Looks like a good lens, very limited stock though (if any), definately none near me in central Scotland.
The Sigma 28-70mm f/2.8 EX DG is a small, lightweight and yet Robust, large aperture zoom lens.
* EX DG Lens Series; Designed to give an excellent performance with Digital SLR Cameras as well as 35mm Film Cameras.
* Super Multi Layer (SML) coating reduces ghost and flare.
* Two pieces of Special Low Dispersion (SLD) elements and four aspherical lenses provide high quality images throughout the entire zoom range.
* Minimum focusing distance of 33cm at all focal length
Large and constant aperture zoom lens ideal for digital SLR cameras. The power layout of the lens is specially optimized for digital SLR cameras, and Super Multi Coating gives superb colour performance whilst cutting down flare and ghost.
Two SLD elements and four aspherical lenses provide the ultimate correction against distortion as well as all types of aberration, especially spherical aberration. Its advanced optical design ensures high performance throughout the entire zoom range.
The use of aspherical lenses in the construction of this lens not only corrects aberrations but also produces a very small and lightweight lens design. Its compact, yet robust, construction has an overall length of 87.2mm, maximum diameter of 74mm, filter size of 67mm and weight of 510g.
It has a minimum focusing distance of 33cm at all focal lengths and a maximum magnification ratio of 1:4.4 which is very convenient for close-up photography. The inner focus system allows the lens to be focused without rotating the front element, therefore a Petal-type hood and circular polarizing filters can easily be used.
* Focal Length: 28-70mm
* Minimum Aperture: f/22
* Lens Construction: 14 Elements in 12 Groups
* Focusing System: Internal Focusing
* Angle of View: 75.4-34.3°
* Number of Diaphragm Blades: 9 pcs.
* Minimum Focusing Distance: 33cm
* Maximum Magnification: 1:4.4
* Filter Size (diameter): 67mm
* Lens Hood: Petal shape bayonet type hood
* Dimensions: Diameter 74mm x Length 87.2mm
* Weight: 510g