Sigma APO 50-150mm f/2.8 EX DC HSM

Transitioning quickly from one shot to the next using a variety of focal lengths—it’s one of the features I appreciate most in the new APO 50-150mm ƒ/2.8 EX DC HSM telephoto zoom lens from Sigma. One moment you can get down low to compose a close-up of a lizard and the next you can zoom in tight on a bird about to burst into flight 50 feet away. In addition to its quick response time, the Hyper Sonic Motor (HSM) autofocus is remarkably silent. And the manual focus override switch makes changing from one mode to the other simple, even while shooting.