Having some fun with this new lens.
At first was not sure if the lens would hold up to standards of being sharp, hand holdable
and fast focus shooting birds on the wing.
Not being sure what to expect..
I also did some gull's in flight and the lens was faster than my 75-300f4.5 focusing on moving objects.
So far I am happy with it. Nice an sharp at both extreams..added a 2x wow! It just works.
#1 at 910 iso 200 1/320 f10 200mm f5.6

#2 iso 200 1/320 f10 400mm

A little out my area for subjects...but a good test.
#3 iso200 1/160 f16 800mm 2x teleconverter

ronny