The Lure Of The Collodion Process

Pouring Collodion

An ether-rich liquid is poured onto a sheet of glass, and deliberately flowed to the edges... Thus begins the process of making collodion film from scratch.

Collodion requires an on-site darkroom to produce hand-sensitized plates one at a time, where you will be mixing flammable and poisonous chemicals, mastering hand skills, and facing an extensive learning curve. Why then, in the age of digital convenience and despite all these obstacles, has the wet-plate collodion process captured the attention of thousands of photographers and artists?

Collodion is to photography what watercolor is to painting -- fast, yet requiring exquisite manipulation. Each step of the process requires dexterity and quick decisions based on observation. While this presents certain challenges it also offers a very satisfying experience for the visual artist. The experience is seductive, but results are what matter. Artists are drawn to collodion for the combined effect of long exposure, ultra fine silver particles, limited color sensitivity and unlimited opportunities to celebrate the evidence of a hand-made object. Most practitioners, however, have yet to discover that this process offers even more...


First formulated in 1846, collodion was, and still is, used as a medical dressing. It is made from cotton soaked in nitric and sulfuric acids that is thoroughly washed and dried, then dissolved in ether and alcohol.

Collodion pouring into bottle
Excess collodion is poured back into the bottle. From The Wet-Collodion Process, S&O archive

When allowed to dry, collodion leaves a clear, thin, tough flexible coating. In 1851, Frederick Scott Archer suggested it was a perfect vehicle to hold light sensitive chemicals on glass for making negatives. Also called "cellulose nitrate," it is similar to the base used later for making the first flexible film.

W.M. Rossetti, 1865, by J.M.Cameron
W.M. Rossetti, 1865, by J.M.Cameron
Courtesy of George Eastman House,
International Museum of Photography and Film
19th c. example of "unskillfullness."

Making a Wet-collodion Negative

Collodion, containing small amounts of iodides and bromides, is poured onto a scrupulously clean piece of clear glass to produce an even coating. The collodion is allowed to flow to all four corners of the plate, and care must be taken not to create ridges that would show in the final negative. (see W.M. Rossetti, 1865, by Julia Margaret Cameron and 19th c. example of "unskillfullness.") The excess is poured off the plate and back into the bottle.

Coated Plate on Dipper
Coated Plate on Dipper
Sensitized Plate
Sensitized Plate

Before the ether and alcohol evaporate from the collodion, the plate is taken to the darkroom (under red or deep amber light) and dipped into a solution of silver nitrate, where it remains for a few minutes. At this time the silver nitrate bonds with the iodides and bromides in the collodion to make light-sensitive silver halides on and just under the surface of the collodion. While the plate is in the silver nitrate "bath," the camera is set up and focused on the subject.

The light-sensitive plate is placed into a light-proof holder attached to the camera. The plate is wet and silver nitrate droplets are present on the surface of the plate during the exposure. A "dark slide" is removed to expose the plate to the inside of the camera. Exposure is made by removing the lens cap. It can take approximately 20 seconds to 5 minutes to make the proper exposure for a wet-plate negative, depending on the age of the collodion, type of lens used, and the quality of light on the subject.

NEXT: Developing the Plate