The Sigma 70-200mm F2.8 EX DG OS HSM is a bold attempt to challenge the quality and functionality of some of the very best lenses on offer today - the fast image-stabilized telezooms from Nikon and Canon.
Very sharp across the frame when stopped down; Minimal color fringing/chromatic aberration of any description; Fast; silent; accurate autofocus with manual override; Very effective image stabilization; Decent build quality; Clever design tripod mount which is quick and easy to remove with the lens...
Somewhat soft and low in contrast at F2.8 towards the edges; especially on full frame cameras; Can give somewhat harsh rendition of out-of-focus backgrounds at longer focus distances; No focus limiter switch; No weathersealing; Susceptible to flare with direct light sources in or close to the frame,...