The Sigma 150-600mm f/5-6.3 DG OS HSM lens for Nikon is a hyper-telephoto lens designed for capturing distant subjects, whether you are interested in Wildlife Photography, Aerial Photography or Action Sports Photography. The 1.4x Teleconverter TC-1401 will offer an increased focal length of 1.4x. It offers full communication between the lens and camera and allows AF to operate at up to f/8.