US Patent 7164462 Filming using rear-projection screen and image projector

A method for controlling a depth of field when filming a scene. A rear-projection screen behind a subject in a foreground is provided. An image is projected onto the rear-projection screen to act as a background for the scene. The scene is filmed including the foreground and the background. A varying degree of focus is applied to a plurality of objects in the image as a function of a degree of focus of each of the objects for an intended distance between each of the objects and the subject.