Difference between revisions of "Wet-collodion"
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* [http://www.cwreenactors.com/phorum/ Wet Plate Collodion Forum] | * [http://www.cwreenactors.com/phorum/ Wet Plate Collodion Forum] | ||
* [http://en.wikipedia.org/wiki/Collodion_process Wikipedia] | * [http://en.wikipedia.org/wiki/Collodion_process Wikipedia] | ||
+ | * [http://www.mhs.ox.ac.uk/cameras/index.htm?item7 Portable sensitizing tank for collodion plates] in the catalogue of an exhibition ''Cameras: the Technology of Photography'' at [http://www.mhs.ox.ac.uk/ Museum of the History of Science, Oxford] 20 May - 13 September 1997. |
Revision as of 22:36, 3 May 2011
wet-plate camera with brass lens made by Charles Louis Chevalier image by Roman Art (Image rights) |
Wet-Collodion is a negative-positive photographic process using potassium iodide dissolved with collodion - a solution of gun-cotton in ether. Gun-cotton is made by treating cotton wool with nitric acid, producing nitro-cellulose; nitro-cellulose was later used as a flexible film base.
The potassium iodide/collodion solution is spread onto glass plates, where the ether evaporates. Before the ether completely evaporates, the plates are sensitized in a bath of silver nitrate solution. Plates had to be exposed whilst still wet, so the plate preparation had to be done immediately before use; this meant that outside the studio, photographers had to carry a small tent with a supply of plates, sensitization bath and bottles of the solutions.
The process was invented in 1850, and published in 1851 by Frederick Scott Archer, although a Frenchman, Gustave Le Gray may have discovered the process at around the same time.
Links
- Wet Plate Collodion Forum
- Wikipedia
- Portable sensitizing tank for collodion plates in the catalogue of an exhibition Cameras: the Technology of Photography at Museum of the History of Science, Oxford 20 May - 13 September 1997.