I was recently asked what the difference is between AFC (Continuous Auto Focus) and AF Tracking, both offered on Panasonic's current Lumix G series cameras? After contacting some low friends in high places ;-) I was able to get the raw data and create this explanation. I think this will be helpful to some of you. AFC (G Series Focus Mode Switch ) The camera focuses on a moving subject. If there is another moving subject that appears at same time, the camera may focus on the unintended subject. In the case of the LUMIX G series cameras, the camera’s priority logic focuses on the closer of the two moving subjects. The camera may focus on unintended subject, if the secondary subject appears in front of your primary subject. This function and behavior is a reality with both the phase difference AF and contrast AF AF tracking (offered on G Series cameras with touch focus control) The camera recognizes the selected subject and focuses in accordance with the movement of the subject. In the case of the LUMIX G series cameras, the camera distinguishes and recognizes the subject by the color (and contrast). So a possible scenario could be if the camera focuses on a green vehicle (with AF Tracking) and passes in the front of a tree. The camera may switch focus to the green leaves of the tree. This operation and behavior of the AF tracking feature is only experienced with the contrast AF system.