Sigma 10-20mm f/4-5.6 EX HSM DC
Solid build. Good overall sharpness and well-controlled aberrations and flare. Some vignetting at all focal lengths. Distortions are generally well controlled, but a tiny amount of mustache distortion at the wide end. Some sample variation – most bad samples are uncentered, making one corner visibly less sharp than the others.
The Canon, Nikon and Sigma version feature a ring-type focus motor. There is no motor in the Pentax and Sony version.
This is my choice for ultrawide zoom. Since I bought it in March 2006, it has been stuck on the camera. It has become my favourite lens. For examples of images I've taken with this lens, please take look at my Flickr page.
Rating: Ed: 85, User: - (normalized, 0=useless, 50=average, 100=excellent).
Mounts: Canon EF, Nikon F, Pentax K, Sigma SD, Sony A.
Aperture range: f/4-5.6 to f/22.
Optical zoom: 2x.
Close focus distance (CFD): 24 cm / 0.79 ft (from sensor plane).
CFD magnification: 1:6.7 / 0.15X.
Focus: AF (built-in, ring-type).
Filter diameter: 77 mm.
L x D, W: 81 x 84 mm, 470 g.
IR: May produce a hotspot.
Approximate street price: USD 480 (new, w/o tax).
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.