1. A person who has the same physical properties of a particular actor, and takes their place during the lengthy setup of a scene. This allows the actor to prepare for the filming itself. Stand-ins are helpful in the initial processes of production.
Lighting setup can be a slow and tedious process; during this time the actor will often be somewhere else. Stand-ins allow the director of photography to light the set, the camera department to light and focus scenes. The director will often ask stand-ins to deliver the scene dialogue (“lines”) and walk through (“blocking”) the scenes to be filmed. In this way, a good stand-in can help speed up the day’s production and is a necessary and valuable cast member on a film.