Originally posted by normhead Thanks for your replies one and all. I guess I should have been more specific. My wife and I are working towards an exhibition of landscape and wildlife work. I own a DA*60-250 that is giving me better images than I see from other Canikon types living in the area and that I'm quite happy with. Before I broke down and bought the 60-250 I returned two Sigma 120-400's, they just weren't sharp enough 300-400mm, I can't tell you how much I wanted that lens to work out for me.
Anyway the canikon guys have some razor sharp long lens wildlife shots out there. I'm just trying to be capable of competing on an even playing field. My DA* 60-250 gets me an advantage as far as it goes. I haven't had it a full season yet, so who knows, maybe it will be enough... but I'm preparing for the eventuality that I'll probably need more reach.
Thanks for your suggestions.
out of curiosity, how do my "dirt cheap" 500mm shots compare with your expectations?
Note, I also shoot a sigma APO 70-200F2.8 EX (Non DG Non Macro) with 1.4x and 2x TCs.
I also find it excellent, as shown by the attached shots
about 10% of the K10D frame at ISO 1600 (who says the K10D can't do ISO 1600
Full frame resized only
about 50% crop out of K10D frame
Again same question about your expectations.
Note, many here have commented previously that the earliest Sigma (non DG) is the sharpest at 200mm. I kind og agree with that, which is why i have never upgraded it to a newer version