Sigma 17-50mm F2.8 EX DC OS HSM is an Auto Focus (AF)
Standard Zoom lens with APS-C / DX max sensor coverage and it is designed to be used with Pentax KAF3 mount cameras.
Lens Mount
Sigma 17-50mm F2.8 EX DC OS HSM is compatible with cameras that have Pentax KAF3 lens mount. Some of the latest released cameras that are compatible with the Pentax KAF3 lenses are , and .
Sigma 17-50mm F2.8 EX DC OS HSM is also available in Canon EF , Sony Alpha, Sigma SA and Nikon F (DX) mounts.
Focal Range
Sigma 17-50mm F2.8 EX DC OS HSM has a focal range of 17-50mm and 2.9X zoom ratio which has a 35mm equivalent focal range of 25.5-75mm when used on a APS-C / DX format camera.
Optical Image Stabilization
Sigma 17-50mm F2.8 EX DC OS HSM features an optical image stabilization system which helps to reduce the blur that occurs due to shaking during hand-held shooting.
Zoom Method
Sigma 17-50mm F2.8 EX DC OS HSM features Rotary (extending) zoom method where the length of the lens changes as you zoom in or out. This makes it possible to design the lens with a smaller minimum length ( generally when it is zoomed out) compared to internal zoom lenses. The disadvantages of this design are being harder to seal against dust and moisture, weight balance shifting while zooming and zoom creep in certain lenses.
Maximum Magnification Ratio
Sigma 17-50mm F2.8 EX DC OS HSM has a Max Magnification Ratio of 0.2x and has a minimum focusing distance of 0.28m.
Aperture
Sigma 17-50mm F2.8 EX DC OS HSM is a fixed aperture lens with a constant max aperture of f2.8 from 17mm all the way to the 50mm .
Optical Formula
Sigma 17-50mm F2.8 EX DC OS HSM's optical formula consists of 17 elements in 13 groups . Following special elements are used in this design:
- 2 FLD glass elements
- 2 glass mold elements
- 1 hybrid aspherical lens
Lens Hood
Sigma 17-50mm F2.8 EX DC OS HSM comes with a removable lens hood which is handy to reduce lens flare and glare in your photos.
Popular Comparisons of Sigma 17-50mm F2.8 EX DC OS HSM
Here is the eight most popular comparisons of Sigma 17-50mm F2.8 EX DC OS HSM amongst Camera Decision readers.