What Is Wet Plate Collodion?

First introduced by Frederick Scott Archer in 1851, the wet plate collodion process was the state of the art photographic process until about 1880, when manufactured dry plates came into practice. The term “wet plate” refers to the fact that the plate, whether of glass (making a positive ambrotype, or a negative) or metal (ferrotype) must be wet and not allowed to dry at any stage of the process. If the plate does dry at any point, all is lost. Therefore, it is absolutely necessary to work within close proximity of one’s darkroom, or to have a portable darkroom. The process is a challenging and dangerous one. A glass plate is first thoroughly cleaned and polished, and then collodion is flowed over the plate’s surface. In the darkroom, the plate is plunged into a solution of silver nitrate, and allowed to sensitize for 3 minutes. The plate is removed, allowed to drain for several seconds, and then placed into a special plate holder. The plate in its holder is then taken to the camera (for Brie, a 5x7 field camera), which has been previously composed and focused. After removing the darkslide, the lens cap is removed, exposing the plate anywhere from 1 second to several seconds, depending on the light. Then the plate is taken back to the darkroom, and developed in an acidic iron sulfate solution. Development is stopped with clean water, the plate is fixed in potassium cyanide, and then it is thoroughly washed. After it is dry, the plate is heated gently over a flame and coated with a varnish of gum sandarac and lavender oil. This is then allowed to set up by further heating over the flame. The wet plate collodion process can yield either a negative or a positive (ambrotype) image depending on the amount of iron sulfate in the developer. If creating an ambrotype, the back of the plate must be coated with a liquid asphaltum solution to create a black background on which to view the image. Because each plate is the final product, the ambrotype requires more than one sitting to obtain more than one image, and thus it is a one of kind work of art. Come into Castell Photography to view works in wet plate collodion, and Brie Castell's newest body of ambrotypes, "Ritual & Relic." Brie is also accepting commissions in wet plate collodion. 828.255.1188 info@castellphotography.com