Louis Jacques Mandé Daguerra
Louis Jacques Mandé Daguerra (1787 -1851) was a flamboyant Frenchman full of enthusiasm and energy and had become famous in the world of Parisian theatre for his inventive use of special effects, artistry and stage decoration. At sixteen he became a student of Degotis, who was a creator of stage settings at the Paris Opera.
In 1824, Daguerre was elevated to Knight of the Legion of Honor. At the same time he was also experimenting with his own photographic process. He learned how to use a camera obscura with Pierre Prevost (1766-1823) who used it to prepare his huge trompe-l’œil canvases. Joseph Nicephore Niépce’s camera obscura was probably made by the famous Paris opticians Charles and Vincent Chevalier, who made possible the contact between Daquerra and Niepce.
In December 1827, Daguerre met Niépce in Paris on his way to England. The two men got along together. Niépce was fascinated by the Diorama. Daguerre too had had the idea to capture the images of the camera obscura. For this purpose, he put phosphorescent powders at the back of his camera obscura. The image projected on this powder remained visible for a few hours then slowly faded away. The two men met again on Niépce‘s return from England in February 1828.
They started afterward to trade ideas by mail and in 1829, Niépce suggested to Daguerre to create a partnership to contribute to the development of the invention of Heliography. The contract was signed in December 1829; Daguerre put a lot of work on the process. He brought an important contribution since the two men invented in1832 a new process: the physautotype. In 1839, some years after his Niépce’s had passed away, Daguerra announced an effective process of photography, which also produced a direct positive image and which he had been working on since 1835.
The process involved coating copper plates with polished silver. These were then sensitised by exposure to iodine vapour. The vapour reacted with the silver to form the light sensitive compound, silver iodine. Exposure times were very slow upwards of 15 minutes, even in bright sunlight, but eventually this was improved by fine tuning. The development process was apparently an accidental discovery. The story goes that Daguerra put some previously exposed plates, which were not showing an image, into a storage cupboard for later use. When he took them out again they displayed the image he had first exposed them to. He eventually concluded that mercury vapour, rising from a broken thermometer, had developed them. This was the first time the concept of developing a latent image had entered the science of photography. It was to be the backbone of all future research.
Daguerra’s method of developing plates included an air tight box so they could be safely exposed to the lethal fumes rising from the heated mercury. After this treatment, the mercury formed a white amalgam where the plate had seen more exposure. Daguerra used a salt solution to remove the unexposed silver iodine, thus revealing the shadows of the picture. He later incorporated the astronomer and chemist John Herschel’s Hypo (sodium thiosulfate) Formula, which would dissolve silver salts.
The Daguerreotype process was highly successful despite its great limitations. The main drawback copies could only be made by taking more than one exposure, or by re-photographing the subject, which would have taken another 30 minutes of sitting in the same pose, however the images produced were pin- sharp.
In 1839, Daguerre and Niepce’s son sold the rights for the daguerreotype to the French government and published a booklet describing the process. The daguerreotype gained popularity quickly; by 1850, there were over seventy daguerreotype studios in New York City alone.