Viewfinders - Text 10
The camera operator could place the lens selected for the next shot in front of this eyepiece, frame and focus, and then rotate the turret by 180º to bring the lens in front of the gate. This viewfinder was even equipped with a slot that could hold the masks commonly used at the time so that the camera operator could have a preview of the effect produced.
This ingenious system had two significant drawbacks. First, it was impossible to look through the taking lens while shooting. Second, it produced a parallax effect, which could be especially problematic when filming objects or subjects placed near the camera.
The Mitchell camera designed by John E. Leonard and marketed in 1921 made it possible to avoid the parallax effect by placing the turret on the front of an L-shaped base.