Photographic chemicals

chemical compound

light-sensitive colloid

Amidol is a colorless crystalline compound with the molecular structure C6H3(NH2)2OH. It is a dihydrogen chloride salt and is used as a photographic developer. It was introduced as a developing agent for photographic papers in 1892. It is unusual amongst developing agents as it works most effectively in slightly acid conditions rather than the strongly alkaline conditions required for most other developers. As amidol ages it changes color to a dark red-brown. Developing dishes and equipment used to prepare amidol solutions are also frequently stained brown, a stain that is very persistent.

Phenidone (1-phenyl-3-pyrazolidinone) is an organic compound that is primarily used as a photographic developer. It has ten to eighteen times the amount of efficiency and stability as Metol, capable of achieving the same level of development in both less time and at a lower concentration. It also has low toxicity and unlike some other developers, does not cause dermatitis upon skin contact. As a developer, Phenidone is typically used in conjunction with hydroquinone for black and white photography and performs better at lower pH levels (about 9.8-10.4). This is comparable to Metol whose workin

chemical compound

mix of chemicals used in the final step in the photographic processing of film or paper

thumb|RODINAL Rodinal is the trade name of a black and white developing agent produced originally by the German company Agfa based on the chemical 4-aminophenol. Rodinal is a popular high acutance black and white developer and is used at different dilutions for development in rotary machines, by agitation, as well as for stand development.

chemical compound

alt=35mm film developed in caffenol.|thumb|135 film|35 mm film developed in caffenol. Caffenol is a photographic alternative process whereby phenols, sodium carbonate and optionally vitamin C are used in aqueous solution as a film and print photographic developer.

Glycin, or N-(4-hydroxyphenyl)glycine, is N-substituted p-aminophenol. It is a photographic developing agent used in classic black-and-white photography. It is not identical to, but derived from glycine, the proteinogenic amino acid. It is typically characterized as thin plates of white or silvery powder, although aged samples appear brown, as is typical for aminophenols. It is sparingly soluble in water and most organic solvents; it is readily soluble in alkalies and acids.

chromogenic film and paper used in photography

chemical compound