Action occurring outside frame boundaries — tension builds from what the viewer doesn't see. Hitchcock fundamental, economical editing device.
The space outside the frame becomes a psychological weapon. You film an actress nervously looking at a door — but the door itself is in the off-space. The audience fills this void with fear, anticipation, sometimes relief. Hitchcock perfected this: tension arises not from what is shown, but from what remains hidden. The off-space is not a compositional error, but a deliberate dramaturgical decision, completed by editing and sound.
On set, you work with off-space by controlling gaze, movement, and sound. An actor looks to the left — the viewer's eye immediately becomes interested in what is happening to the left, outside the frame. You use this attention direction very deliberately: a hand enters from the right, the body follows with a delay, or not at all. Sound design significantly enhances the effect — footsteps approach from off-screen, get louder, stop abruptly. In editing, off-space works through sequence: a close-up of a face, cut to an empty wall, cut to something unexpected. The viewer's imagination works much harder than what you give them.
Practically: use off-space not by accident, but as a design element. An object at the edge of the frame, half-obscured, magnetically draws the gaze there — work with it, not against it. In dialogues, you can leave the other person off-screen, showing only the reaction. This intensifies any conversation many times over. Off-space works differently in documentaries: here you create space for editing, for what the viewer must combine themselves. Off-space achieves its greatest effect where sound and image deliberately diverge — this creates a productive confusion that is more emotional than any explicit shot.
Off-space works closely with editing — see also editing rhythm and suggestive editing. Without off-space, visual storytelling would be half as rich.