Dry collodion plate camera, 1860.
© National Media Museum / Science & Society Picture Library
An early sliding box type dry collodion plate camera, with a lens made by the London Stereoscopic Co. Frederick Scott Archer (1813-1857) invented the wet collodion process that replaced the calotype and daguerreotype processes. Popular from around 1855, it was the first photographic process that produced finely detailed negatives, of which more than one copy could be made, and for this reason is widely considered one of the most important developments in photograpy. The gelatin dry collodion process was its replacement and was the forerunner of today's photographic film processing.