Combining the reach, speed, and optical quality of a super-telephoto prime with the versatility of a zoom, the Sigma 300-600mm f/4 DG OS Sports Lens is a well-rounded workhorse built for photographing sports, wildlife, and other distant action subjects. Combining a constant f/4 maximum aperture with quick AF, robust image stabilization, and a durable design, this impressive lens can easily replace a series of telephoto primes without sacrificing on weight or speed.