Britannica Sources used in this answer

Why did photographers using the wet collodion process need a portable darkroom?

Created from Britannica articles using AI. AI can make mistakes, so verify using Britannica articles.

Alfred Stieglitz: Child with Striped Dress (Younger Raab Child) — History of photography *Child with Striped Dress (Younger Raab Child)*, autochrome photograph by Alfred Stieglitz, 1907; in the Art Institute of Chicago.

Photographers using the wet-collodion process required a portable darkroom because the entire photographic procedure had to be completed while the plate remained wet.12

Invented by Frederick Scott Archer in 1851, the process required the photographer to coat a glass plate with collodion, sensitize it in a silver nitrate solution, expose it in the camera, and develop it immediately. If the collodion film were allowed to dry, it would become waterproof, preventing the necessary chemical reagents from penetrating the surface to develop or fix the image. Because these steps had to occur in rapid succession, photographers working in the field needed to carry a portable darkroom to prepare and process their plates on-site before the emulsion dried.132