Tom - You are exactly right. The Sigma 150mm macro has a three-position focusing limiter switch to try and cut down on the hunting for focus. Under normal lighting for portraiture, I don't have a problem with the AF, but there are cicrumstances where it hunts. Its sharpness and overall IQ is what sets it apart, though. Ditto the 85 1.8 - and it does have fast and accurate AF - I often use it for indoor basketball. It's a very very versatile lens with little if any shortcomings (I can't think of any at the moment...)


Rob