Saturday, July 10, 2010

Deathday: Louis Daguerre 1787-1851 Inventor of Daguerreotype Photography

Louis-Jacques-Mandé Daguerre (November 18, 1787 – July 10, 1851) was a French artist and chemist, recognized for his invention of the daguerreotype process of photography.

Development of the Daguerreotype

"Boulevard du Temple", taken by Daguerre in late 1838 or early 1839 in Paris, was the first photograph of a person. The image shows a street, but because exposure time was over ten minutes, the traffic was moving too much to appear. The exception is the man at the bottom left, who stood still getting his boots polished long enough to show. The first permanent photograph was made in 1826 by Joseph Nicéphore Niépce, building on a discovery by Johann Heinrich Schultz (1724): a silver and chalk mixture darkens under exposure to light. Niépce and Daguerre refined this process. Daguerre first exposed silver-coated copper plates to iodine, obtaining silver iodide. Then he exposed them to light for several minutes. Then he coated the plate with mercury vapor heated to 75° Celsius, to amalgamate the mercury with the silver, finally fixing the image in salt water. These ideas led to the famous Daguerreotype.

The resultant plate produced an exact reproduction of the scene. The image was laterally reversed -- as images in mirrors are -- unless a second mirror was used during exposure to flip the image. The image could only be viewed at an angle and needed protection from the air and fingerprints so was encased in a glass-fronted box.

Some ambrotypes were passed off as Daguerreotypes by being placed in these type of boxes. But the process was cheaper involving a weakly-developed glass card or paper to appear as a positive. Tintypes also were "boxed" as Daguerrotypes.

Daguerreotypes were usually portraits; the rarer views are much sought-after and are more expensive. The portrait process took several minutes and required the subjects to remain stock still. Samuel Morse was astonished to learn that Daguerrotypes of streets of Paris did not show any humans, until he realized that due to the long exposure times all moving objects became invisible. The time was later reduced with the "faster" lenses such as the Petzval's portrait lens, the first mathematically calculated lens.

In 1849, Daguerreotype images photographed by the famous Russian Photographer Sergei Lvovich Levitsky (1819-1898) while on a mission to the Caucasus in 1843, were exhbited by the famous Parisian optician Chevalier at the Paris Exposition of the Second Republic as an advertisement of their lenses. Levitsky's use of the Chevalier lens which used two cemented double lenses improved the camera's focusing ability, thus reducing the time needed to capture an image for portraiture and landscape photography. Levitsky's Dageurreotypes would receive the Exposition's gold medal; the first time a prize of its kind had ever been awarded to a photograph.

The Daguerreotype was the Polaroid of the day, producing a single image which was not reproducible (unlike the Talbot process). Despite this drawback, millions of Daguerreotypes were produced. By 1851, the year of Daguerre's death, the Fox Talbot negative process was refined by the development of the wet collodion process, whereby a glass negative enabled a limitless number of sharp prints to be made. These developments made the Daguerreotype redundant and the process very soon disappeared.

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