History
Gustave Le Gray first theorized about the collodion process, publishing a method in 1850 that was "theoretical at best", but Frederick Scott Archer was credited with the invention of the process, which he created in 1848 and published in 1851. During the subsequent decades, many photographers and experimenters refined or varied the process. By the end of the 1860s, it had almost entirely replaced the first-announced photographic process, the daguerreotype. During the 1870s, the collodion process was largely replaced by gelatin dry plates—glass plates with a photographic emulsion of silver halides suspended in gelatin. Invented by Dr. Richard Leach Maddox in 1871, dry gelatin emulsion was not only more convenient, but it could also be made much more sensitive, greatly reducing exposure times. This marked the beginning of the modern era of photography. One collodion process, the tintype, was in limited use for casual portraiture by some itinerant and amusement park photographers as late as the 1930s, and the wet plate collodion process was still in use in the printing industry in the 1960s for line and tone work, mostly printed material involving black type against a white background because, in large volumes, it was much cheaper than gelatin film.21st century
The wet plate collodion process has undergone a revival as a historical technique in the twenty-first century. There are several practicing