Sigma 17-70mm F2.8-4 Contemporary
Specifications
The Sigma 17-70mm "Contemporary" lens features Sigma's latest technologies, including full-time manual focus override, silent HSM autofocus, super multi-layer coatings, and a thermally-stable composite (plastic) barrel. Its front filter thread diameter of 72mm is not shared with any genuine Pentax lens.
Its optical formula of 16 elements in 14 groups has been redesigned compared to the previous version of this lens; it also employs a total of 5 SLD, FLD, and aspherical elements.
| Lens Name | Sigma 17-70mm f/2.8-4 DC Macro HSM |
| Optical Formula | 16 elements in 14 groups. Aspherical and super-low dispersion elements |
| Image Circle | APS-C Only |
| Image Stabilization | Yes, in-body (Pentax) in-lens (Canon, Nikon, Sigma) |
| Autofocus Type | Built-In HSM Motor |
| Field of View | 79.7° to 22.9° diagonal |
| Aperture Range | F2.8 - F22 at 17mm F4 - F22 at 70mm |
| Aperture Blades | 7 |
| Aperture Ring | N/A |
| Max. Magnification | 0.36x (1:2.8) |
| Minimum Focusing Distance | 22cm |
| Internal Focus | Yes |
| Internal Zooming | No |
| Quick Shift Manual Focus | Yes |
| Filter Diameter | 72mm |
| Cap | Plastic, pinch type |
| Hood | Included, petal-style |
| Case | None included |
| Diameter x Length | 79 x 82mm / 3.11 x 3.23 in |
| Weight | 465g / 16.4 oz |
| Mount Designation | KAF3 |
| Weather Sealing | N/A |
| Price (US MSRP) | |
| Other Available Mounts | Nikon F, Canon EF-S, Sony Alpha, Sigma |
As one of Sigma's latest lenses, this 17-70mm is compatible with the Sigma USB dock, a $59 PC accessory that allows you to calibrate the lens and upgrade its firmware at home. As of the writing of this review (June, 2013), the USB dock is available for Canon and Sigma mounts, coming soon for Nikon mounts, and not yet announced for Pentax and Sony mounts.
