In the final photography scene, Jacoby and his accomplice are set up to take a picture of a burial tree. The developing tent is nowhere to be seen. As Jacoby stated earlier, he needed to develop each picture immediately after taking it, but that would be impossible in this instance.
When Chester looks in the camera, the image is upside-down (which is correct). However, it should also be reversed left-to-right (which it isn't).
Someone calls Jacoby's pictures tintypes (ferrotypes). Jacoby is actually making wet-plate photographs, a completely different process. (This is confirmed by his saying that the image must be developed before the plate dries.)
Just prior to Gart being killed, the string that guides the arrow can be seen against the dark jacket of Professor Jacoby. The hole in Gart's shirt was preexisting so as to run the string to the anchor on Gart's body pad and also because the hollow arrow tip would not have cut through the shirt's fabric.
The target for the arrow that hits Gart is obvious we he starts to turn toward the photographer. Just before and just after it hits him. There is even a hole in the shirt between two of the shirt buttons that look like the scene took more than one take to complete. They didn't bother to have a second shirt for a second take.
The quality of the picture of Miss Kitty is of far too high a quality for the times.