The Sigma 17-50mm f/2.8 EX DC HSM (Sigma part #583109) is a fast aperture standard zoom lens for Pentax DSLRs with APS-C format sensors. It's an ultra versatile all-purpose lens well suited for photography of almost any sort; it zooms from well inside wide-angle territory (perfect for landscapes, groups, documentary) all the way to the start of the telephoto range (where more flattering portraits are possible). In challenging available light situations the bright f/2.8 maximum aperture makes it easier use fast shutter speeds, and improves viewing ease, and aids all types of focusing.
Auto Focusing performance is fast and responsive thanks to the lens' HSM (HyperSonic Motor) system with full time manual focus override. The lens focuses down to a distance of just 11 inches throughout the entire zoom range and has a maximum magnification ratio is 1:5 (unaugmented).
Sigma DC lenses have optics designed exclusively for the unique challenges and performance characteristics of APS-C and DX imaging sensors. The 17-50mm F/2.8 EX DC HSM design incorporates three Aspherical elements and two FLD ("F" Low Dispersion fluorite equivalent) glass elements to minimize optical aberrations and deliver superb color, contrast, and clarity.
The Sigma 17-50mm f/2.8 EX DC HSM is a great option for Pentax APS-C DSLR shooters looking for a bright high performing general purpose lens.
- Multipurpose standard zoom for Pentax DSLRs*
- Sigma DC Series: optimized exclusively for 24x16mm size sensors
- For Pentax K-Mount (KAF3)*
- Wide to short tele zoom range
- Equivalent to a 27.2-80mm in 35mm format
- Bright constant f/2.8 maximum aperture
- 7 blade rounded diaphragm
- Excellent image quality: sharp contrasty images with great color
- 17 elements in 13 groups
- 3 Aspherical elements (2 glass molded, 1 hybrid aspheric)
- 2 FLD ("F" Low Dispersion) glass elements
- Super Multi Coated optics
- Fast HSM (HyperSonic Motor) is responsive and quiet
- Efficient IF (Internal Focus) design, non-rotating filter ring
- Close focus to 0.28m (11in)
- Compact form factor, weighs 565g (19.9oz)
- Zoom lock switch prevents barrel extension while carrying
- Uses 77mm filters
Available accessories include: reversible bayonet lens hood and 77mm filters.
*Compatibility note: electronic incompatibilities can exist with newer cameras and earlier versions of some Sigma lenses. Please contact us for help checking compatibility.