Alternative Processes

Wet Plate Collodion

Nadar (Gaspard Felix Tournachon)

The wet plate collodion process was invented by Fredrick Scott Archer. This process was primarily used for portraits. The wet plate collodion process involves using a glass photographic plate coated with iodized collodion (a syrupy solution of nitrocellulose in a mixture of alcohol and ether) and dipped in silver nitrate solution. Once the print has been exposed to light and has had time to dry, it will create the final product.

Cyanotype

Anna Atkins

The cyanotype process was created by Sir John Herschel. The first person to ever use this was Anna Atkins and she used this process for botanicals. The cyanotype process involves brushing the chemicals potassium ferricyanide and ferric ammonium citrate on paper, exposing it to the negative and then processing the photo in the sun. But after the photo has been exposed ti the sun, the photo must rinsed in cold water. The cold water will produce the final result, leaving the photo with a blue background and white print. 

Gum Bichromate

Hugo Henneberg

Mungo Ponton was the first to discover the gum bichromate process. This process involves the use of colloids (gelatin and gum arabic). Once these two ingredients are mixed with a pigment and sensitized it with chromium salts, it will create a light sensitive emulsion. The print will then be put in a dark room to let the emulsion dry so that when exposed to the sun, it will darken the emulsion. The print will then be put in water to create the end result.