ABSTRACT
The refinement of photographic processes during the 1830s culminated in the announcement to the public in 1839 of two quite different techniques – originating in France and England – for producing a permanent positive image. Both involved the use of a homemade camera box with a lens. 1 That of Louis-Jacques-Mandé Daguerre, which captured the object on a silver-plated metal ground (the daguerreotype), achieved a significantly greater precision of detail, but was limited to unique positive images. That of William Henry Fox Talbot, based on the production of a paper negative from which large numbers of positive prints could be made (which he called talbotypes, but soon renamed calotypes), was more effective in providing multiple copies and thus widespread access to visual information. 2
