Features:
- Dedicated to Pentax AF SLR cameras
- Silent hyper-sonic motor (HSM) focusing system
- Full-time manual focus can be used at any time
- Nonrotating front barrel
- Zoom lock mechanism helps reduce "zoom creep" distortion
Description:
Encompassing all popular focal lengths from the 50mm "normal" to 500mm ultratelephoto, the Sigma 50-500mm f4-f6.3 EX RF HSM hyperzoom lens gives you amazing versatility, plus a 10:1 zoom ratio, and its rear focus system ensures fast, convenient manual focus. The use of an apochromatic design plus four optical elements composed of special low dispersion (SLD) glass, a seven-group zoom system, and multicoated optics combine to give you high-quality images. In addition to its fast, responsive AF function, you can also use the full-time manual focus at any time. The zoom lock mechanism helps reduce the "zoom creep" distortion that can occur when your lens is tilted up or down. Sigma used magnesium in the tripod mount to help reduce the weight of the lens, just over 65 ounces, yet still maintain the strength and rigidity necessary to support its weight. This model is dedicated to Pentax AF SLR cameras.
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