Like many modern macro lenses, Sigma’s full-frame compatible 105mm works equally well as a fast telephoto prime. The f/2.8 aperture enables quick shutter speeds even under dull lighting, while the fast ring-type ultrasonic AF system is good for tracking action. To speed up AF in tricky conditions, there’s also a three-position range limiter, with which you can select just the short or long focus range, either side of 0.5m.