Covering a versatile array of wide-angle focal lengths, this is a flexible zoom ideal for landscape, cityscape, and interior photography. Its constant f/4 maximum aperture maintains consistent illumination throughout the zoom range and suits working in a variety of lighting conditions. The optical design contains three aspherical elements and two extra-low dispersion elements, which greatly reduce distortion and aberrations for a high degree of sharpness, clarity, and accurate rendering. A Nano Crystal Coat has also been applied to control flare and ghosting for greater contrast and color accuracy in harsh lighting and backlit conditions. Additionally, this lens also sports a Silent Wave Motor for fast and accurate autofocus along with VR II image stabilization to minimize the appearance of camera shake by 2.5 stops.