I unofficially photographed an event, a marquee lunch, last week using a Sigma 50mm f1.4 on my D7000. The lens was set at f2 and manual focus so that I could selectively focus on individuals and throw background and foreground out of focus, and the success rate was high. I felt much more in control than with autofocus. However, with the added bother of having to zoom, I don't know. I suspect it would be asking a lot.