Lens review
2007-09-21
Sigma 50-150mm f/2.8 APO EX DC HSM
10. Autofocus
Sigma 50-150 mm is equipped with ultrasonic HSM (Hyper Sonic Motor) AF drive. No wonder autofocus works quick and quiet. Unfortunately, in this case weak point of most Sigmas was exposed - faulty cooperation with Canon dSLRs. On our Canon 20D the lens had really big front-focus, which is perfectly shown on the picture below.
