Sigma 17-70mm f/2.8-4 DC Macro OS HSM Lens for Canon Digital SLR CA17-70OS

Sigma's 17-70mm F2.8-4 DC Macro OS HSM is the practical zoom! A large-aperture, standard zoom Lens for Digital cameras with an open-aperture value of F2.8 (at 17mm) and covers the most frequently used focal lengths. With an aperture fast enough to be used in many light situations, it's close focusing for use with very small object and its outstanding Optical performance make this is an ideal all-around lens for landscapes, portraits, still life studies, group shots and just about any everyday photo situation. The OS, Sigma's anti shake feature, offers the use of shutter speeds approximately 4 stops slower than would otherwise be possible. HSM ensures quiet and high speed AF capability. With a faster aperture than the typical camera "kit lens" it is an excellent choice for the photographer who has higher expectations for their photo equipment.
Features

Designed exclusively for use with smaller chip APS-c or 4/3 cameras

Offers Sigma's OS System (Optical Stabilization) allowing handheld photography even in low-light situation

Close focusing down to only 8.7" away for a 1:2.7 magnification which is approximately 1/2 life size

Three aspherical & ELD glass elements provide critical sharpness & low distortion

A Super Multi-Coating is used to reduce the occurrence of flare & ghosting and delivers high performance across the entire focusing range
Specifications

Lens Construction: 17 Elements in 13 Groups

Angle of View: 72.4-20.2

Number of Diaphragm Blades: 7

Miminum Aperture: f22

Minimum Focusing Distance: 22 cm / 8.7 in

Filter Size (mm): 72

Maximum Magnifications: 1:2.7

Dimensions (Diameter x Length): 79-88.9 mm / 3.1x3.5 in.

Weight: 535g / 18.9oz.