I gave my 'Gift' PENTAX SF-7 an outing loaded with Kodak BW400CN film given to me by a Camera Club Mate who got it in a Car Boot Sale . HERE I did NOT 'Straighten ' the photo as I took it from Waist Level as a 'Candid' while walking past to see if the 'Auto-Focus' worked.
The answer Pete is Yes The auto focus works really well. I have the MZ7 part of a later series than the SF. I'll have to give this type of shot a try to see if my MZ7 works as well as in thius kind of situation as your SF7 does