Image was taken without any cross shift, while image was taken from exactly the same place but with the camera turned on the tripod for a flatter perspective on the elevation. A simple cross shift movement was used to re-centre the image. Swinging or tilting the lens alters the plane of focus without changing the shape or position of the image, thereby controlling the depth of field. The swing movements possible on a view camera enable sharp focus to be achieved across the full depth of the elevation by altering the plane of focus. The mirror flips up, out of the way, a split second before the shutter is released. Because the distances between the lens and focusing screen, and between the lens and film are the same, the image that is sharply focused on the screen will be sharply focused on film.