I just got this lens today and I'm trying to familiarize myself with it so excuse me if I ask dumb questions. There is a rotating ring near the body with aperature numbers on it, they range from 2.8 - 32. For some reason I have to keep it on 32 because if I switch to any other number my camera says "f/EE" for the aperature which I am taking to mean error. Is this normal behavior for this lens? In my macro photography I can't get an aperature wider than about 5.6 and I would really like to be able to get a bit wider than that for a softer focus. Can someone tell me what's up?