« on: May 01, 2013, 10:30:30 AM »
Can I attach Canon 1.4x III and 2.0x III extenders to my Canon 70-200 f/2.8 IS II USM at the same time and still get AF at 560mm f/8, or is this crazy talk?
Also I do a lot of Live View focusing for my landscape work, and always have the focus mode in the contrast detect "Live" mode (not "Quick" or "Face" modes) and it often switches inexplicably to the "Face" mode on it's own. I don't know if they are the correct mode names as I don't have the camera in front of me. It's a real "phenomenon" though - phenomenally annoying as it means I can't move the focus rectangle to where it needs to be! Anyone else get that?
Do you by chance have orientation base focus set? I don't know if/how that function might effect the live view focus mode, if at all, but it's worth considering. Another thing to consider is if you are using one of the custom modes (C1, C2, C3), it could be changing you focus mode, when you switch to or from these settings.