Sigma 18-200 mm f/3.5-6.3 II DC OS HSM
- compact dimensions for such a wide focal lengths’ range,
- very good image quality in the frame centre,
- good image quality on the edge of the frame at 18-50 mm focal lengths,
- chromatic aberration not higher than medium,
- distortion at the widest angle of view noticeably lower than that of competitors,
- low coma,
- well-corrected astigmatism,
- decent work of autofocus,
- image stabilization as efficient as 3 EV,
- versatile range of focal lengths.
- weak image quality on the edge of the frame at 100-200 mm focal lengths,
- huge vignetting throughout the whole focal range,
- weak performance against bright light,
- distortion for bigger focal lengths higher than that of the competitors.
Perhaps the most important question this review should answer is whether the new model of the tested lens is better than its predecessor. The answer seems to be positive. The resolution of the new lens is similar to that of the older model; the chromatic aberration, distortion on wide angle, coma and astigmatism decreased. The vignetting and work against bright light got worse but it was compensated by adding an HSM motor, more efficient stabilization and noticeable decrease of physical dimensions which made the Sigma 18-200 mm OS II the smallest lens of this class available on the market. Overall, there are definitely more steps forward than backward.
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Compared to its rivals, the Sigma shouldn’t be ashamed of anything. It is definitely better than the Canon 18-200 mm IS. The Nikkor 18-200 mm VR represents more or less the same quality of optics; it is faster but also more expensive. It should be emphasized that the suggested price of the Sigma is hardly low. 2000 PLN for a 18-200 mm megazoom lens is steep but its predecessor, when launched on the market, had a price tag even by 200 PLN higher. Here Sigma also took a step in the right direction.
The most serious competitor of the Sigma seems to be the Tamron 18-270 mm VC. It is a lens which fares decently well, being equipped with an image stabilization, having a wider range of focal lengths to boot; it is also by 100-200 PLN cheaper than the Sigma. Assuming that the current price of the Sigma is so high just because it is still a novelty on the market and after several months it might decrease, even if only slightly, it might become a very interesting option for amateurs of this kind of equipment. They might be tempted not only by good performance but perhaps mainly by small dimensions which are important to megazoom users as they often take their lenses with themselves on trips and journeys.