A hand-coloured stereoscopic daguerreotype portrait of Henry Claudet, taken at the studio of Antoine Claudet (1797-1867). Henry Claudet was one of Antoine Claudet's sons and possibly an assistant in one of his photographic studios. 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