Did You Know: The Wet-Collodion Process
"A Veteran And His Wife" - unknown photographer
In 1851 F. Scott Archer of England made public his wet-collodion process, in which he used a glass plate coated with collodion as a base for light-sensitive silver halides. His procedure, requiring seven steps, was only slightly less complicated than the daguerreotype process, but it was considerably less expensive. It also produced a negative that was much sharper than that of the calotype method. Soon the wet-collodion process had supplanted both the older techniques as the most widely used process of photography.
A major inconvenience of the wet-collodion method was the fact that the plate was light-sensitive only as long as it remained wet; after it dried it lost its sensitivity. Thus plates had to be used almost immediately after preparation. Since these plates could not be prepared and stockpiled in advance, a portable darkroom, in the form of a tent, wagon, or railway car, for instance, had to accompany the camera wherever it went.