Why is this method of photography called wet-plate?
The plate is coated with a gelatinous substance called collodion (used as a liquid bandage in the mid-1800s). Different chemicals such as bromides and iodides are mixed into the collodion. The plate is dipped into a bath of silver nitrate for 3 minutes, making the collodion surface light-sensitive.
After the plate is removed from the silver bath it is placed wet in a film holder. The photograph must be taken while the plate remains wet, which means there is only a 3-5 minute window of time to make the image, then develop it on site. I have a darkbox and a cargo trailer that can I use to develop images on location.
When was wet-plate photography used?
Frederick Scott Archer developed the process in 1851, and it became a popular and inexpensive method of making pictures. When the War between the States broke out, soldiers wanted their images struck to be mailed home and the tintypes proved to be the perfect medium.
Wet-plate photography was replaced by dry plates in the 1880s. With this new technology, photographs could be made at any time, then developed later. George Eastman developed a coating method for dry plates and used it to quit his job at a bank and found Kodak.
What is the difference between a tintype and an ambrotype?
With a tintype, the image is made on a plate of metal. In the 1800s, a thin sheet of iron covered with asphalt was used. No tin was actually used, but it's believed that tintype got its name from the use of tin snips to cut the metal plate. I use aluminum pre-coated plate because of the convenience.
An ambrotype is made on glass, and it initially appears as a negative. When a black surface is placed behind the plate, the negative appears as a positive. It is a more delicate picture.
A negative can be obtained by making a longer exposure, and a print can be made either by placing the negative on a sheet of light-sensitive paper or in an enlarger. I have an 8x10 enlarger that can make huge prints, but I limit the size to 16x20.
What is a daguerrotype?
That was the predecessor to the wet-plate photographs. The images are stunning, but the process is expensive, extremely finicky and dangerous. Chemicals like mercury are used and the material for each picture costs $40 or more. I don't, and won't, do dags.
With the convenience of digital photography, why bother with a process that's so outdated, cumbersome, time-intensive and finicky?
I'm glad you asked that question, although part of me says if you have to ask, you'll never know the answer. I got into wet-plate because after 3 decades of working with film and then digital, I missed the surprise element of photography. I had by no means mastered film, but I knew with the ability I have, I could predict how the final image would appear. Digital, while an excellent tool, seldom surprises. But wet-plate photography almost guarantees surprises. Serendipitous elements creep into each picture. For example, the image below from a wet-plate negative was almost lost when the emulsion started peeling away after removal from the silver bath, and it left a nice jagged edge, which contrasts nicely with the blurry background of trees.