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 both vertical adjustment thumbscrews, gently slide the camera mount crossbar and the top bar forward and backward until the camera remains pointing upward when released.
2. Tighten the thumbscrews. Check the number markings on both vertical rods are the same. Sometimes, the vertical balance could not be achieved, the front-back balance should be rechecked in this case.