I can send you some 6MP JPEG samples from the Sigma across the aperture
range used in mid-long distance. I don't have any samples shot up
close unfortunately.
I don't think it's a bad lens, not at all! At 2.8 it exhibited very
good sharpness and detail, surprising me somewhat. If the performance
wider open is good is up to one's taste, I guess. It wasn't quite to
mine taste, but YMMV.
As somebody mentioned, the 1.8 aperture is benefit in focusing
manually.
All depends how it compares to the Pentax FA or A, which I think
several people here have used with IstD. As I found the real speed
more like 2.3, I would not mind having the smaller lens. But all my
"tests" of it were also a matter of taste. As usual, YMMV ;-) Also
mind, I was comparing between Sigma and a Nikkor 20mm ;-)
Best would be to if you were able to try them both side by side...
Good light!
fra
