I have written two reviews so far of this lens on my blog, and still cannot say enough good things about it. It has worked very well for me, enabling me to get some great moments with an elk in Rocky Mountain National Park as well as good shots of my daughter for her senior picture collection.

This is a very nice piece of glass especially for the price. Would definitely recommend it to anyone on a budget. Shoots clear and precise, the zoom does have a little drag but no worse than the two Zukios that I have. Will certainly be my every day all around lens.

I bought this lens for my Olympus e-510 three months ago and waited to see its performance before writing this review. I hope it would be helpful for the readers.

First I must tell that it is fully compatible with my Olympus e510 and it is perfoming very well. If you have any doubt about its compatibility with your camera, I strongly recommend you to visit Sigma official web site to read the "zoom products'" specification table. You can detailed information about the Sigma lenses and their compatibility issues.

This lens's 4/3 feature empowers the zoom to a great extend, the 35mm equilivance of that is 110mm to 400mm. That means you can do anything you want with such a powerful zoom.

The picture quality is excellent, the lens has both Manual and Auto focus feature so it lets you to become the part of the picture. I bought my Olympus Evolt E510 with 14-42mm f/3.5-5.6 Zuiko Lens from Amazon.com. Then I bought Sigma 55-200mm instead of 40-150mm f/4.0-5.6 Zuiko. I paid couple of dollars more but got 50mm more (100mm for 35mm equilivance or 4x optic) well and very happy with my decision.

It's a good product and Great value for the money paid!

Despite what some reviewers have stated, I found the IQ produced by this lens to be unacceptable. The lens is cheap compared to the Zuiko 50-200mm or even the Zuiko kit 40-150mm and it gives a nice focal range but that's about it. Images are soft (unless the lens is stepped down to f8.0, which becomes a problem in moderate to low light conditions) and it produces a yellow cast, visible in most shots. I should have listened to the many negative reviews I came across and avoid it. In the end, I sent it back to Amazon for a refund. I won't recommend it not even if you are on a budget. Save you money util you can afford something better. I bought the Zuiko 70-300mm instead and that's one great lens...worth every penny!!!

I couldn't afford the pricey lenses so I thought I'd give this one a try. While it is a good lens, it lacks the finesse that an Olympus lens has. Focus and telephoto movements of the lens aren't nearly as smooth as the Olympus. I guess I sacrificed some of the refinements of a high end lens when I went with Sigma. Don't get me wrong, it's a great lens and suits my needs well. I'm happy with the purchase.