This great lens combines a 5 lens group zoom system with an aspherical lens element to deliver sharp high contrast images throughout the entire zoom range. Using Sigma's unique apochromatic lens design and three SLD glass elements, the aberrations usually found in ultra-telephoto lenses have been eliminated. And with Sigma's focusing system, the front lens group doesn't rotate, which makes using polarized filters a snap. A convenient built-in rotary tripod mount eliminates vibration during shutter release.
Sigma combined a five-lens group zoom system with an aspherical lens element when they designed the 170-500mm f5-6.3 APO aspherical lens. This combination gives your images sharp high-contrast images throughout the entire zoom range. Its unique apochromatic lens design and three SLD glass elements help eliminate the vibrations usually found in ultratelephoto lenses. Since the front lens group doesn't rotate, polarized filters are extremely easy to use. This lens also has a built-in rotary tripod mount to help keep the lens steady, reducing vibration during shutter release and keeping your images sharp and clear. This model is dedicated to Nikon AF SLR cameras.
1 THE BEST IN THE PRICE RANGE
I'm photographing wildlife as a hobby for about 6 years now and before this lens I used the regular 70-300 zoom lens and due to budget I could'nt buy any of the brand's telephotos until I found this lens ,at first I was suspicious because it seems too cheap for a 500mm lens but this was before I received my first photos and transparencies from the lab because it turned out to be way better than I could ever imagine, the photos were great, very nice color and contrast, not to mention the depth of field of a telephoto which is very shallow and makes the main object very strong ,the image comes with a very nice blurred background and a very shrp main objects ,image wise this lens is very good (not only for the price range )and the only drawback is the slow auto focus . Anyway, this lens forces the use of a sturdy tripod so you should take it in account. after about a year with this lens I can say that I'm more than satisfied ,there is no match for it in the price range
