Sigma 120-400mm f/4.5-5.6 DG APO OS HSM NikonBy Kevin Carter - Wednesday February 13 2013 Lens Review
The Sigma 120-400mm f/4.5-5.6 DG APO OS HSM is interesting for its longer focal lengths, equivalent to a 180-600mm on a Nikon DX body (and slightly more on a Canon APS-C). On a full-frame camera, it achieved a respectable DxOMark score of 15.8 though it dropped to just 11 on a Nikon D7000 (a slightly higher than on a D300s). Highpoints, apart from the extra reach, include consistent resolution across the image field (the Acutance map above shows the lens at 400mm), as well as good control of chromatic aberration, while the disadvantage of vignetting at maximum aperture is really only an issue for FF bodies. While not as pricey as some, $1,000 is still a sizeable figure given the performance at 400mm.