One Selected Focus Point Expanded to Surrounding Points
A compromise between using all 45-points and using a single point is using a single focus point expanded to surrounding points via custom function III-8 (see below). This mode allows surrounding focus points to assist the selected focus point in achieving initial focus and also allows the camera to shift from the chosen point to any one of the six available surrounding points if the camera detects that the subject has moved from the selected point to one of those surrounding points. Similar to using all 45-points, initial focus must be locked in with the manually selected point to tell the camera on what it should be focusing, and, if the subject wanders beyond this smaller circle of surrounding points, focus will be lost. I like to use this option for much of my shooting because it gives me a bit of room for error if I am not successful in keeping the focus point on the subject. However, if the background is busy or if the subject is filling only a very tiny portion of the frame, this option can result in the surrounding points locking onto something other than the intended subject, and switching to a single focus point is likely to yield better results.
