Thank you for your response!
ISO was fairly high...can't remember exactly what it was but in some cases it could have been as high as 3200. I understand stepping down to f/4 but I've read many posts where folks say they're shooting at f/2.8. What's the point of a lens capable of f/2.8 when Im going to have to step down to f/4 to get better results. Your help is certainly appreciated!
I'd hate to say it (since I too have this lens), but ther version 2 of this lens would not find you having to "step down" to f/4 to be sharp. Used a friends recently, and i'm seriously jealous now.... although, at times I found it a little "too sharp" if there is such a thing, for my tast... or maybe it was just that the bokeh was not as pleasing... great lens overall, I wouldn't complain if i owned it