There seems to be some confusion and miscommunications about S-AF, C-AF and C-AF TRacking modes. Partly because Olympus has changed the concepts from the 4/3 to the m4/3s cameras. Let's see if we can put this in a big nutshell. S-AF - Locks focus once and stays there. Good for stationary subjects or locking focusing and reframing. Because of the speed of the S-AF you can also lock focus just before your intended moment and then relock focus as you capture the moment want to capture. Anticipation of the moment is everything when focusing by this method. C-AF - The camera continuously refocuses locking onto whatever you have under the selected AF target. If the subject moves and the camera does not, the camera will lock focus on whatever it sees under your selected AF target. If something moves between you and the subject the camera may very well lock onto the moving item. For C-AF it is important to keep your AF Target on your subject! C-AF+TR - Locks focus on the subject under the selected AF target. If the subject moves the camera will try to follow the subject and keep refocusing on it, as long as you keep the subject within the viewfinder and fairly close to your selected AF Target. This provides you some leeway in not having to keep your explicit AF Target on the subject. C-AF+TR is ideally intended for where your subjects move quickly in unexpected directions. If you can anticpate and follow your subjects then S-AF or C-AF are better focusing modes for use. C-AF and C_AF+Tracking can be interrupted by something passing between you and the subject, in which case the camera may (probably will) lock focus on the something passing between you and the subject, unless you have something other than Off set for C-AF lock. C-AF lock - determines how long the camera should try and stay focused on the item under the AF Target of your choice, if something was to interfere with the initial lock. Since C-AF lock is set to Off by default, the camera will jump to anything it perceives you want to focus on. So if something moves between you and your intended subject, and if the camera captures that in one of the continuous focus moments, the camera will refocus on that new target. You can negate the speed with which C-AF and C-AF+TR jumps to new targets by setting C-AF Lock to Low, Normal, and High. I have played very little with m4/3s lens, C-AF and C-AF Tracking but was very disappointed when trying to use 4/3 lenses on the E-M1. I can say with 4/3s lenses you want to pick the highest contrast vertical element you can lock onto with good light. High contrast lighting does not help. It seemed as if at the C-AF Low setting the focus would change to a new subject slower than with C-AF lock set OFF, and as I moved to Normal and then High settings the camera would tolerate longer periods before changing to a new subject. But I had so many issues with the camera locking focus with the 4/3s lenses I am not 100% sure of this. I can tell you a great place to practice is a carousel or a busy highway. Start from further away and then move closer. Your positive or negative experince with C-AF and C-AF+TR will greatly be influenced by your level of experince. We also need to consider Release priority as it partly determines how well C-AF shots turn out. If the camera is set to Rls Priority (Custom Menu C) Off, then the camera must have locked focus before allowing the shutter to fire. Which initially sound sensible, but can be extremely irritating! If Rls Priority is set to ON, then the shutter can be released before the camera has locked focus. The premise here is that the camera focuses so quickly and/or the camera is already in the process of locking focus that between the time you press the shutter button and the shutter fires - focus will be locked! You can have different Release Priority settings for S-AF and C-AF. By default Release Priority for S-AF is set Off and for C-AF it is set to On.