At the other end of the bellows, the "rear standard" is a frame that holds a ground glass plate, used for focusing and composing the image before exposure—and is replaced by a holder containing the light-sensitive film, plate, or image sensor for exposure. The front and rear standards can move in various ways relative to each other, unlike most other camera types. Whereas most cameras today control only the distance of the plane of focus from the camera, the view camera can also provide control over the orientation of the plane of focus, and perspective control. The camera is usually used on a tripod or other support.