A technique used to fit a widescreen image on a narrow aspect ratio video system, accomplished by cropping the sides of the picture.  The un-cropped area is panned from side to side occasionally to follow the subject of the program, or to show otherwise hidden parts of the scene.  This technique is commonly used to prepare filmed movies for playback on a standard definition television screen (4:3 aspect ratio).  It is even necessary to prepare movies for widescreen television playback, as the 16:9 aspect screen has a more narrow aspect ratio than most movies.