Talbotype

Talbotype, or calotype, early photographic process invented by the English scientist W.H. Fox Talbot in the 1830s. Talbot first made the photographic paper light-sensitive by treating it with sodium chloride and silver nitrate solution. When he then placed the treated paper in a camera and exposed the paper to light, a negative image formed on it, which he then developed in gallo-nitrate of silver to produce the talbotype. Though this method did not produce pictures as clear as the daguerreotype, any number of prints could be made from the talbotype negative.

See also: Photography.