Overview

The Pentax smc DA* 300mm F4.0 ED (IF) SDM is a compact, weather-sealed prime lens praised for excellent sharpness from f/4, rivaling macro lenses. Distortion and vignetting are negligible, and chromatic aberrations are well controlled. Autofocus via SDM is reasonably fast but may struggle with fast-moving subjects. Build is all-metal and robust, surviving drops; the tripod mount is removable. It suits wildlife and close-up photographers needing a durable, sharp telephoto, though f/4 may limit action shots.