Sigma APO 800mm f/5.6 EX DG HSM - Canon EF, Nikon F, Sigma SA Mount

The Sigma 800mm f/5.6 EX DG HSM is a super-telephoto prime lens designed for professional wildlife and sports photography. It features two Extraordinary Low Dispersion (ELD) glass elements to minimise chromatic aberration and a Hyper Sonic Motor (HSM) for quiet, high-speed autofocus. The internal focusing system ensures the lens length remains constant during operation, while the rotating drop-in filter holder at the rear accommodates 46mm filters. When inspecting a used copy, check the condition of the internal optics for dust or haze, particularly given the large front element. The matte 'EX' finish is prone to peeling or marking, so external wear is common. SDS technicians verify the autofocus motor is responsive and silent, and ensure the tripod collar rotates smoothly and locks securely. The rear drop-in filter holder should be present and undamaged.