Developing Photographic Film

Developing photographic film, which was either silver halide for black and white photography or dye emulsions for color, is a very labor intensive process. Black and white is easier, as the results are not as sensitive to temperature fluctuations in the chemical baths, while color films must be processed with very strict temperature regulation. The area used to process films must be pitch-black since the film must be unloaded and then rolled into film spools for the first steps in development. Once the negatives have been developed, they may be viewed in the light.

I don't know if it's “obsolete.” I still do this for a living. You could make an argument that automated developers and minilabs made hand-developing obsolete, but if you're willing to consider operation of a modern automated lab to be “Developing photographic film” then there are still practical applications for photographic film today. For one thing, many people own 35mm cameras and have not yet or do not intend to upgrade. For another, disposable cameras continue to be in common use and do not yet have any real competition from a 35mm format.

Developing photographic film is certainly not obsolete, mini labs exist in all high streets, sales of film are dropping but they are in no way 'dead'. But developing by hand has become a minority pursuit by those interested in 'art' photography and the craft of darkroom skills.