What lens does the wet plate camera use? Can I use SLR lenses? Where can I get a lens like this? Is DIY okay?

It’s meaningless if you use the wet version to reach the image circle that the 135 SLR lens can cover. Generally, the wet version can be played up to 8*10, and the size of the image circle will depend on the lens you get. You don’t need to make your own fuselage. There are very old and large wooden machines in many second-hand stores. They were produced in a certain European country in 19XX. It doesn’t matter the brand or function, as long as it doesn’t leak light. If you buy a machine with a leather cavity, the leather cavity must not leak light. Fixed wooden boxes are more recommended for older machines. They have a simple structure and are easier to find for older machines. The lens you choose depends on your frame size. Most of the lenses above 8*10 are very old lenses, which can be as old as Topogon or Dagor. Pay attention to safety when applying the medicine. Substances such as collodion are particularly susceptible to fire. If you pursue quality when dispensing medicine, buy Sinopharm’s reagents. If you still don’t understand, just ask.