The Sigma 18-200 mm f/ 3.5-6.3 DC OS (HSM)
diagonal angle of view 69.3°- 7.1° (1.7х)
Equivalent focal length 28-320 mm (1.6х)
max. magnification 1:3.9
minimum aperture 22 - 40
Diameter 79 mm
max. focal length 160 mm
rotation angle of the focusing ring approx. 45°
weight 600 -610 g
LH780-04 hood included
The Sigma 18-200mm F3.5-6.3 DC OS HSM is a compact all-purpose zoom lens with 11x zoom ratio equipped with an optical image stabilizer and an HSM autofocus drive (ultra-sonic motor for the Nikon bayonet mount only, therefore it is not marked with HSM at an American website).
The Sigma18-200 mm f/ 3.5-6.3 DC OS HSMis dedicated for small-format DSRL cameras and cannot be used on full-format and film cameras. Its optical scheme includes three aspherical lenses and one SLD lens. Super multi-coating reduces flare and halation, and corrects color rendering.
While zooming in, the lens becomes 6 cm longer.. Internal focusing eliminates the front element rotation, which enables the use of a polarized filter and a petal hood. The lens is equipped with a zoom lock mechanism at 18 mm, which prevents barrel extension under its own weight when the lens is directed downwards.
The OS of the Sigma 18-200 mm f/ 3.5-6.3 DC OS HSMhas just an On/Off switch, but a single mode is able to detect panning. The distance scale is marked on the lens barrel. A small angle of focusing ring rotation hampers precise manual focusing. There is no f-stop at infinity. The direction of the focusing ring and zoom rotation is analogous to that of Canon.
The Sigma 18-200 mm f/ 3.5-6.3 DC OS HSM can really provide a 0.32х magnification at the distance of just 35.5 cm at the maximum focal length of 200 mm. As a result, the working distance is rather hard - 14.5 cm to the lens. It should be taken into account that at the closest focusing distance the focal length of 200 mm turns into approximately 135 mm.
The variant for the Nikon bayonet mount ( G type lens without aperture ring) is equipped with a built-in motor, and the autofocus functions on all cameras. Though 'HyperSonic Motor' has been announced for Nikon only, it is an ordinary micro-motor, but not a ring-type. Therefore there is no special difference discernible between a Nikon with HSM and a Canon without HSM. In both cases the focusing ring rotates during autofocus operations, and FTM mode is unavailable.
Links to online resources:
Posted by: dv Date of publication: 31.10.2010