thanks for the tip. what could you comment about its image quality? is it as sharp as the 15-85mm? cos the canon one i tested and it appears fine. much sharper than the ef50mm 1.8 wide open (i compared)
Bro check out the review of the Sigma 17-70mm f2.8-4.0 DC OS HSM here:
http://www.lenstip.com/223.11-Lens_review-Sigma_17-70_mm_f_2.8-4.0_DC_Macro_OS_HSM_Summary.html
this site has sample pics at the bottom, full jpeg file if u wanna check out the sharpness! Has a pic sample in each focal lengths so as to your question on sharpness!

they also have a review on the canon 15-85 on that side, but like me, they find it to expensive... Coz if u add lets say $100 to $200 to your budget, u can already get an "L" lense from buy n sell here at CS!
Happy shooting bro! Also, i still think 50mm f1.8 shoots sharper esp. in low light! Or maybe its just me!
