A special effects shot developed in the early days of filmmaking. Used primarily for the illusion of riding in moving cars, trains, or stagecoaches. Previously filmed background footage is projected upon a transparent screen (outside the window). The actors sit in a specially designed vehicle where the front, sides, or back can be removed to show the actor with the moving landscape in the background.
A shot coordinated with another image created by Rear Projection, making the resulting picture look like a single simultaneous shot. A typical process shot shows the faces of two people riding in a car; behind them (as seen through the rear window) moves the usual traffic of a city street. The traffic has been added by rear projection, creating a process shot.