Optimized for DSLRs and compatible with film SLR cameras, the smc PENTAX-D FA 100mm f/2.8 WR Macro Lens is constructed with an aluminum housing and 6 weather seals (thus the WR designation) so you can shoot in almost any environment without risking internal damage to the lens. Optical elements are treated with the Pentax Super Protect multi-layer coating to lower surface reflection, reduce ultraviolet rays, and deliver clear, high-contrast images. Plus, the configurations of its optical elements produce crisp, sharp images with no flare and ghosting. It also features a "Quick Shift" focusing system which allows you to easily switch between manual and AF modes.