My eyesight is getting somewhat rusty when it comes to manually focus my good ol' Nikkor 400mm f/3.5, so I bought an AF Sigma 400mm f/5.6. While the AF is quite slow, if I prefocus it works and I'm quite impressed with the image quality, considering how cheap you can get one.
This shot was done in less than ideal lightning conditions, but the action between the two kind of compensates for it to my eyes. think I should sharpen it a little bit more, and I'm not happy with the processing either, so I would love to hear oppinions and ideas on the matter!
Nikon D200, ISO400, 1/750, f/8
Sigma 400mm f/5.6 APO Macro
Nice behaviour and comp, Patricio. You asked for some processing suggestions so here's my 2c. The birds look underexposed and some +EC at capture would have helped but would have lost the nice sky BG. I have increased the contrast and saturation in the sky to increase the impact of that while dodging the birds to brighten them up. UNfortunately working on the small jpg file this has caused a lot of posterisation and there is significant jpg artifact but it gives the idea.