Thu 20-Jun-13 04:52 AM | edited Thu 20-Jun-13 04:53 AM by JosephK
Sounds like things might be working as expected. AF-C is continuous focus; as you change the object under the chosen focus point during the recompose, the camera will refocus as the distance to the new object changes.
In AF-A, the camera picks AF-C or AF-S based on whatever algorithm it has. Personally, I don't see this as a good thing. You already know if your subject is static or moving; just pick the right mode to start with. It would seem that as you try to recompose in AF-A mode, the camera thinks your subject is moving and silently moves into AF-C mode.
---------+---------+---------+---------+---------+ Joseph K Seattle, WA, USA