right
The
ambrotype process (from Greek
ambrotos, "immortal") or
amphitype is a
photographicPhotography is the process, activity and art of creating still or moving pictures by recording radiation on a sensitive medium, such as a photographic film, or an electronic sensor...
process that creates a positive photographic image on a sheet of glass using the wet plate
collodion processThe collodion process is an early photographic process, which was replaced at the end of the 19th century with dry plates - glass plates with a photographic emulsion of silver halides suspended in gelatin...
. In the United States, ambrotypes first came into use in the early 1850s. The wet plate collodion process was invented just a few years before that by
Frederick Scott ArcherFrederick Scott Archer invented the photographic collodion process which preceded the modern gelatin emulsion. He was born in Bishop's Stortford in the UK and is remembered mainly for this single achievement which greatly increased the accessibility of photography for the general public.Scott...
, but ambrotypes used the plate image as a positive, instead of a negative.
right
The
ambrotype process (from Greek
ambrotos, "immortal") or
amphitype is a
photographicPhotography is the process, activity and art of creating still or moving pictures by recording radiation on a sensitive medium, such as a photographic film, or an electronic sensor...
process that creates a positive photographic image on a sheet of glass using the wet plate
collodion processThe collodion process is an early photographic process, which was replaced at the end of the 19th century with dry plates - glass plates with a photographic emulsion of silver halides suspended in gelatin...
. In the United States, ambrotypes first came into use in the early 1850s. The wet plate collodion process was invented just a few years before that by
Frederick Scott ArcherFrederick Scott Archer invented the photographic collodion process which preceded the modern gelatin emulsion. He was born in Bishop's Stortford in the UK and is remembered mainly for this single achievement which greatly increased the accessibility of photography for the general public.Scott...
, but ambrotypes used the plate image as a positive, instead of a negative. In 1854,
James Ambrose CuttingJames Ambrose Cutting was a 19th century American photographer and inventor, sometimes called the inventor of the Ambrotype photographic process.He grew up in poverty on a farm in Havershill, NH...
of Boston took out several patents relating to the process and may be responsible for coining the term "ambrotype".
In the
United KingdomThe United Kingdom of Great Britain and Northern Ireland is a sovereign state located off the northwestern coast of continental Europe. It is an island country, spanning an archipelago including Great Britain, the northeastern part of Ireland, and many small islands...
it was called
collodion positive: one side of a very clean glass plate is covered with a thin layer of
collodionCollodion is a flammable, syrupy solution of pyroxylin in ether and alcohol, used as a surgical dressing or to hold dressings in place. When painted on the skin, collodion dries to form a flexible cellulose film...
, then dipped in a silver nitrate solution. The plate is exposed to the subject while still wet. (Exposure times vary from five to sixty seconds or more depending on the amount of available light.) The plate is then developed and fixed. The resulting negative, when viewed by reflected light against a black background, appears to be a positive image: the clear areas look black, and the exposed, opaque areas appear light. This effect is achieved by coating one side of the glass negative with black
varnishVarnish is a transparent, hard, protective finish or film primarily used in wood finishing but also for other materials. Varnish is traditionally a combination of a drying oil, a resin, and a thinner or solvent. Varnish finishes are usually glossy but may be designed to produce satin or semi-gloss...
. Either the emulsion side or the blank side can be covered with the varnish: when the blank side is blackened, the thickness of the glass adds a sense of depth to the image. In either case, another plate of glass is put over the fragile emulsion side to protect it, and the whole is mounted in a metal frame and kept in a protective case. In some instances the protective glass was cemented directly to the emulsion, generally with a
balsam resinBurseraceae is a moderately sized family of 17-18 genera and about 540 species of flowering plants. The actual numbers differ according to the time period in which a given source is written describing this family. The Burseraceae is also known as the Torchwood family, the frankincense and myrrh...
. This protected the image well but tended to make it darker.
The ambrotype was much less expensive to produce than the
daguerreotypeA daguerreotype is an early type of photograph, developed by Louis Daguerre, in which the image is exposed directly onto a mirror-polished surface of silver bearing a coating of silver halide particles deposited by iodine vapor. In later developments bromine and chlorine vapors were also used,...
, and it lacked the daguerreotype's shiny metallic surface, which some found unappealing. By the late 1850s, the ambrotype was overtaking the daguerreotype in popularity; by the mid-1860s, the ambrotype itself was supplanted by the
tintypeTintype, also melainotype and ferrotype, is a photograph made by creating a direct positive on a sheet of iron metal that is blackened by painting, laquering or enamelling and is used as a support for a collodion photographic emulsion....
and other processes.
Ambrotypes were often hand-tinted. Untinted ambrotypes are grayish-white and have less contrast and brilliance than daguerreotypes.
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