Wimberley

This accessory will be featured inIssue #4ofThe Video Journaldue out in April, 2002.
Don't Gamble‚ Get a Gimbal
If you are considering the use of a really large telephoto lens‚ a 400mm f/2.8, 500mm f/4 or a 600mm f/4‚ then a ballhead (even the largest) simply won't do. You need a gimbal head. 
This has everything to do with gravity. With a ballhead the lens / camera combination rests on a point‚ the ball. If the camera is tilted upwards or downwards, such as when following a bird in flight, or even when simply panning to reposition, the whole assembly will tilt forward or back under its own weight. This is inherently unstable and can lead to a big expensive lens ending face-down in the dirt.
With a gimbal mount the entire weight ishungrather than balanced, and it consequently remains extremely stable. A 15lb camera / lens combination can be panned and tilted with a single finger, and because the horizontal and vertical axis are separate they can be locked independently.
Illus...