Fox Talbot at the Reading photographic establishment, c 1845.

Early calotype showing the English pioneer photographer William Henry Fox Talbot (1800-1877) taking a portrait of a client on the right. On the left, his former valet Nicolaas Henneman is taking a photographic copy of a portrait. The image is one of a pair taken to illustrate the work of Henneman's 'Reading Establishment' which was in busines from 1843 until 1846 when Henneman moved to London. Talbot invented the first negative/positive proces for producing photographs between 1835 and 1839, and initially sent negatives to Henneman for printing. Talbot's method became known as the calotype proces, and was patented in 1841. For the first time, any number of prints could be made of the same image.