Sigma 120-400mm f/4.5-5.6 DG APO OS HSM
Overall optical performance is very good for most of the zoom range. Sharpness and contrast is slightly lower at tele end, and as usual with Sigma, edges are slightly softer than the centre. Sweet spot is between f/5.6 and f/13 on FX. There is virtually no distortions. Chromatic aberration flare and ghosting are well controlled. There is some vignetting between 200mm and 400mm. Stopping down to f/10 makes it go away. Bokeh is rough, but acceptable.
As usual with Sigma EX-lenses, it has a solid feel. Auto-focus is fast and quiet. The OS provides about two stops worth of stabilisation. Comes with tripod-collar.
No OS or HSM in Sony and Pentax versions.
Rating: Ed: -, User: - (normalized, 0=useless, 50=average, 100=excellent).
Mounts: Canon EF, Nikon F, Pentax K, Sigma SD, Sony A.
Aperture range: f/4.5-5.6 to f/22.
Optical zoom: 3.3x.
Close focus distance (CFD): 150 cm / 4.92 ft (from sensor plane).
CFD magnification: 1:4.2 / 0.24X.
Focus: AF (built-in, ring-type).
Filter diameter: 77 mm.
L x D, W: 204 x 93 mm, 1750 g.
Approximate street price: USD 899 (new, w/o tax).
Introduced: no data.
Sigma is a family owned manufacturer of photographic equipment founded in 1961 in Japan. The company's main business is to manufacture third party lenses. However they also produce third party flash units and, since 2002, their own line of DSLR and compact cameras. Sigma's digital cameras use a special sensor, developed by Foveon, that records full color information for every pixel. In late 2008 Sigma acquired Foveon.