Randy, did you take this through the glass window as on my monitor it looks a bit soft. I know I have a 1986 Nikon 300 2.8 and with a tamaron or Kenco 2X it's like there is nothing in the way but I think that is true of all F2.8 prime lenses. I have stacked the 2X and 1.4 on my old one and used a window mount and it did very well for such an old piece of glass. As a matter of fact I have three Nikon lens that are F2.8 and the 80 to 200 D mount is very very sharp with a 2X. Much better than my 70 to 200 VRG.
thx Rich, i just sold my bigma, it's not a bad lens but i am spoiled by primes....the sigma 300/2.8 is a fine lens and may get me to not get the nikon altho the vr might be nice for these little birds...Great Randy. I love my Sigma. I was a bit apprehensive after the disappointment of the Bigma, but they really make a nice, reasonably priced telephoto. Wish I could afford the Nikon glass, but that's not to be. Very nice work.