Quantaray 135-400mm f/4.5-5.6 APO is a medium to long-range telephoto lens. The 135-400mm covers the most frequently used focal lengths. Incorporating 5-group zoom system achieves sharp, high contrast results all the way across the zoom range. The lens features special coating to render the highest degree of color balance while minimizing ghosting and flare caused by digital image sensors. Chromatic aberration are also compensated for with the 135-400 zoom lens. Three SLD glass elements removes secondary spectra effect normally associated with telephotos. The rear focus system keeps the front lens from rotating, giving you easier use of polarizing filters. It's built-in tripod mount eliminates vibration during shutter release. The lens is ideal for sports, nature, wildlife and many other photographic applications requiring a telephoto range.