THE QED OF OLD PICTURES
Antique photography (both the wet- and dry-plate processes) is a wondrous and often mysterious method of capturing the results of photon interaction with light-sensitive chemicals. To assist in de-mystifying this arcane practice of seizing the past, we offer the following definitions, measurements, observations and palimpsests of broken glass. Should we be remiss in not covering a detail or topic you’d like to know more about, just email us. No appropriate, relevant or intriguing question will be ignored.
Albumen print: Albumen prints are a variety of photographic paper print in which a finely divided silver and gold image is dispersed in a matrix of egg white. Such prints constitute by far the largest category of objects in 19th century photographic collections. Albumen paper became the most widely used photographic printing material about 1855, and remained so until 1895; it did not disappear completely from photographic practice until the 1920’s. (re: James M. Reilly
Research Associate, School of Photographic Arts and Sciences, Rochester Institute of Technology)
Boudoir print. Usual image size: 8.5 inches by 5.25 inches, with some slight variations.
Cabinet print. Common image size: 5.5 inches by 4 inches, with mount approximately 6.5 inches by 4.25 inches. Fractional variations occurred. From 1865 on.
Cabinet size prints. Print: 8 inches by 6 inches; usually mounted in albums. Circa 1865 on.
Cartes de visite. Image size: 3.5 inches by 2.25 inches; mounted on cards approximately 4.125 inches by 2.4 inches. Circa 1853 and on. Size made it convenient to expose between 4 – 10 images on same glass plate.
Chromolithograph. Lithography process using various stones with different inks applied so that when photographic paper is rolled over them the illusion of a “color” scene is portrayed.
Dry-plate process. Negative development process avoiding the use of aqueous solutions.
Glass-plate negative. A glass plate used as a substrate for light-sensitive chemical emulsions.
Imperial print. Image size: 9.875 inches by 6.875 inches.
Mammoth print. Image size: 18 inches by 22 inches.
Photochrome. Another name for a chromolithograph (see above).
Stereopticon. A photographic mount exhibiting two almost exact photographic images, slightly differing to create, when viewed through bifocal lenses, the illusion of three dimensions.
Wet-plate process. A negative development process using aqueous solutions (chemical emulsions) spread over a glass-plate substrate.
Largest size: 18 inches by 22 inches (mammoth print size; largest size of albumen paper available from France in the 1850s). Various sizes used as well as accommodating cameras.
Don’t be left out in the cold.