The first practicable photographic process, called the daguerreotype, was invented by Louis Jacques Mandé Daguerre based on research conducted jointly with Nicéphore Niépce. It forms a finely detailed image on a copper plate coated with a thin layer of silver, which can be viewed as a positive or a negative depending on the angle viewed.
The daguerreotype was a huge commercial success, dominating the market for photographic processes until the early 1850s, when it began to be supplanted by collodion negatives.
Producing a daguerreotype is a long and painstaking process involving a series of steps. First, the manufacturer applies the silver coating to the plate. After the silver layer is meticulously polished and buffed, the plate is sensitized with iodine vapors. It is now ready for exposure; the exposure time may vary from several minutes to just a few seconds, depending on the lighting conditions and whether other chemicals were added to accelerate the process. Next, the latent image was developed using mercury vapor. The plate itself, which was originally stabilized with table salt, was immersed in sodium thiosulfate starting in 1841 to fix the image, and then rinsed. Finally, it was gilded if applicable, washed, and dried.
Because the silver-coated plates were extremely fragile, daguerreotypists learned right from the start to protect their images by placing them under glass, in decorated frames or cases, which are important elements used to authenticate and date these works.
Some contemporary photographers and artists have adapted the daguerreotype technique to their work, including Patrick Bailly-Maître-Grand, Chuck Close, Adam Fuss,
Mark Kessell, Irving Pobboravsky, and Jerry Spagnoli.
Visual glossary of photographic techniques
© ARCP / Mairie de Paris, 2013