Daguerreotype.
1839-1860s
Louis-Jacques-Mandé
Daguerre (1787-1851) invented the first practical photographic process
in the late 1830's. His creation, the daguerreotype, involved coating a
copper plate with silver which was then sensitized with iodine vapor. This
now light-sensitive plate was exposed in a camera for several minutes.
After the exposure the plate was treated with mercury vapor, which yielded
a positive image on the plate. The image was then fixed with water (earlier)
or hyposulfite of soda (later). After 1840, gold chloride was used to intensify
the image.
Daguerreotypes
are unique. The only way to reproduce a daguerreotype was to photograph
an already existing plate. In addition, daguerreotypes were very fragile;
the image existing only on the thin coating of silver on the underlying
copper plate. Scratches in this coating caused irreparable damage, and
so daguerreotypes were often displayed in a case with a glass plate for
protection. Daguerreotypy was the most popular photographic process through
the mid 1850's. Well over 95% of all daguerreotypes were portraits.
Daguerreotypes
were expensive and each was unique. However they are quite easy to identify
and can be recognised by the mirrored surface. As the polished plate reflects
the light the image, which is in reverse, appears either negative or positive
as the viewing angle is changed. A plate which has been removed from its
original protective studio mounting will almost certainly be in very poor
condition.
A
Description of the Process -
prepared by The Daguerreian Society
View
how a Daguerreotype is made
View
Image of a Daguerreotype
View
component parts of a Daguerreotype