Image motion compensation can be done by many methods such as exposure control, swinging camera in mount, moving the film, moving the lens, and by rotating mirrors. In figure A, the film is moved at the same speed at which the image moves on the stationary film. This results in sharp image of point on the ground. The direction flight at the speed of f·v/h where f is the focal length, v the aircraft speed, and h is the height. In figure B, the lens is moved in the opposite direction of flight at the rate of f·v/h.
A movement intentionally imparted to film at such a rate as to compensate for the forward motion of an air or space vehicle when photographing ground objects. It is an act of synchronizing the target image with the recorder.