(From Sigma lens literature) The Sigma Corporation is pleased to announce the new Sigma 17-70mm ƒ/2.8-4 DC MACRO OS HSM.
This large aperture standard zoom lens offers an aperture of ƒ/2.8 at the 17mm focal length and is ideal for many situations such as portraits, sports, macro and general photography. The OS (Optical Stabilizer) function offers the use of shutter speeds approximately 4 stops slower than would otherwise be possible. For Sony and Pentax mount, the built-in OS function of this lens can be used even if the camera body is equipped with an anti-shake function. As the compensation for camera shake is visible in the view finder, the photographer can easily check for accurate focus and ensure there is no subject movement. The maximum aperture of ƒ/2.8 produces an attractive background blur and improves autofocus speed.
This lens has a minimum focusing distance of 22cm (8.7in.) throughout the entire zoom range and maximum magnification ratio of 1:2.7, making it ideal for close-up photography. It is possible to focus as close as approximately 4.7cm (1.9in.) from the tip of the lens to the subject making this lens particularly useful for close-up photography.
Three aspherical lenses and one ELD (Extraordinary Low Dispersion) glass element provide excellent correction for all types of aberrations. High image quality is assured throughout the entire zoom range. The Super Multi-Layer Coating reduces flare and ghosting and provides high contrast images. The incorporation of HSM (Hyper Sonic Motor) ensures a quiet and high speed AF. This lens has a rounded 7 blade diaphragm which creates an attractive blur to the out of focus areas of the image. The inner focusing system eliminates front lens rotation, making the lens particularly suitable for using the supplied petal-type lens hood and circular polarizing filters.
Notes:
- Vignetting will occur if the lens is used with digital cameras with image sensors larger than APS-C size or 35mm SLR cameras.
- It is not possible to use the built-in OS function and AF of this lens, when using with Pentax ist* series and K100D DSLR cameras.
- Autofocus on Pentax version only available on K10D and newer bodies offering HSM/SDM support.
- For Pentax and Sony mount, when the OS function of lens body is used, please turn the stabilizer function of camera body off.
