Amateurs usually process films in developing tanks. In this type of development roll or miniature film is wound around a reel with a spiral groove, which keeps adjacent turns separated and allows access by the processing solutions. Once the tank is loaded (in the dark), processing takes place in normal light, the processing baths (developer, intermediate rinse, fixer) being poured into the tank at the appropriate intervals. Sheet films are similarly treated in small tanks or held in hangers and immersed sequentially in the different processing solutions. Large-scale commercial processing laboratories use machines that automatically feed the films through the ...(100 of 19384 words)