Frederick Scott Archer
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Frederick Scott Archer, born in 1813 and died on May 2, 1857, invented the wet collodion process and the calotype technique. The collodion process, invented in 1851, involved coding a glass in cellulose nitrate and iodide and then placing the plate into a solution of silver nitrate. You then soak the plate in pyrogallic acid after exposing the wet plate to an image. This all took place in what is called a "dark room". The calotype technique was a new way to print a picture in under in hour. In this technique, a piece of paper was put in a camera obscura while covered in silver chloride. the areas hit by light became dark, creating a negative image. The finished image was then placed into gallic acid to develop. After done developing, the paper was put into sodium hyposulfite. To revert the negative image to a positive image, you then copy the negative image on a light sensitive piece of paper. The whole process took less than a minute to copy. Archer invested all of money in his research and eventually died in poverty.
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