Film processing is a responsible job, essentially a consistent, controlled routine. It is done by using processing solutions; from these the gelatin of the emulsion absorbs chemicals, which then react with silver halides, in the case of developers differentiating between exposed and unexposed crystals. Using liquid you can also wash out by-products and chemicals from the emulsion without disturbing the actual image.
Processing is ideally suited to automatic machinery, which gives very consistent results but is expensive to set up and really only justified for photographic departments and laboratories which have a high throughput. This chapter therefore concentrates on the processing of different kinds of camera films in small ...