Hi, I'm shooting a lip dub video in a few days, using my GY-HM100. I'll have to use autofocus, and I'm worried about how well this will do when moving around (the whole video is one shot of people coming into and out of view while the cameraman (me) moves around). Would using a smaller aperture help improve focus? Any other tips on how I can get the best possible results? I'm gonna be using a tripod as a stand-in steadycam, and I'm hoping to use the smoothcam filter, although I'm not sure if this will work for long clips.