Daguerreotype

Daguerreotype was the first publicly available photographic process, widely used from the 1830s to 1850s. "Daguerreotype" also refers to an image created through this process.

Invented by Louis Daguerre and introduced worldwide in 1839, the daguerreotype was almost completely superseded by 1856 with new, less expensive processes, such as the ambrotype (collodion process), that yield more readily viewable images. Since the late 20th century, some photographers interested in making artistic use of early photographic processes have revived the daguerreotype process.

To make the image, a daguerreotypist polished a sheet of silver-plated copper to a mirror finish; treated it with fumes that made its surface light-sensitive; exposed it in a camera for as long as was judged to be necessary, which could be as little as a few seconds for brightly sunlit subjects or much longer with less intense lighting; made the resulting latent image on it visible by fuming it with mercury vapor; removed its sensitivity to light by liquid chemical treatment; rinsed and dried it; and then sealed the easily marred result behind glass in a protective enclosure.

The image is on a mirror-like silver surface and will appear either positive or negative, depending on the angle at which it is viewed, how it is lit and whether a light or dark background is being reflected in the metal. The darkest areas of the image are simply bare silver; lighter areas have a microscopically fine light-scattering texture. The surface is very delicate, and even the lightest wiping can permanently scuff it. Some tarnish around the edges is normal.

Several types of antique photographs, most often ambrotypes and tintypes, but sometimes even old prints on paper, are commonly misidentified as daguerreotypes, especially if they are in the small, ornamented cases in which daguerreotypes made in the US and the UK were usually housed.