MTF over 90% on zoom for Canon @f8

[arith]

I cannot find MTF for this lens;

Tamron 17-50mm F2.8 XR Di II LD Asp Canon Mount

and I want one over 90% @f8 with similar range and up to 13.6mm (10lp solid and dashed close) or a prime less than or equal to 20mm with good flare performance.

I'm thinking long term here, I'm not going out and getting one tomorrow but would like to know alternatives to Canon.

[John C]

I think this is the lens you are referring to:
http://www.lenstip.com/18.1-Lens_rev...roduction.html
Seems like a fairly good lens.

[arith]

Good site, but I have a few concerns about the lens, chromatic aberration ect. Also it would be easier if I could just see an MTF chart although I can see a 50lp reduced chart never actually look beyond 20lp per mm. cheers