Last night I did some interviews for a church project. Since it wasn't incredibly critical, I tried something I've wanted to try for a while. That is, I set my GH3 on continuous auto focus with the focus recognizing and focusing on faces. That way I could just relax and ask my questions during the interview instead of constantly stopping to check focus.
It worked really well, and I think I will do it this way from now on. Focus was razor sharp throughout the interviews. Leaning in or out...no problem. I will have no problem doing it this way in the future.
This was with an Olympus 45mm lens set to f1.8, so the depth of field was very shallow.