This high zoom ratio for digital SLR cameras and capable of covering a broad range of focal lengths from 50mm standard to 500mm ultra telephoto optimized. In addition, the new super coating on each glass surface produces superb color reproduction while reducing glare and lens ghosting.This four pieces of SLD (Special Low Dispersion) glass for excellent correction of chromatic aberration throughout the zoom includes range.This also has on a Zoom Lock device Elim