An Opteka High Definition 500mm preset telephoto lens is fully automatic and incorporates not only computer optical design, but also the latest optical multi-coating techniques. The process of multi-coating assures virtually flare free photographs even under adverse lighting conditions resulting in crisp, high contrast pictures. Preset Lenses are designed to retain a full range of exposure, automation and metering capabilities of the cameras on which they are mounted. This lens is great for nature and sports photography. The amazing power of this lens gives you the equivalent of looking through a pair of 10x power binoculars. It has a manual preset diaphragm, a rotating tripod mounting collar and a soft lens pouch. Advances in high-index / low-dispersion optical glasses, new barrel materials, and exotic anti-reflection coatings, along with the latest in computer-aided-design / computer-aided-manufacturing, are combined to produce lenses of unprecedented quality. Diamond-cut from crystal-clear, water-white optical glass, Opteka lenses are ground and polished to a precise precision. Opteka lenses put more creative control where it belongs - in your hands.