An optical system mount arrangement includes a stop, a mount for an optical element, and an electromagnet. The mount has a first position and a second position, the mount abutting the stop in the first position and the mount spaced apart from the stop in the second position. The electromagnet is fixed relative to the stop and is arranged to exert a holding force when the mount is in the first position. Optical systems, vehicles carrying optical systems, and methods moving optical elements in optical systems are also described.