Frederick Scott Archer, photographic pioneer, c 1840s.
© Science Museum / Science & Society Picture Library
Archer (1813-1857) was the inventor of the wet collodion proces which replaced the calotype and daguerreotype proceses. The collodion proces was the first photographic proces in which finely detailed negatives and more than one copy of a picture could be produced. Most popular between 1855 and 1880, it was eventually replaced by the dry collodian proces. Although this was one of the most important advances in photography, Archer failed to patent his invention and died penniles.