Henry Fox Talbot - Invention of Calotype Process

Invention of Calotype Process

Talbot said he engaged his photographic experiments beginning in early 1834, well before 1839, when Louis Daguerre exhibited his pictures taken by the sun. After Daguerre's discovery was announced (without details), Talbot showed his five-year-old pictures at the Royal Institution on 25 January 1839. Within a fortnight, he freely communicated the technical details of his photogenic drawing process to the Royal Society. Daguerre would not reveal the manipulatory details of his process until August. In 1841, Talbot announced his discovery of the calotype, or talbotype, process. This process reflected the work of many predecessors, most notably John Herschel and Thomas Wedgwood. In August 1841, Talbot licensed Henry Collen, the miniature painter (1798–1879) as the first professional calotypist. Talbot's original contributions included the concept of a negative from which many positive prints can be made (although the terms negative and positive were coined by Herschel), and the use of gallic acid for developing the latent image. In 1842, for his photographic discoveries detailed in his The Pencil of Nature (1844), he received the Rumford Medal of the Royal Society.