A hand-coloured stereoscopic daguerreotype of Mrs Antoine Claudet, with, probably, her mother-in-law, taken at the studio of Antoine Claudet (1797-1867). In 1839, the Daguerreotype, invented by Louis Jacques Mande Daguerre, became the first photographic process to be announced to the public. A highly-polished silver surface on a copper plate was sensitised to light by exposing it to iodine fumes. After exposing the plate in a camera it was developed with mercury vapour. Daguerreotypes are unique images which may appear as a positive or negative depending on how light hits the surface. A stereograph is a pair of photographs which, when viewed through a stereoscope, give the appearance of three-dimensional depth.
© National Museum of Science & Media / Science & Society Picture Library