Testing the Tamron 10-24mm f/3.5-4.5 DI II Lens

ISO 12233 Resolution Chart Crops have been added to the Tamron 10-24mm f/3.5-4.5 DI II Lens Review page.
 
The Tamron 10-24mm f/3.5-4.5 DI II Lens and I are off to a rocky start. The first copy backfocused at all focal lengths. The second copy backfocused at 24mm. And by backfocusing, I'm talking about the lens focusing behind the subject by an unacceptable amount (not just a tiny distance) on both a 50D and a Rebel T2i. The third purchased-retail lens appears to be focusing accurately.
 
I have added ISO 12233 Chart results from the last two lenses (select the specific lens results to view using the drop-down box) - I was hoping the wide open results from the first-tested lens were an anomaly, but ... they apparently were not. You will not want to use this lens wide open very often.