The language of photography - Glossary of Photographic Processes

A photographic process popularized by James Ambrose Cutting in 1854. An ambrotype is a negative on a glass plate with whitish tones. When displayed against a black background, the image appears as a positive.

A brand name for the first emulsion papers manufactured in 1884 by the Liesegang company in Düsseldorf. This name came to be used to refer to papers that darken directly when exposed to gelatin (citrate paper) or collodion (cellloid paper).

A process for color photography. Introduced in 1907 by the Lumière Brothers, the autochrome plate is a slide consisting of a layer of potato starch dyed violet, orange, and green, covered with a black-and-white emulsion. The silver grains more or less mask certain colored starches, and the colors are thus reproduced through additive synthesis. Between 1929 and 1955, the Lumière company produced a version of its autochrome plate on flexible media: film sheets (Filmcolor, 1929–1954) and later film reels (Lumicolor, 1931–1952).

A photographic process based on the sensitivity of certain iron complexes, which are transformed into colored compounds when exposed to light. The resulting photograph is blue. This process, developed by John Herschel in 1842, is inexpensive and easy to carry out.

A photographic process that was popular between 1839 and 1855. The image is unique and produced on a copper plate coated with a layer of silver.

A positive photograph viewed by holding it up to the light or by projection. Produced since the 1850s using photographic plates made of albumin, collodion, or gelatin, they were used as magic lantern slides for projection. The term “slide” is closely associated with chromogenic color film technology, particularly Kodachrome, which was introduced in 1936. It became extremely popular among amateur photographers in the 1950s and 1960s in the 24 x 36 mm format.

A positive photographic image produced using the wet collodion process on a blackened metal plate.

A photomechanical reproduction process introduced by W. B. Woodbury in 1864. The image, consisting of a mixture of gelatin and carbon black, is produced using a lead matrix.

Contact printing of all images on a small- or medium-format film. If this process is performed using enlargement, it is preferable to use the term “enlarged contact sheet.”

In 1947, physicist Edwin Herbert Land introduced the first black-and-white instant film, named “Polaroid film” after his company. In 1963, the “Polacolor 1” color film was released, and the company went on to develop new versions of it over the years. Polaroid retained its market monopoly until the 1980s.

"Business card" portrait: a small-format portrait photograph (6 x 10 cm), popularized in 1854 by the Parisian photographer André Adolphe Eugène. He took four to eight exposures on a single plate, which was then printed on albumen paper. The print was cut out and mounted on cardboard.

In the 1880s, the photographic industry introduced developable papers: gelatin-silver bromide papers, which are still in use today, and silver chloride papers—known as “Gaslight” papers because they were exposed under the artificial light of gas lamps. The advantage of these papers lies in their speed of printing: unlike the direct blackening process, printing requires only a brief exposure to light and is achieved after chemical development (in a developer bath).

A process based on gelatin, pigments, and chromium salts, introduced by Alphonse Louis Poitevin in 1855, which produces particularly stable images.

The advent of chromogenic color prints followed a few years after the introduction of chromogenic color slides. The first color negative film was introduced by Agfa in 1939, followed by Kodak in 1942, but it wasn’t until the 1970s that color prints began to gain popularity. A chromogenic color print consists of at least three superimposed layers, colored yellow, magenta, and cyan, respectively. The dyes are synthesized during development, which is why this process is called chromogenic development.

A photographic printing process used between 1839 and 1850. The image was produced by direct blackening, then toned and fixed.