Usually, if you want to use a supertelephoto prime lens for things like wildlife or sports photography, you have to use first-party options. However, Sigma offers a rare exception to that rule, the 500mm f/4 DG OS HSM Sports, and it offers that combination of extra-long focal length and wide aperture sought after by many professionals at a significantly more affordable price. Can it match pace with the likes of Canon and Nikon? This great video review takes a look at the lens to answer that question.