when was the first glass negative invented
In 1839, John Herschel made the first glass negative, but his process was difficult to reproduce. Slovene Janez Puhar invented a process for making photographs on glass in 1841; it was recognized on June 17, 1852 in Paris by the AcadÃ©mie Nationale Agricole, ManufacturiÃ¨re et Commerciale.