Louis Daguerre develops the daguerreotype process

Background. A paragraph appended to a September 1835 Journal des artistes review of one of Daguerre's Diorama spectacles passed along a rumor circulating in Paris studios that Daguerre had found the means to collect, on a prepared plate, the image produced by the camera obscura, with a preparation said to preserve it for an indefinite time. By April 1837, Daguerre remarked to Isidore Niépce that his equipment for taking daguerreotypes was ready, needing only good weather. When the Paris correspondent of The Athenaeum reported the 1839 public announcement, he noted the daguerreotypes then being produced were considerably better than ones he had seen four years earlier.

Technical Development. The 1835 rumor described images projected by an ordinary camera obscura leaving an imprint in light and shade on a prepared plate. With uncommon exceptions, daguerreotypes made before 1841 were of static subjects such as landscapes, buildings, monuments, statuary, and still life arrangements. Henry Fox Talbot's paper-based calotype, introduced in 1841, allowed unlimited copies by contact printing but showed obtrusive paper grain and could not match the daguerreotype's extremely fine detail. Gilding, also called gold toning, was added to Daguerre's process by Hippolyte Fizeau in 1840.

Public Announcement. Efforts to interest private investors failed, leading Daguerre to go public in 1839. The French government acquired his rights in exchange for pensions for Daguerre and Niépce's son. On 19 August 1839, the government presented the invention as a gift to the world, publishing complete working instructions. This event established 1839 as the year photography was made public.