The Cine Technician (1935-1937)

94 The Journal of the Association of CineTechnicians l^ec, 1936-jan., 193; Development and Its Chemicals ARTHUR JAY IN the development of an ordinary negative the silver bromide that has been rendered unstable by the action of light is decomposed, its bromine is taken away and the metallic silver remains. This is exactly the effect that the light itself would have if its action were allowed to continue under suitable conditions. But it is not true to say that the light starts the change and the developer continues it, because in that case the exposure and the development would be interchangeable, that is, more or less exposure with less or more development would lead to the same result. The first requisite of a developer is that it shall be able to. remove bromine from silver bromide, and the second is that it shall not be able to do so unaided, but only when its action has been facilitated by the previous action Fifteen Years [continued from page 92.) This rule does not apply only to Quota pictures, of course, because I have had the misfortune of working on a production that finally cost £100,000 to complete when the main consideration seemed to be to find a strong situation in a magnificent setting to do credit to the leading star. Chiefly owing to the fact that the production staff had not had sufficient conferences with their director, it resulted in the re-writing of the story in four different ways, the employing of five different directors and three chief cameramen, and the ultimate result of a not very successful picture and a financial disaster. Such productions do a lot of harm to the business and there should be no repetition of such failures. It is always surprising to me that I've never heard of an English cameraman who has become a successful director. It would seem that the photographer, who is the director's right-hand man and has worked on good, bad and indifferent pictures should, given the opportunity, be in a position to choose his story and, through the medium of the camera, offer the finest interpretation ofit. He is in a position to know, through experience, just where to place his camera to advantage ; whereas a good percentage of the directors to-day, in all fairness, don't know the difference between a 40 mm. lens and a 100 mm. They certainly don't know how to use it to advantage. Also, except in rare cases, the photographer is the only person to see the advantage of any trick shot that means anything. In my experience the only other department to contribute to the directorial chair, is the Editor. His experience in the Cutting Room is naturally invaluable. It just remains to find the right one who can collaborate with the right cameraman and story writer, when the results should be worth looking at. In conclusion, I should like to say that I am happy and proud to be associated with the British Film Industry. Having grown up with it I can quite realise, with the new studios being built, and new equipment being designed, what a grand profession this can be. There is just the question of stabilising it, and the co-operative spirit, which must lead to better pictures. of light or its equivalent. Whatever is the primary agent employed, it is desirable to be able to adapt it to varying circumstances by accelerating its action or retarding it, so that it will do its work in a steady and well-balanced manner. The mixture used for developing, therefore, consists among other things, of the developing agent proper, an accelerator, a retarder and a preservative. The developing agent as it takes bromine from the silver bromide combines with it, and the product of this combination is usually deep in colour. This, if uncontrolled, would stain the negative. The preservative, as a rule sodium sulphite, prevents this and so keeps the negative clean. The four active constituents of a developer are : — 1. The Reducer — i.e., Hydroquinone or Metol. 2. The Accelerator — i.e., Sodium Carbonate, the alkali which sets the reducer working. 3. The Restrainer — i.e., Potassium Bromide. 4. The Solvent and Dilutent — i.e. Water. Hydroquinone, when solid, is gradually affected by the air and becomes brown, though the change is very slow. It should, therefore, be kept in well-stoppered bottles. In solution it is more readily oxidised, especially if a small quantity of alkali is present, such as is frequently met with as an impurity in sodium sulphate. The solution becomes yellowish and then brown, but it does not alter . at all rapidly and unless it has become markedly brown, it probably retains most of its original developing power. In the absence of any alkali and especially if the solution is slightly acid, it will remain practically unchanged for a long time. Metol in a solid form remains unaltered for a long time if kept in a well-corked bottle. Its aqueous solution soon turns brown when exposed to air, but if it is mixed with sodium sulphite the discoloration is prevented for a considerable time. In the end the solution becomes yellow, and ultimately brown, but it may retain much of its developing power even after it has become somewhat dark brown, provided that no precipitate has formed. Potassium bromide, either solid or in solution, remains unchanged. , Borax does not alter either in the solid state or in solution. Sodium carbonate contains, when pure, as much as 63° 0 of water and only 37° o of true sodium carbonate. It somewhat rapidly loses water when exposed to air and the large transparent crystals crumple down into a powder consisting of very small crystals of monohydrated sodium carbonate, which contains only 14?,",, of water and 851 °o of true sodium carbonate. Sodium sulphite, when in solid form, slowly absorbs oxygen from the air and is superficially con\-erted into sulphate, the change proceeding further and more rapidly in a moist atmosphere than in a dry one. In a properly stoppered bottle the amount of alteration is as a rule but slight. Aqueous solutions of the sulphite have a greater tendency to absorb oxygen and the oxidation takes place more rapidly in dilute than in concentrated solution.