[bigwhitemao]

if price are same , which one you want

[yingtu]

i buy 20-35mm

[fever20d]

so, if you are using 1.6X DSLR, you have sacrificed the wide angle

[FM2FM2]

yes 17-40mm is more wide

[riverg]

The wideness:
17mm if 1.6x = 27mm; 20mm will be 32mm. 5mm difference is huge.

The Aperture
f/2.80 vs f/4.0 -but in wide angle 90%+ chance i'll use f/8 and below so unless you want something special on the f/2.8

The Quality:
dont have 20-35mm but 17-40mm is really GOOD. If anyother can share their experienc on the former...

thanks.

[FM2FM2]

tks a lot! very details and professional