This has been n issue among Turkish Pentaxians since long time. I know some Pentaxians changed to Canon because of Ornito Photography. I wonder whether K-5 will be an naswer for this question. This afternoon I've heard a bird singing in my garden. This reminded me this question and I urged to get my new K-5 in my hand. First thing what I can say is about AF peformance. I can say Af performance will be anough for ornito photography. I made shots with different ISO levels to test high ISO levels. Here are the results for your intervention ;
By the way is there anybody who can tell me the species of this bird?
F/6.7, shutter speed 1/640, ISO 200, Focal Lenght 500mm
F/9 , shutter speed 1/8000 , ISO 3200, Focal Lenght 500mm
F/11 , shutter speed 1/8000 , ISO 6400, Focal Lenght 500mm