The AF-S 600mm f/4G ED VR Lens from Nikon is a high performance fast super telephoto prime lens for Nikon F mount cameras. It is compatible with both FX- and DX-format DSLRs and provides 900mm focal length equivalence on DX-format cameras. It is a robust and durable lens incorporating a magnesium die-cast barrel and professional-grade dust and moisture sealing allows it to be used in more rugged situations. It is extraordinarily long reaching and is effective for drawing in distant subjects and serves well those involved in sports and wildlife photography as well as other ultra-telephoto applications.