Because it’s been raining and cold for weeks here I took the Sony A7 III with the Sigma MC-11 Adapter and the Sigma 180mm f\2.8 APO Macro EX DG HSM OS for Canon to a “butterfly conservatory” to get in some macro shooting.
This was a fairly challenging environment for the auto focus because the light level was low. What I found was that the autofocus works but it is far from fast and because it is a macro lens it can get lost in the focus wind up if the light level is low or the subject contrast is low. Several times I switched the lens to manual to reset it after it lost its mind. But as I said it was a fairly challenging lighting situation. My take on this is that the 180 mm Macro is an acceptable autofocus lens on the MC-11 but far from state of the art. The lens itself takes excellent macro and other photos. I am seriously thinking of getting it either in the Canon mount or possibly the amount for use with the LA-EA3. I’ll have to rent that mount version soon to check it out and see if it’s any better.
By the way, the turkey vulture wasn’t at the butterfly place. It was in a tree pretty far from my spot on a road side. It’s a pretty extreme crop so the autofocus was working well when the lens was used as a telephoto lens.