Film Processing

The Black and White Film Processing Equipment of Current camera films is mostly small-format (35 mm or 6 x 6 cm). They are roll films up to 165 cm long which means that they can conveniently be processed only by suspending them in deep tanks or by coiling them into a spiral. The suspension method is rarely used these days because even where large tanks are the rule, it is preferable to put the films into spirals and suspend them in baskets. The film spiral is the basis of the most commonly used processing method. They are made of plastic or stainless steel. It has a diameter of 8-9 cm and is in the form of two grooved discs separated by a central core. The grooves are simply spaces between the spiraling steel or plastic and the film is slid or sprung into them in such a manner that successive coils are about 3mm apart. That is sufficient for the processing chemicals to circulate freely when the spiral is immersed in a tank. The film must be loaded into the spiral in darkness but once the spiral is in the tank and the lid is firmly in place light can no longer reach the film until the lid is removed after completion of processing.