Nikon 17-35mm f/2.8D ED-IF AF-S Super Wide Angle Zoom Nikkor Lens - International Version (No Warranty) Nikon's exclusive Silent Wave Motor for swift and quiet autofocus operation withthe current SLR's Two types of aspherical lens moulded-glass (two elements) and hybrid minimise distortion at the periphery Constant maximum aperture of f/2.8 at all focal lengths. Two ED (Extra-low Dispersion) glass elements minimise chromatic aberration, provide higher resolution and superior contrast High-performance Nikon Super Integrated Coating offers superior colour reproduction, while minimising ghost and flare