The Cine Technician (1935-1937)

84 The Journal of the Association of CineTechnicians February, 1936 one through green, and one through blue. But no matter how the three negatives are obtained — what is important is how they are going to be printed on the final positive film. Here it is that the processes differ from each other fundamentally. Gasparcolor film is the first colour film positive material upon which the three negatives may be directly printed each in its own appropriate colour. For the first time, no dyes are used in the processing, no staining, colouring or toning enters into the treatment of the film. This sounds like a miracle, and in one sense it certainly is a miracle. Yet the principle is simple. Imagine three coloured emulsions. That is, emulsions which contain transparent dyes in suspension in the gelatine. These emulsions are coated on the celluloid in layers in the following order. On one .side of the film we have pink, and beneath the pink layer a yellow layei . On the other side of the film is coated a blue layer. Now, these emulsions are so sensitised that we can print them witli coloured lights each in turn, independently of the other. , The layers are sensitised in the following order : The pink layer is sensitive to blue light only, but tlie yellow layer underneath is sensitive to red light also. The blue layer is blue sensitive only. By printing the three layers with coloured lights it is possible to print the film three times upon the three layers independently of each other. The film which is to print the pink layer is printed with blue light, but as the yellow layer lying beneath will not admit blue rays, nothing from this negative is recorded on any layer except the uppermost pink layer. Next, the yellow layer is printed with red light, but as the uppermost pink layer is not sensitive to red light nothing is printed upon tins layer, whereas the yellow layer lying underneath the pink layer is sensitive to red light. It therefore records the red light. Finally, the blue layer (which is blue sensitive) on the other side of the film is printed with the third film, using white or blue light. Obviously only blue light can get through the blue coating and no blue light can enter the yellow emulsion lying beneath. Thus the three layers can be separately printed without the slightest danger of printing more than one layer at a time. The three printings can be done on a single printing machine as fast as normal black-and-white. The subsequent development of the film differs in minor respects from black-and-white, but normal processing machinery is employed. The claims of the Gasparcolor process are : — (1) It is three colour film and therefore gives perfect reproduction of the whole range of colour. (2) It is photographically produced print and does not rely upon dyes, colour-toning, or chemical treatment for the colour. (3) It is accurately reproducible by standard norma photographic practice and almost standard processing equipment, whereas other colour processes require specially equipped processing laboratories. THE FIRST GENERAL FILM DISPATCH HWlllJl'l fILM LIfiRAftY fILM D€SPATCH EDITING BAYS (4) It is as transparent as black-and-white film and requires no more than the normal illumination for projection. It is virtually a grainless pure colour image. (5) No addition of any kind is required to the projector. It can be exhibited anywhere at any time in any projector. (6) It does not show scratches moi'e than black-and white film. (7) Sound track is black on a transparent red background giving normal results. Gasparcolor film is double-coated, and projectionists very generally have been of the opinion that it is difficult to focus double-coated colour films. This opinion is based on an accurate observation, but the cause of the difficulty does not lie in the fact of the film being double-coated. First of all, previous processes have not had sharp pictures to focus. That the double-coated film cannot be the cause is shown by the fact that the distance apart of the blue image and the red-yellow images is, at the most, four and a half thousandths of an inch. Now, assuming a projection distance of 100 ft. and a 4-in. lens focus, the distance apart of the sharp projected pictures could not be more than l|-in. Therefore, it is absurd to blame the double coating of the film. The sound-track of Gasparcolor film, liaving a red background, it may be found advisable to increase the volume by one or two steps. Naturally it is impracticable to use non-red-sensitive photo-electric cells. The question of the colour characteristics of the illuminant in relation to the projection of a colour film involves too many factors to be discussed in this brief description ; but this aspect is really very important and it will have to be taken into consideration by both the producer and exhibitor of colour films. A large difference in the colour temperature of the light source can cause a tremendous difference in the appearance of the colours upon the screen. — (Reprinted from The Projectionists' Journal). Reduced Railway Charges for Cinematograph Apparatus As a result of correspondence with the London, Midlaiul and Scottish Railway Company, we are pleased to report the following reduced railway charges for cinematograph apparatus, conveyed to the Association in a letter, dated 23rd December, 1935, from the Chief Commercial Manager : "I would inform you that it has now been agreed between the Group Railway Companies that the free weight allowance and excess luggage charges for ordinary passengers shall also apply in the case of a Cinematograph Camera and Tripod accompanying a Cameraman travelling to take pictures for inclusion in newsreels. These free weight allowances are 150 lbs. for each passenger travelling 1st class, 120 lbs. 2nd class, and 100 lbs. 3rd class." We are pleased that the Association has boon alilo to render this service to the Film Industr\ .