Some people don’t realize this is a completely different lens than the older Sigma 70-200, not just the old lens with an Optical Stabilizer added. The OS version is clearly sharper at 200mm than the old one was, but maybe not quite as sharp at 70mm. Overall, though it is clearly an improvement.

If you’re expecting it to be indistinguishable from a Canon 70-200 f/2.8 IS II, then you aren’t going to be pleased — it can come close to matching it in the center, but not in the edges and corners, at least not at f/2.8. But it’s an excellent lens at a reasonable price. It also autofocuses quickly and accurately enough to be used for sports photography. It’s sharp in the center even wide open all the way to 200mm, although the edges won’t sharpen until f4 and improve further at f5.6. And the image stabilization is very good. I’d call it 3 stops which is not quite up to the Canon 70-200 f2.8 IS II, but better than the original Canon 70-200 IS.

For most people who will use this lens for sportshooting the corner and edge softness won’t be an issue. I recommend looking at the LensTips review below before making up your mind. Depending on how you shoot, it may be a great way to save some money compared to the Canon version, but for others it’s weaknesses may be an issue. One thing I will add, though: this lens is NOT 200mm focal length. It’s 180mm or so at the long end, noticeably shorter than the previous Sigma 70-200 or any of the Canon 70-200 lenses. If that’s important to you and you really need every bit of 200mm, this may not be the lens for you.

From long experience I’m only going to recommend this lens if your camera has autofocus microadjustment. We will, of course, test the lens before every rental, but one thing we know, like we know the sun is going to rise in the East, is that there is more camera-to-camera autofocus variation with third-party lenses. A given copy of this lens may be very accurate on one camera, backfocus on another, and frontfocus on a third.