LensTip.com

Lens review

Canon EF 14 mm f/2.8L USM II

17 November 2011
Szymon Starczewski

7. Coma, astigmatism and bokeh

Coma is corrected very well if you work on the APS-C sensor. When moving to full frame, the troubles start. Perhaps its level is not huge there but it remains certainly significant and it contributes greatly to the resolution decrease on the edge of the frame.

Canon EF 14 mm f/2.8L USM II - Coma, astigmatism and bokeh

As we already mentioned the astigmatism is also a problem. In that case it is difficult to divide off its influence from the lateral chromatic aberration unambiguously but it is certainly significant. The average difference between horizontal and vertical MTF50 values is 17% here which is a high result. It’s a pity that such an expensive lens must have such problems.

- - - - - - - - - - - - - - - - - advertisement - - - - - - - - - - - - - - - - -

- - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - -

Photos posted below show off-focus images of a diode positioned in different frame areas; they were taken for different aperture values.

Canon EF 14 mm f/2.8L USM II - Coma, astigmatism and bokeh