I agree it is far from perfect. I shot today playing with a 5x5 pattern. I did notice you must set it into CA+F + TR. Made a mistake by not having it set with the +TR part.
I think I'll try and set the len's switch to 4 meters to Infinity, otherwise it spends a lot of time hunting for birds in flight against blue sky. Don't know if the Focus Limiter works with it yet either.
Seems if the green outline eventually lands on the eye when you fire, that is the best outcome to insure it is in focus. Otherwise it might miss.
I need to review my Fine Focus Adjustments as mine seemed to front focus a bit as metnioned by Angus Gibbons above. I too got a lot of tree branches in front of the bird. I don't know if it locks on the primary AF point and keeps it while zooming around on the field to others. If so, that's about 25 AF tuning spots to double check on (ugh!) for the 300mm f/4 or the 420mm with TC-1.4.
One BIF from today with new version 2.0. Seems I also need to set the time and date in the camera too since the update.
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