Sigma 668-110 / 668110 17-70mm F2.8-4 DC MACRO OS HSM For Sigma Cameras. This large aperture standard zoom lens offers an aperture of F2.8 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 F2.8 makes this lens ideal for hand held photography as well as producing an attractive background blur and high speed auto focus. This lens has a minimum focusing distance of 22cm (8.7??) 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 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.
