Collodion process
（重定向自Wet Collodion Process）
![An old deteriorated dry plate featuring Theodore Roosevelt is similar to a wet plate image but has substantial differences.](/Images/godic/202502/20/Theodore_Roosevelt_on_broken_glass3401.jpg")
![A portable photography studio in 19th century Ireland. The wet collodion process sometimes gave rise to portable darkrooms, as photographic images needed to be developed while the plate was still wet.](/Images/godic/202502/20/Micklethwaite_Portable_studio3401.jpg")
![Anonymous](/Images/godic/202502/20/1860_Anonyme_Un_vétéran_et_sa_femme_Ambrotype3401.jpg")
The collodion process is an early photographic process, said to have been invented, almost simultaneously, by Frederick Scott Archer and Gustave Le Gray in about 1851. During the subsequent decades of its popularity, many photographers and experimenters refined or varied the process. By the end of the 1850s it had almost entirely replaced the first practical photographic process, the daguerreotype.