« on: May 16, 2013, 01:38:20 PM »
A little help with a qualifier:
I recently rented a 5D III for the purpose of examining the F8 focus with a 100-400 when paired with a 1.4 III tc.
Subjectively, it worked well. The af was not perceptibly slower than "normal" in decent light. The picture quality was good but was affected. Because of some bad weather and a personal emergency, I was unable to use Reikan's focal to really dial it in. Overall, I would not buy a 5D III for the F8 but it certainly is useful. Btw, the 5D III was very impressive with its autofocus but I am sure you already know that.
I normally shoot, birds mostly, with a 7D.