WET PLATE COLLODION
Wet Plate Collodion
We have proudly served a diverse clientele, including amateur photographers, art students, and history enthusiasts. Our workshops have attracted participants from various backgrounds, each eager to learn about these unique processes. Our commitment to fostering creativity and preserving history resonates with individuals who appreciate the art of photography.
In 1851 the English sculptor and photographer Frederick Scott Archer published a process built around collodion — a syrupy solution of nitrocellulose (“guncotton”) in ether and alcohol — used to hold light-sensitive silver salts on a sheet of glass. Archer chose not to patent it, releasing the process for free public use, and within a few years it had all but ended the daguerreotype era: a collodion negative on glass could be printed on paper again and again, something no daguerreotype could ever do.
The process demanded speed. The plate had to be coated, sensitized, exposed, and developed while still wet — all within roughly fifteen minutes — which is why travelling wet-plate photographers hauled portable darkrooms, tents, and wagons to their subjects, including onto Crimean and American Civil War battlefields.
Two direct-positive variants turned the process into a household name rather than only a studio technique. The ambrotype (a term generally credited to the American patent-holder James Ambrose Cutting, 1854) backs a deliberately underexposed collodion negative on glass with black material, so the faint silver image reads as a positive. The tintype, or ferrotype (patented by Hamilton Smith in 1856), does the same on a sheet of black-lacquered iron — cheaper, unbreakable, and quick enough to make that it became the process of street photographers, fairground booths, and soldiers sending portraits home.
How it works
Pour a collodion solution containing dissolved iodide and bromide salts evenly across a clean glass or blackened metal plate, tilting it to coat the whole surface — this happens just minutes before exposure, under dim light.
Sensitize the still-wet plate by immersing it in a silver nitrate bath, which reacts with the iodide and bromide already in the collodion to form a light-sensitive silver salt within the film.
Load the dripping plate into a light-tight holder, carry it to the camera, and expose. Collodion is far more sensitive than daguerreotype chemistry, so exposures run from a couple of seconds in bright light to under a minute in duller conditions.
Return to the darkroom, or dark tent in the field, immediately and develop the image while the plate is still wet — before the collodion can dry and lose its sensitivity.
Fix the plate to clear the remaining unexposed silver, then wash, dry, and varnish it to protect the delicate emulsion underneath.
On glass backed in black, or on black-lacquered iron, the thin, underexposed image reads as a positive — an ambrotype or a tintype. On clear glass left unbacked, the same plate serves instead as a negative, ready to print multiple paper positives.