Dancing in the Dark - A Guide to Developing Black & White Film

Black and white film is developed, or processed, when the photographic film, which has already been photographically exposed, is treated with certain chemicals to produce a positive or negative image. Photographic developing therefore changes the latent image as contained on the exposed photographic film into a visible image, which then becomes permanent and no longer able to be affected by light.

Black and white film is not developed in the same way as color film and there are actually several different ways in which film can be developed, depending on factors like the composition of the photographic film or paper. The gelatin-silver process is the most common developing method and can be used regardless of the photographic film’s exact composition. There are two distinct ways in which black and white photos can be developed using this silver-gelatin process, being the basic black and white development process and the black and white reversal process and both of these processes will involve the photographic film’s being treated in a number of chemical baths.

The basic black and white developmental process begins by the film’s being soaked in a developer, which transforms the image to latent silver, and which is then terminated by placing the film in a stop bath or clean water rinse as this halts the action of the developer. The film is then soaked in a fixer, which gets rid of any remaining silver halide salts and makes the image permanent and no longer sensitive to light. After the fixer treatment, the film is rinsed in clean water and then in a diluted non-ionic wetting agent to help it to dry and to remove any hard watermarks. After that, the film, which is now called a negative, is then dried, cut and put into clear plastic sleeves. The image contained on each negative is then enlarged and mirrored onto photographic paper, thus creating a photograph.

The black and white reversal process is identical to the basic black and white developmental process except that it has several further steps. The added steps come in after the film is treated in the stop bath and comprises bleaching the film and so eradicating the developed negative image. The film, which now contains a latent positive image of undeveloped and unexposed silver halide salts, is then fogged by intentionally exposing it to light or certain chemicals to degrade the image quality. Those silver halide salts that still remain are then developed, in another developer, and a positive image is created. After that, the basic process picks up again at the fixer treatment stage.

Toning is a further step in the processing of black and white emulsions and is used to give pictures a certain background color. A well-known example of toning is found in sepia pictures.

Black and white film can either be developed at home in small scale processing set ups or can be developed commercially, either in professional processing studios or in automatic processing machines. The processing method chosen depends on the photographer’s available budget and what he intends to do with the photographs.

For more information on developing film, visit http://www.pfe.com/p145002-developing-color-film.cfm