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GLOSSARY OF PHOTOGRAPHIC TERMS

Albumen print

Invented by Louis Désiré Blanquart-Evrard of France in 1850, this process replaced salt prints for copying from photographic negatives. Thin paper soaked in a bath of egg whites and salt, offered a smoother surface than salted paper alone, and was capable of recording more accurate detail. A bath in silver nitrate solution sensitized the paper to light. Sunlight contact printed an image onto the albumen paper through a collodion glass negative.

Originally reddish brown in color, most albumen prints have faded over time to a yellowish brown tone. Image particles are suspended in the albumen layer on top of the paper instead of in the fibers of the paper itself. Until about 1890, albumen prints reigned as the prevalent process.

Ambrotype

An ambrotype is an underexposed (thus whitened), wet collodion negative, set against a dark background (usually paint, cloth or paper) to appear as a positive image. Ambrotypes sometimes superficially resemble daguerreotypes because they were placed in the same style cases. They are, however, an entirely different photographic process secured on a piece of glass as opposed to the piece of silvered copper plate used for a daguerreotype.

Iodized collodion poured on the glass formed a sticky coating, which was then sensitized with silver nitrate, and exposed in the camera while wet. The ambrotype remained a one of a kind image, just as the daguerreotype was a one of a kind image.

In 1852, Frederick Scott Archer introduced ambrotypes into England. By 1854, the process took hold in America, gradually eclipsing the daguerreotype. The ambrotype was less reflective than the daguerreotype and thus easier to view, but it usually captured less detail and less tonal range. Ambrotypes were easy to tint and cheaper to make and sell than daguerreotypes. By the mid 1860s, tintypes and carte de visites replaced the ambrotype.

Carte de visite

This visiting card style of photograph was a French invention, patented about 1854. In 1860, "Royal Album" carte de visite portraits of the royal family elevated the style into fashion.

Millions of cdv's were produced over the next fifteen years. In America, cdv's gained popularity during the Civil War because they were cheap, sturdy (for mailing), and available in multiple copies. Many individuals sat for their cdv portrait, but mass produced portraits of celebrities were also sold. Supposedly, more than 100,000 carte de visite photographs were produced and distributed of Abraham Lincoln alone.

The bottom or back of the cdv often advertized the photographer's name and address. Carte de visite's were usually collected in special albums designed to hold them. A typical cdv portrait was a head and shoulders or full length pose--usually an albumen photograph, but occasionally a salt print. The photograph was mounted on a stiff card measuring about 2 1/2 by 4 1/4 inches.

Collodion glass negative

Collodion was made from gun cotton (cotton soaked in nitric and sulfuric acid and dried) dissolved into a mixture of alcohol, ether, and potassium iodide. This syrupy mixture was poured onto clean glass plates. While still wet, the glass plate was sensitized in a solution of silver nitrate, and exposed in a camera. Fixed, washed, dried, and coated with protective varnish, the negative was then used to produce prints (salt or albumen) by contact printing in sunlight.

F. Scott Archer published the collodion process in 1851. The process was widely used until 1881.

Daguerreotype

The first practical photographic process invented by Louis Jacques Mandé Daguerre in 1839. A fine daguerreotype is an extremely beautiful, detailed image formed on the highly polished, silver coated surface of a copper metal plate. The silvered surface, sensitized in fumes of iodine, was placed in a camera for exposure. The plate was developed in mercury vapor.

No negative was involved, and the image produced on the plate appears as both negative and positive when turned in the light. The surface of a daguerreotype is extremely fragile, requiring protection behind mat and glass in folding, booklike cases of leather covered wood or plastic. To set off the daguerreotype, most cases also contain linings of dark velvet or silk. Daguerreotypes are one of a kind. Copies required additional exposures.

Aptly termed a "mirror with a memory" by Oliver Wendell Holmes, daguerreotypes were sometimes hand tinted with color to heighten realism. Gazing into the subtle realities of "presence" captured in a great daguerreotype can afford an unforgettable experience. No photographic reproduction equals actually viewing such an image.

Sizes of daguerreotypes were early standardized. A full or whole plate was the largest size ordinarily available. The full plate measured 6 1/2 by 8 1/2 inches, from which smaller sizes were derived. The half plate measured 4 1/4 by 5 1/2 inches. The quarter plate measured 3 1/4 by 4 1/4 inches. The sixth plate measured 2 3/4 by 3 1/4 inches. The ninth plate measured 2 by 2 1/2 inches.

Salt print

A sheet of paper sensitized in a solution of salt (sodium chloride) and then coated with silver nitrate on one side only. The salt combined with the silver nitrate to form light sensitive silver chloride. After drying, the paper was contact printed in sunlight through a glass or paper negative in a printing frame.

By 1860, albumen prints largely replaced salt prints. Confederate photographers briefly revived the salt print process, presumably after the Union blockade cut off chemicals or supplies needed for the albumen process.

Silver nitrate

Silver dissolved in nitric acid forms silver nitrate. This chemical reacts with salts containing chlorine, bromine or iodine to form light-sensitive silver halides.

Stereograph or Stereocard

Paired photographs of the same image which, when viewed through a stereoscope, appear as a single image in three dimension. There are stereo daguerreotypes and ambrotypes but most, called "card" stereographs were made of albumen prints set next to each other on a cardboard mount. A dual-lens camera made two exposures separated approximately as far apart as are human eyes.

In 1854, Frederick and William Langenheim issued the first American card series. Most stereographs date from the mid-1850s to about 1920. Viewing stereographs through the stereoscope was extremely popular parlor entertainment. No other form of photograph provides such a complete record of the world changing from agrarianism to a new industrial and urban way of life.

Tintype or Ferrotype

Invented in 1856 by Hamilton Smith, an Ohio professor of chemistry and physics, the tintype was an offshoot of the daguerreotype and ambrotype. As with the daguerreotype, the image was secured on a metal plate exposed in the camera, but the metal was iron instead of copper and it was lacquered with a black or brown japan varnish instead of being coated with silver. As with the glass plate of an ambrotype, the metal plate of a tintype was sensitized with collodion and silver nitrate before camera exposure. Until 1865, tintypes were housed in the same cases as daguerreotypes and ambrotypes.

The tintype's popularity expanded during the Civil War. Tintypes were easier to take and could better withstand vicissitudes of the mail. Tintypes remained popular until after 1900.