Hello - I'm an enthusiast photographer who is relatively new to shooting video, and I'm hoping to use my OMD EM5 to shoot a bunch of semi-professional looking videos that we will host on YouTube. My problem is that the auto focus is ruining the videos. The camera can't seem to keep the subject in focus, and the frame will go in and out of focus repeatedly during the course of the 5-20 minute videos. The camera is mounted on a tripod indoors and the subject of the videos is roughly 10 feet away, and is doing an exercise routine. As she moves, the camera loses focus and the result is incredibly distracting (and disappointing). Is there a setting or a particular lens that would be best for shooting video? Is manual focus something I should consider? I've tried AF and C-AF and they are both giving me poor results. I own the 14-42 kit lens, the Panasonic 25mm lens, the Oly 45mm lens, the 7-14mm panasonic wide angle lens....which is best for video?