The Autry Museum held a Civil War-era photographic demonstration by collodion plate artist Will Dunniway.
Although they said "space is limited" I got the impression they didn't turn anyone away because there were over 100 people crowding around on a Sunday morning.
Some of his images were on display:
Collodion Plate (Ambrotype) are reversed images (note the letters are backwards) exposed on a coated piece of glass. This glass negative, is the finished product and is made to look positive by giving it a black background.
It requires several steps. Collodion is poured onto a glass plate, covering the entire surface. In the Portable darkroom, the glass plate is dipped into a solution containing silver nitrate for about three minutes.
The plate is transferred into a light tight carrier which is placed into the camera. The camera does not have a shutter, just a lens cap which is removed to make the exposure. This can take 3-5 seconds (for people) or several minutes (still life/landscapes).
Adults are often placed in a brace to help hold them still.
Back in the darkroom, the exposed place is placed in developer solution, then rinsed and placed in a fixer solution.
Finally, it is washed, dried, and a coat of varnish is applied.
This process is blue sensitive which means blue comes out white. See above the subject is wearing blue, the green rod is the head brace. Will's wife assists him and is wearing a period costume.A Condensed History
Daguerreotypes (1839-1870) made on a delicate, fragile copper plate coated with silver. The plate was then sealed in a glass sandwich to form an image packet which was then placed into a small wooden case for protection.
Ambrotype (1854-1865) which was a collodion image made on a glass plate which would be varnished to help preserve the image. It was also placed in wooden cases.
Tintypes (1856-WWI) also known as melainotype or ferrotype, was a direct positive image on a thin sheet of metal that was coated with dark lacquer.
Kodak (1890-2000) came alone and opened the world of photography to everyone. His roll film camera would create negatives that would be printed onto paper.