Sigma 17-70mm f/2.8-4 DC OS HSM Macro
This is a so-called “normal” zoom, which means that it covers the zoom range you are most likely to use. If you are like most photographers, a “normal” zoom is the lens you will be using most of time, so you need to weight your options carefully.
The big selling point of this lens us the f/2.8 aperture available at 17 mm, in combination with a 4.1x zoom range and the optical stabilzation (OS).
This is a consumer grade lens, and the build quality does not inspire confidence. The zoom sometimes creep. While carrying a “HSM”-label, I do not think the lens has a ring-type motor. The is no manual focus over-ride setting.
Comes with a petal shaped bayonet lens-hood.
Rating: Ed: -, User: - (normalized, 0=useless, 50=average, 100=excellent).
Mounts: Canon EF, Nikon F, Pentax K, Sigma SD, Sony A.
Aperture range: f/2.8-4 to f/22.
Optical zoom: 4.1x.
Close focus distance (CFD): 22 cm / 0.72 ft (from sensor plane).
CFD magnification: 1:2.7 / 0.37X.
Focus: AF (built-in, gear-type).
Filter diameter: 72 mm.
L x D, W: 83 x 79 mm, 535 g.
Approximate street price: USD 469 (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.