What are the types of manual camera racks?

Manual bucky stand is a kind of camera holder which is manually operated on the film box of the camera holder. It needs to adjust the rise and fall of the film holder manually.
There are also two types of manual camera racks: fixed and mobile. Mobile camera holders are fixed and mobile. Fixed manual camera racks mounts the camera holder on a flat hard ground 180 cm away from the ball tube to make the vertical center of the camera box coincide with the center of the ball tube. After correct adjustment, the camera holder aligns the four through-hole centers of 8.5 at the bottom of the column of the device, and installs four M 8 expansion screws by electric hammer, then tightens them.