180-degree line
Also known as: axis of action, the 180 rule
The imaginary line between two subjects that a camera stays on one side of, so that screen direction stays consistent from shot to shot.
Updated
What it means
Draw a line through the action. Keep every camera on one side of it and a rider travelling left to right keeps travelling left to right, however the shots are arranged.
Cross the line and direction flips. The same rider now appears to turn around, and a viewer spends the next moment working out what happened instead of watching. Nothing in the picture explains the reversal.
It is the oldest rule in editing and the easiest one to break with action cameras, because a Chest mount and a trailside tripod rarely sit on the same side of anything.
How it works in practice
Multi-camera sessions need the decision made at the start. One side of the trail becomes the camera side, and every fixed angle goes there even when the other side has better light.
Aerials complicate it immediately. A drone flying across a rider crosses the line as a matter of course, so a Tracking shot from the air usually goes between sections rather than inside a run.
Where the line has been crossed, a neutral shot rescues the cut. A head-on angle or a Cutaway belongs to neither side and lets direction reset without a visible jump.
What to watch out for
Automatic assembly does not see direction. A selection built on motion and quality can place two shots of the same rider travelling opposite ways, and each is a good clip on its own.
Point of view material is exempt and feels like it should not be. POV footage has no screen direction to break, which is why a Helmet mount run cuts against almost anything.
Mirrored exports are the invisible version. A clip flipped horizontally for a Vertical video (9:16) crop reverses direction silently, and the rule is broken by an export setting rather than by a camera position.
How RawClip handles it
Shot selection is driven by what happens in a clip rather than by screen geometry, so direction is something to watch for in the result. Choosing one camera side while filming is the reliable way to keep an assembled sequence reading cleanly.