Head Tracking

The camera locks to the subject's head, so the head is the one still thing on screen and the world swings around it. Every turn the person makes becomes a movement of the entire background.

It turns a look into an event. When somebody glances left and the whole room slides right, the audience feels the turn rather than observing it.

The camera is fixed relative to the head, either on a rig carried by the performer or built in post. The head stays at the same size and angle in frame from the first frame to the last.

The background does everything. It has to swing, tilt and shift with each movement, and the strength of that swing is the measure of how well the lock reads.

Wide lenses exaggerate it. The nearer the lens and the wider the angle, the more violently the background travels for the same amount of head movement.

Use it on disorientation, intoxication and panic, and on any moment where a character's perception has come loose from the room.

Do not run it long. The effect is physical, and a viewer will feel it the way they feel a boat.

A SnorriCam rigs to the torso, so the frame holds the whole upper body and the swing comes from walking and from the shoulders.

Head tracking locks to the head alone, so a turn of the neck moves the world even when the body is still. If the background moves when only the eyes and head turn, it is head tracking.

The model returns a plain close-up with a steady background, because a still background is the easier picture. Say the background swings with every turn of the head.

The second failure is a head that drifts in frame. Say the head stays fixed at the same size and position, and that the motion belongs entirely to what is behind it.