The Pentax SMCP-DA* 50-135mm f/2.8 ED (IF) SDM Autofocus Lens is a high-quality telephoto zoom lens that is designed for exclusive use with Pentax digital SLR cameras. It offers a focal length that is equivalent (in 35mm format) from 75mm to 202mm. This wide coverage is ideal for a variety of telephoto applications, including portraiture, sports and scenery.