On my T3i I'm using a Sigma 17-70 F/2.8-4
I would like to replace it with a Sigma 17-50 F/2.8
Both have image stabilization, only difference is constant F/2.8 on the 17-50, and slightly shorter zoom which I'm fine with.
While I want a constant F/2.8 I'd prefer to improve image quality also, can anyone tell if this lens produces better quality images? I've heard both sides to this so not sure.