Just curious which of these two someone would buy and why you would choose one over the other? I realize the focal length difference but do not think that would be as big of an issue. I am looking for closer prime ( I already have the 85mm USM but find that many times its hard to get back enough and would like something just slightly wider. ) I like the fact that the Tamron has macro which is a great selling point and it can also be a good portrait lense. However, would you rather skip the macro and have a wider f1.4 lense over f2.0. So far, I am thinking that f2.0 will not be much different than the f1.8 85mm lense in terms of depth of field. I am happy with the f1.8 depth of field so I think I would be happy with the f2.0. One more caveat, the Canon USM 50mm would be atleast $100 less. Let me know your thoughts. Thanks.