I don't think you can manually focus with that housing. There is only one ring gear and that is on the zoom ring (talking about the zoom lenses). Stated anothre way, the housing has only one control knob in the front. Thus, you could use it to control the zoom ring or the manual focus ring but not both. Now, having said that, if you use a single focal lenght lens (e.g. macro lens) I presume you could control the manual focus ring. Maybe that was Oly's thinking in not providing two ring gear controls on the front of the housing. Bottom line, you are at the mercy of auto focus. Good news is that a 9mm lens (18mm equivalent) at F 5.6 has an enormous depth of field and just about everything is going to be in focus.