I have no experience with a Vision Blue, but I bought a used one from Adorama. The pan and tilt lock knobs don't do much. Gentle pressure on the pan bar can move the head on either axis. Can anyone tell me if this is normal? I've searched the web and the only thing I saw was one B&H review with a guy saying his doesn't lock. The question is how loose should it be? Mine is very loose. I can tilt and pan my C100 with 24-70mm with very little effort with the lock knobs tightened all the way. Thanks!