I have been struggling to get really clear photos from my 70-200 with the 1.4xIII extender so I tried to dial in AFMA on the weekend. I know there will be some image degradation when you add an extender, but that is not what I am asking about. I tried to keep this as apples-to-apples as possible, test shots were done indoors, on a tripod, with 10 second delay timer & mirror lock up, using a remote cable release, IS turned off, so there should be no movement. But try as I might, I can't get the shots taken through the viewfinder to focus quite as sharp as live view. I used FoCal, and also did some shots on either side of the suggested AFMA setting, and the best I could come up with is shown, with a setting of -2. Am I missing something here, or is this about as good as I can expect?
These images are 100% crop, not adjusted at all, just converted from RAW to JPG and then cropped.
Larger, uncropped versions are https://www.dropbox.com/s/4za1f2452khry6l/5D3_3770.jpg
Thank you for your help.