Filming & Production
Camera cage
Also called: cage, rig cage
A cage wraps the camera in an aluminium skeleton covered in quarter-inch and three-eighths-inch threads, plus cold shoes and NATO rails. The camera on its own gives you one mounting point on top and one underneath. That runs out the moment you want a shotgun microphone and a monitor at the same time.
It also protects the body and gives you something to grip that is not the lens barrel. The costs are weight and bulk. Cages are machined for a specific camera model, so fit matters more than brand.