Wet Plate Collodion
A process in which a glass plate is coated with collodion, sensitised, exposed and developed while still wet.
In depth
Introduced in 1851, it combined the detail of the daguerreotype with the reproducibility of the calotype and dominated photography for thirty years. Everything had to happen within about fifteen minutes before the collodion dried, which meant carrying a darkroom into the field — the reason so many nineteenth-century expedition photographers travelled with wagons.
Examples in practice
A wet plate portrait requires the plate to be coated, exposed for several seconds and developed before it dries.