Ok, you guys can check is here on the Pbase,look this canon xti photos with Tamron 200-500mm:
http://www.pbase.com/bmullen/dunlins
or:
http://www.pbase.com/bmullen/shorebirdfavorites
and see with Nikon D200 example:
http://www.pbase.com/emcphotoart/inbox&page=4
And it is just one of the 100. Every sigma lens , like 100-300mm dg f4, with canon, 20d, 30d, amazing, with nikon d200 (more expensive)
is awfull!
Not sharp, i don't understand. Sigma tamron can't build a lens for nikon? Or just a canon cameras much better? I want to sell my fuji s3, because except portrai photos is suck, but i have no idea what will be a choice?
Nikon d200? or canon d5? 30d? Please help i have 2 grant for camera.Thank you!