cinecolor process depends upon the combination of an iron-tonea . cyan image with dye-toned magenta and yellow images, the cyan and yellow images being formed on one side and the magenta image on the opposite side of duplitised positive stock.