Here are some images taken last evening during magic hour until just after sunset at the Trexler Nature Preserve Environmental Center with my tripod mounted A7r and my Minolta CLE MC 40mm f2 M-Rokkor lens. All images processed in LR5.6.
And some with the OM200mm f4 with 2x tele extender...
The combo is okay, but pushes the ISO up too much (lose a bit of detail). Not sure if it's better than the 200mm f4 cropped or not. Seems pretty good in the sun. Incredibly small 400mm equivalent. No real issues with CA at f5.6 or f8. f4 didn't look very good. Not too bad for a really old design.
And some with the OM200mm f4 with 2x tele extender...
The combo is okay, but pushes the ISO up too much (lose a bit of detail). Not sure if it's better than the 200mm f4 cropped or not. Seems pretty good in the sun. Incredibly small 400mm equivalent. No real issues with CA at f5.6 or f8. f4 didn't look very good. Not too bad for a really old design.