After the Tamron 18-270mm and Sigma 18-250mm reviews, the DxOmark team offers you a series of short reviews for the 18-200mm lenses tested on our website:
For summer 2011, DxOMark delivers its super-zoom, all-in-one selection for Canon and Nikon.
What are the interesting features of these lenses?
What are their limitations?
Once you are aware of these limitations, you’ll be able to find a good compromise and maybe you will agree with us that "you get you pay for."
As explained before, these lenses are not designed to provide the best results in low lighting conditions, so do not be surprised if you find their scores to be low.
The DxOMark scores for these seven lenses are very close and range from 5 (Sony DT 18-200mm mounted on the Sony A350 to 13 for the Sigma 18-200mm F3.5-6.3 DC OS Canon mounted on the Canon EOS 7D.
We want to point out that the Sigma 18-200mm OS score is a pretty good one for this kind of lens.
On resolution metrics, their results are very close as well. The Sony DT 18-200mm is the least sharp (37 lp.mm) of all. The others, such as the Nikon AF-S DX VR Zoom-Nikkor 18-200mm f/3.5-5.6G IF-ED achieve results close to 41 lp/mm.
All the results correspond to the lenses being mounted on the cameras with the best resolution available at this time on the DxOMark database:
Vignetting remains very well controlled on every lens, which is no great feat, as all the available apertures are small.
All Chromatic Aberration measurements show similar results except for the Sony 18-200mm at 200mm and the Sigma 18-200mm OS Nikon mount.
All lenses in this review present very close results on distortion: strong distortion at 18 mm and pretty well controlled for the focal superior to 50mm.
If you would like more choices, here are some interesting comparisons for super-zoom lenses on Canon APS-C cameras:
Surprisingly, we have a tie here: the DxOMark score ranges only from 8 to 9 for all 5 lenses, so they all should provide satisfactory images. Their features are also pretty similar (same aperture and stabilization for every model).
Note that the previous version of the Tamron 18 -270 achieves a better resolution metric: 44 lp.mm.
The best choice might be either the inexpensive Sigma 18-250mm F3.5-6.3 DC OS HSM Nikon or the light Tamron 18-270mm F/3.5-6.3 Di II VC PZD Nikon.
For further information, here are some interesting comparisons for super-zoom lenses on Nikon APS-C cameras: