Sigma Corporation has announced the launch of the new 17-70mm F2.8-4.5 DC MACRO
lens, an ideal large aperture standard zoom lens for digital SLR cameras featuring
an APS-C size image sensor. The lens has a minimum focusing distance of 20cm
(7.9") throughout the entire zoom range. Maximum magnification of 1:2.3
enables close-up photography like a macro lens. The new lens design and multi
layer lens coating reduces flare and ghosting. A Special Low Dispersion (SLD)
lens and two aspherical lens elements provide excellent correction for all types
of aberrations and produce a high level of optical performance throughout the
entire zoom range.
This lens offers a large aperture of F2.8 at 17mm wide angle and yet it is
compact, with an overall length of 82.5mm (3.2") and diameter 79mm (3.1").
The lens design incorporates an inner focusing system, which ensures fast AF
speed as well as prevents the front of the lens rotating, making it particularly
suitable for use with circular polarizing filters and petal shaped lens hoods.
This lens is also equipped with Zoom Lock Switch that eliminates "Zoom
Creep" during transportation.