A lens control device which is capable of controlling lens positions such that an in-focus state of an object image can be maintained even when a variable power lens is positioned outside a normal zoom range from a wide-angle end to a telephoto end. A sun gear shaft may include a channel fluidly connected to a lubricating fluid reservoir through a bore in the sun gear shaft. The cryogenically cooled radiation shield device also includes a first inner conduit extending about the area to be shielded from radiation.