Tamron 17-50 f/2.8 vs Canon 17-40 f/4 L

Tamron 17-50 2.8 vs Canon 18-55 3.5-5.6 (kit lens)

Original pics by BenSeese posted here:

http://www.flickr.com/photos/benseese/with/144189644/

 

 

Canon 17-40 4L @ 17mm f/5.6
Tamron 17-50 2.8 @ 17mm f/5.6