When a person walks or runs, each footstep sends a sizable jolt through the body. For the most part, you don't register these shocks visually, because the brain automatically adjusts the information coming from the eyes; it smooths out the disorienting motion when forming the visual image that the conscious mind is actually aware of.
Some cameras have a built-in adjustment mechanism to compensate for shaking motion, but it doesn't come close to the natural stabilization system in the human brain. The camera will still record a lot of the motion from the camera operator's steps.
Even when an operator is standing still, the camera may pick up a lot of jarring motion. It's so easy to pivot the camera that even a light push in any direction can translate to a considerable jump in the film or video image.
Don't get us wrong. The jolts and shakes of hand-held footage work well for certain scenes -- an unsettling chase in a horror movie (think "Evil Dead") or a bare-bones documentary, and some directors intentionally employ shaky cam, as "The Blair Witch Project" and "Cloverfield" did. But for the most part, filmmakers have shied away from hand-held cinematography. When a scene called for the camera to move, the crew attached it to a dolly, a wheeled platform that rides on a track or smooth floor. Dollies work great for a wide range of shots, but they have certain limitations. You can't use them on stairs, for example, and they are hard to navigate around obstacles. It is also extremely difficult to set them up on rough terrain.
In the early 1970s, a commercial director and producer named Garrett Brown began working on alternative stabilizing systems to get around these limitations. Brown wanted to build a highly portable device that would isolate the camera from the operator, as well as improve the camera's balance, to minimize shakes and shocks.
In 1973, Brown realized his goals with a revolutionary but remarkably simple machine. "Brown's Stabilizer," later renamed Steadicam. Larger models steady a camera using only three major elements:
- An articulated, iso-elastic arm
- A specialized sled that holds the camera equipment
- A supportive vest
In the diagram, you can see how these elements come together. The camera, along with a battery and a monitor, are positioned on the sled. The sled is attached to the articulated arm, which is attached to the vest. The arm and vest configuration works to isolate the camera from the body of the cameraman. The sled's job is to provide optimum balance for the camera.
In the next few sections, we'll look at these elements to see how they virtually eliminate the shocks and jolts of hand-held camera operation.