A straight line drawn across one or two vanishing points that marks the height at which the camera is positioned. Depending on the camera angle, the horizon line moves up or down within the frame, which is why it can be used to help to deduce the type of camera angle. If the horizon line slopes to one side, the camera is in a canted angle position. Changing positions of the horizon line and optical distortions, depending on different camera angles and heights.
