William Henry Fox Talbot

William Henry Fox Talbot well known for his calotype, an early photography technique.

While the development of daguerreotype in France , Talbot of Great Britain invented this technique , a sheet of paper coated with silver chloride was exposed to light in a camera obscura; those areas hit by light became dark in tone, yielding a negative image.

In 1835 published his first article documenting a photographic discovery, that of the paper negative. The photogenic drawings were basically contact prints on light-sensitive paper, which produced dark and spotty images .In 1840s he improved the technique and called it calotype which took shorter exposure time.Talbot patented his process in 1841.Talbot’s The Pencil of Nature (1844–46), was the first book with photographic illustrations .The book contains salted paper prints, which explains his process and various uses of photography.

The revolutionary aspect about his discovery of the chemical (gallic acid) that could be used to develop an image on a paper .The developed image on the paper was fixed with sodium hyposulfite .Talbot’s process was superior in this respect to the daguerreotype, which yielded a single positive image on metal that could not be duplicated.