Sigma 50-200mm f/4-5.6 DC OS HSM £299.99
19th Nov 2011 | 17:06
Small but feature-packed, this Sigma zoom lens aims to go large on value for money
Designed specifically for APS-C cameras with smaller than full-frame sensors, as denoted by its 'DC' suffix, the Sigma 50-200mm f/4-5.6 DC OS HSM zoom lens is available in Canon, Nikon, Pentax, Sigma and Sony mount options. Once you take the crop factor into account, the effective zoom range is 75-300mm in all versions apart from Canon-fit, where it's 80-320mm.
Apart from its extremely compact build, other headline attractions include Hypersonic Motor (HSM) autofocus and Sigma's optical stabiliser (OS) system. It's all good news, considering that this is one of the cheapest telephoto zoom lenses on the market.
Measuring just 74 x 99mm and weighing 420g, the Sigma 50-200mm OS takes up little room in your kit bag and, even at its maximum telephoto zoom setting, it only extends to 161mm with the lens hood fitted. The design is based on 14 elements in 10 groups, complete with one Special Low Dispersion (SLD) element and an eight-blade diaphragm.
The maximum aperture of f/4.5-5.6 through the zoom range can be reduced down to f/22-32.
Sigma claims a 4-stop advantage from the optical stabiliser in this DSLR zoom lens, and the HSM autofocus is fairly quick and quiet. However, it's not Sigma's more advanced ring-type HSM, so it's not massively rapid and lacks full-time manual override.
The closest focus distance is 110cm, which enables a maximum magnification factor of 0.22x at the 200mm zoom setting. Focusing is internal, so the front element neither extends nor rotates, making it ideal for use with a circular polariser or other rotation-sensitive filter. The lens has a relatively small 55mm filter thread and comes complete with lens hood.
Build quality, handling and performance
Build quality and handling
For such a small and lightweight lens, the build quality of the Sigma 50-200mm f/4-5.6 DC OS HSM feels quite robust and, unlike the Nikon Nikkor AF-S DX VR 55-200mm f/4-5.6G IF-ED, the mounting plate is metal rather than plastic. There's no hint of zoom creep, and the zoom ring has a smooth action throughout its entire range.
The focus ring is quite large, which is a bonus for manual focusing, but it rotates in autofocus mode. The upshot is that, when holding the camera and lens naturally, it's easy to foul the action of the focus ring with your fingers. At least there's a focus distance scale printed on the front edge of the focus ring, which is often lacking in budget lenses.
Optical quality in terms of sharpness is the opposite of Nikon's competing 55-200mm VR lens. The Sigma 50-200mm f/4-5.6 DC OS HSM is more typical of telephoto zooms, delivering sharper images at its shorter and mid-range focal lengths. At the maximum telephoto setting, sharpness drops off noticeably, especially at larger apertures of f/5.6 to f/8.
On the plus side, vignetting is kept well under control, and the lens produces plenty of contrast even in dull lighting conditions. Barrel distortion is a little noticeable at the 50mm end of the zoom range, as is pincushion distortion between 135-200mm.
The optical stabiliser is well worth having, although it only gave a 3-stop advantage in our tests, falling a little short of Sigma's 4-stop claim.
Taken at 200mm, f/5.6
The Sigma 50-200mm f/4-5.6 DC OS HSM is a very compact telephoto zoom lens with some nice features, including optical stabilisation, reasonably rapid and quiet HSM autofocus, and internal focusing. Even so, the stabiliser only consistently gave a 3-stop benefit in our tests, and handling can be a little awkward, since it's easy to foul the rotating focus ring during autofocus.
There's an impressive range of features packed into a very compact package.
The 50-200mm zoom range is relatively modest and sharpness isn't particularly good at the telephoto end.
Overall, the Sigma 50-200mm f/4-5.6 DC OS HSM is a decent buy at the price.