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Lens review

Tokina AT-X 116 PRO DX II AF 11-16 mm f/2.8

17 August 2013
Szymon Starczewski

7. Coma, astigmatism and bokeh

The coma is not corrected in a perfect way because at every focal length the image of a diode is slightly disfigured. Those distortions seem to be the most pronounced in the middle of the focal range. Still it is not a problem which should be considered serious.

To tell you the truth that result is actually a nice surprise – the first version of this lens fared much worse in this category.

Tokina AT-X 116 PRO DX II AF 11-16 mm f/2.8 - Coma, astigmatism and bokeh


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As we already mentioned in the chapter concerning the chromatic aberration, the astigmatism assessment is not easy. Officially the average difference between horizontal and vertical MTF50 function values amounts to 6.5%. As the lateral chromatic aberration contributes to that result you should treat it as just the upper astigmatism limit. The values up to 5% we consider to be low so you can say the tested lens corrects the astigmatism in a proper way.

When it comes to the appearance of defocused images it would be difficult to find anything admirable here. The rings of light in their centre are noticeably darker (which is connected to the already mentioned spherical aberration) and they are distorted in the frame corners, with visibly lighter rims. It is worth mentioning, though, that their shape is oval, not truncated – it means the vignetting mainly stems from optics, not mechanical obstacles.

Overall there are no reasons to complain here, especially that in these types of instruments it is difficult to obtain properly emphasized and significantly big defocused areas.

Tokina AT-X 116 PRO DX II AF 11-16 mm f/2.8 - Coma, astigmatism and bokeh