The Daguerreotype process was the first publicly available photographic method of obtaining a permanent positive image. Its invention was announced on 19th August 1839.
The needed light-sensitive element in this process are silver halides developed on a pure silver surface which is polished to a mirror finish. The sensitized plate is then exposed in a camera and the resulting latent image on it is made visible by fuming it with mercury vapour. The image consists of microscopic particles of silver amalgam produced by the condensation of mercury vapour in places with photolytically separated silver. The unexposed halides are washed away during the fixing process.
The process of image making distinguishes Daguerreotypes from all other commonly used photographic processes. It produces unique, remarkably detailed, one-of-a-kind photographic images which are essentially non-multipliable.