On January 9, 1839, the Daguerreotype photo taking process was announced at the French Academy of Science. From the article:
"Daguerreotype Photography
Photo of Daguerreotypes.
Daguerre experimented for years with increasing the sharpness of the lens in the camera obscura and working at discovering the reaction of various light-sensitive materials when applied to different surfaces. He corresponded with Joseph-Nicephore Niepce, who was engaged in similar efforts. They worked at permanently capturing the images they saw in the camera obscura, and critiqued each other's work with each attempt. It was essential that they prepare a medium to be sensitive to light, using a lens and light to form an image upon it, but then making that same medium insensitive to further exposure so that the resulting image could be viewed in light without harming it. Niepce passed away in 1833, but Daguerre continued some correspondence with his son, Isidore.
By 1835, word began to spread around Paris that the city's favorite master of illusion and light had discovered a new way to enchant the eye. In January of 1839, the invention of a photographic system that would fix the image caught in the camera obscura was formally announced in the London periodical The Athenaeum.
Louis Daguerre called his invention "daguerreotype." His method, which he disclosed to the public late in the summer of 1839, consisted of treating silver-plated copper sheets with iodine to make them sensitive to light, then exposing them in a camera and "developing" the images with warm mercury vapor. The fumes from the mercury vapor combined with the silver to produce an image. The plate was washed with a saline solution to prevent further exposure.
Daguerreotypes offered clarity and a sense of realism that no other painting had been able to capture before. By mid-1850's, millions of daguerreotypes had been made to document almost every aspect of life and death. Photography was on its way to becoming quite commonplace; portrait studios—and eventually, everyday picture-taking— would catch on in a flash.
*(From the Latin, "dark chamber") A light-proof box in which images of outside objects are projected through a lens onto a facing surface. It was used as a drawing tool and helped artists to render more accurate three-dimensional scenes."