Pentax Lens SMC-DA 300mm, f/4.0, macro

SDM focusing, fast and quiet; Quick-Shift Focus System; Dirt-repellent SP coating; Seals against dust and moisture; Special optical ED glass and the PENTAX SP coating ensure very good contrast performance, consistent sharpness up to the edges, and particularly clear reproduction of fine details in the smc PENTAX-DA* 300 mm F4 ED [IF] SDM. Not only is this lens top-notch optically, but it is also excellently crafted mechanically. An ultrasonic motor in the lens provides a quiet and fast autofocus drive. In the DA* series, the lens is sealed against dust and moisture, which significantly contributes to the robustness of the camera system. For the coating of the front lenses, PENTAX uses special fluoride compounds, known as SP - "Super Protect" technology. This involves applying a special coating to the front lens. This nano-technology protects the front lens from dust, fingerprints, or greasy residues. If necessary, such contaminants can be easily removed. The PENTAX "Quick-Shift Focus System" allows photographers to adjust the focus after automatic sharpness has been achieved. This enables direct manual fine-tuning of the focus at any time without having to turn off the autofocus. The SDM system is only compatible with corresponding cameras; all other PENTAX DSLR cameras use the conventional body-side AF drive for focusing.