Lead Room

A moving subject needs somewhere to go. Space ahead of them tells the audience the movement continues past the edge of the frame, and the shot feels like travel rather than a person pinned to a wall.

Take the space away and the meaning flips. A runner crowded against the edge they are running toward reads as trapped, which is a real effect and a different shot.

Put more of the frame in front of the subject than behind. A common working split is roughly two thirds ahead and one third behind, and the faster the movement, the more space goes in front.

The camera holds that ratio while it pans or tracks, so the subject sits off centre for the length of the move rather than drifting toward the middle.

The direction of travel decides which side is open. A subject moving left needs the left of the frame clear, which means composing them on the right third.

Use it on any subject that moves across the frame: walking, running, driving, riding. It is the default, and a viewer notices its absence immediately.

Break it deliberately when a character is closed in. Short siding a moving subject is a strong effect, and it only works if the rest of the sequence gave them room.

Look space is the same idea applied to a gaze rather than movement. Lead room is about motion. A person standing still and looking left needs look space, not lead room.

Short siding is the deliberate reverse of both. If the subject is crowded against the edge they move toward, you are short siding on purpose.

The model centres the moving subject, which leaves equal space either side and kills the sense of travel. Say the space ahead is open and state the direction of movement.

The second failure is space on the wrong side. Naming the direction twice helps: moving to the left, with the left of the frame open.