I acquired this end goal in July, after testing it on vacation, I noticed that the autofocus too often behaved randomly, even on series whose composition and yet changed settings ... It's really frustrating especially that the sharpness is excellent when an update correctly. In low light it's even worse, yet it is the interest of having an opening 2.8! So I exchanged for another copy and then re-disappointment, AF was worse this time with a permanent frontfocus ranging from 5 to 10 depending on the focal ... a galley! I had the opportunity to purchase a nice promo on amazon today the latter not exite and the goal is sold 100 euros more expensive. So I wonder if it was not a bad batch ...
Fortunately the service of Amazon's top and I was able to smoothly return the refund. I would dream of that goal ... flawless!