The Chemistry of Photography1

Photography is a very complex form of art, which uses standard chemicals and scientific equations.It is a chemical reaction, which occurs when light hits a film or paper emulsion.An emulsion is part of the film or paper, which is very sensitive to light.This is also the part where the chemical reaction takes place.In an emulsion, are small crystals of silver halide, silver bromide, silver chloride, or silver iodide [Eaton, George].These chemical crystals react with light when it is passed through a camera, to create an image on paper [Foto Info].The development of film production has a very simple chemical equation, most widely known as:
Light + Ag(X) â Ag + (X)
This equation expresses how when any form of light is added to silver X, it creates silver plus the X [Mad Scientist].In most cases, the AgX represents one of the compounds above.
In the photographic process, there are three main chemicals used.These are the developer, the stop bath, and the fixer.The developer, or the reducer, is the chemical that completes the reaction with the light exposure, by reacting with the silver, to create metallic silver [Britannica Online].This process is called reduction.Common reducers used are hydroquinone, phenidone, metol, pyro, and absorbic acid.If you combine two of these reducers, it creates superadditivity.Some common combinations are metol and hydroquinone, which produce MQ, or phenidone and hydroquinone, which produce PQ.[Foto Info]
Each of the chemicals used in the developer have their own specific qualities and features.When hydroquinone is used alone, it can be a very slow reducer.When metol is used, it brings out detail very quickly.Phenidone is almost never used by itself.If it is combined with hydroquinone, it keeps detail, but at the same time, it increases contrast.If used alone, it is very fast but has low contrast.One of the less commonly used of these developers is pyro.T…

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