This is a conversion lens that can be used for the DA Star 200mm.

This is a conversion lens that can be used for the DA Star 200mm. The brightness becomes two steps darker, but the focal length can be expanded by 2X. It keeps the superior delineation performance of the DA Star 200mm F2.8 ED (IF) SDM and can be used as a super telephoto lens for the 400mm F5.6 (as of APS-C format, 35mm film format equivalent: 600mm F5.6). In that case, the minimum shooting distance remains unchanged at 1.2m for enabling high-magnification closeup photography. The lens is focused using the manual focus.