Sigma APO 70-210mm f/2.8

Great lens The lens is sharp, but a bit heavy. If you are used to the Canon lenses, it takes a little bit tof getting used to, due to the focal length adjustment ring is outside of the focus adjustment ring, Other than that, I love the lens.

Sigma 70-200 mm DG OS HSM Sport lens is superb I really like the image rendering of this lens - at all focal lengths. I have found many uses for it, from wildlife photography to portraiture. I plan to also use it for astro-imaging. As many have already pointed out, it is heavy. But it is not so large as to be ungainly. Overall, I am delighted with this lens and highly recommend it. I did a photo shoot with the Tamron SP 70-200mm f/2.8 Di Vc USD G2 a couple years ago. From an imaging standpoint, it was good, but I've found the Sigma DG OS HSM Sport lens to be better.

Excellent in every way This lens takes some of the nicest pictures out of any lens that I have ever used. Overall color rendition is excellent, sharpness is superb, and the overall quality of the lens is top notch. Even with the weight of the lens, it is very well balanced so that it does not feel as heavy as it actually is. I would highly recommend Sigma's new art and sport series lenses. They are excellent build quality with top of the line image quality for an unbeatable price!