Sigma 28-300mm f3.5/6.3 DG Macro Auto Focus Wide Angle Telephoto Macro Zoom Lens                 

This digitally optimized zoom lens provides a high zoom magnification of 10.7x. The new lens coating reduces flare and ghosting, a common problem with digital cameras and also creates an optimum color balance. The 10.7x zoom ratio covers a wide range of focal length from wide angle to tele-photo making this a highly versatile lens ideally suited for many types of photography. This lens features two Special Low Dispersion (SLD) glass elements and four Aspherical Lenses, to produce a high level of optical performance. Aspherical lenses provide excellent correction for all types of aberration while making a very compact construction possible.

The 28-300mm F3.5-6.3 DG MACRO lens has a minimum focusing distance of 50cm at all focal lengths and is equipped with a macro mechanism for close-up photography at 300mm telephoto, allowing a reproduction ratio of 1:3.

The zoom lock switch eliminates "zoom creep" during transportation, a convenient addition when traveling. The inner focusing system gives the advantage of a non-rotating front lens assembly, which is of great benefit when using polarizing filter and the matched Petal-shaped lens hood supplied.

Features
Digitally optimized super zoom lens with a 10.7x zoom magnification.
New multi layer lens coating minimizes flare and ghosting, a common problem with Digital SLR cameras.
Wide angle, Standard, Telephoto and Close up, the all-purpose zoom lens.
Two SLD (Special Low Dispersion) glass elements and four Aspherical Lenses produce superior optical performance.

Specifications
Construction 15 elements in 13 groups
Angle of view 75.4 to 8.2 degrees
F stop range 3.5-22
Closest Focusing Distance 19.7 in. (50cm)
Maximum Magnification 1:3
Filter Size 62mm
Dimensions (Length x Diameter) 3.4 x 2.9 in. / 86 x 74mm
Weight 17.3 oz. (490g)
For Canon
 For Nikon
 For Pentax