Friday, May 26, 2017

Alternative Process : Wet Plate Collodion

James Weber

Collodion prints were invented in 1851 by Fredrick Scott Archer, and the primary subject for them was people. The print negatives were made on glass. There are other types, such as an Ambrotype, is the glass with a black backing. Another type is the Tintype, which is a positive image printed onto metal that became popular in the Civil War. The Wet Plate Collodion process is eight steps, 3 of them are cutting, deburring and cleaning the glass. Then you pour the mixture on the plate and sensitize it. Then put the plate in silver nitrate for 3-5 minutes and developing it for 15-20 seconds after you take it out. Lastly, you fix the plate with potassium cyanide and watch it change from a blue negative into a warmer ambrotype.


Wet Plate Collodion





Alternative Process : Cyanotype

Brian Young

In 1842 Sir John Herschel invented the cyanotype in 1842, it is the first permanent non-silver process. The 2 chemicals used are potassium ferricyanide and ferric ammonium citrate green, which you brush onto the paper. Then you expose it to the negative and process it in the sun. The picture really shows up when you wash it in cold water. The cyanotype became widely used in the late nineteenth century for engineering (blueprints).