Sigma 24-70mm f/3.5-5.6 Aspherical HF
(From Sigma lens literature) This compact and wide-angle lens covers a wide range of focal lengths from 24mm to 70mm in the medium telephoto range. It has an excellent imaging capability and very effective for general photography.
From 24mm wide angle to 70mm telephoto range, it has a minimum focusing distance of 40cm (15.7 inches) throughout the entire zoom range and enables macro photography with a maximum magnification of 1:3.8.
It makes use of aspherical lens elements to correct distortion and all types of aberration.
An HF (Helical Focusing) system is used to allow the front lens group to move linearly when focusing without the front of the lens revolving, making it suitable for the use a Petal-type hood and circular polarizing filters.
Sigma 24-70mm f/3.5-5.6 Aspherical HF User Reviews
1 out of 10 points and not recommended by Niel (7 reviews)NonePoor QC
Bought secondhand like most of my lenses this one had several issues.reviewed February 20th, 2007 (purchased for $60)
1. An extra screw, probably flex-circuit anchor, was found in the main zoom helix's lube.
2. Front elements cement starting to fail leading to image softening along with other internal contamination/growth.
Not a lens I'd buy again.