I had a little play today with a Teleplus SHQ 1.7x TC on the DA*300. So 300 x 1.7 = 510mm (x 1.5 + 765mm)
Not a great combination as you have to disable the SDM or you can't get focus lock.
Begs the question as to why the hell it locks on screwdrive but not SDM.
Any way, here are some of the results.
Superb Fairy-wren, resized only.
Welcome Swallow, resized only (and only just caught, many missed).
Black-shouldered Kite 100% crop.
What it looked like through the viewfinder.
A bit closer. 100% crop.
Waiting for another try. 100% crop.
Little Eagle. Resized only.