When the proper vertical balance is achieved, you can rotate the camera in any angle and it will stay at that position.
1. Rotate the tilt axis so that the lens is pointing upward.Then, loosen vertical adjustment thumbscrew, gently slide the camera mount crossbar forward and backward until the camera remains pointing upward when released.
2. Tighten the thumbscrew. Sometimes, the vertical balance could not be achieved, the front-back balance should be re-checked in this case.