Sporgon said:Many review sources found that the Tamron 85 SP suffered from focus shift and that could be a big practical difference between that and the Canon lens. I don't think Dustin mentions it in his review though, so I presume he didn't find it an issue during his very practical review methods, but others certainly did.
On the back of Dustin's advice on the accuracy of these latest Tamron's AF I bought the 45 SP and it's an interesting and quite versatile lens, with no FS. I find that the vast majority of people do not want portraits where just one eye is in focus, and so when close I want smaller apertures; focus shift is something I just can't tolerate.
I know Bryan kind of drilled the Tamron 85 VC over focus shift, but I've owned one since release and never actually found it to be an issue in real world shooting. It's actually the most accurately focusing third party lens I've ever used.