LensTip.com

Lens review

Sigma A 35 mm f/1.4 DG HSM

12 December 2012
Szymon Starczewski

7. Coma, astigmatism and bokeh

The coma correction is a strong point of the tested Sigma. In the corners of the APS-C/DX sensor the influence of that aberration is really negligible. In the corners of full frame you can notice some distortions of the image of a diode but they are not so significant to provide a reason to complain. Once again the Sigma fares much better than the Canon, the Nikkor and the Sony, a bit better than the Zeiss and slightly better than the Samyang. Once again the best results in this class belong to the cheapest lenses…

Sigma A 35 mm f/1.4 DG HSM - Coma, astigmatism and bokeh

When it comes to the astigmatism you shouldn’t be bothered either. An average difference between horizontal and vertical MTF50 function values amounted to 4% which is a very good performance.

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You can’t have any serious reservations concerning the defocused light points. Perhaps the light spread is not perfectly even but the local extremes and rings are not very intensive. There is just one thing that makes us worried – even after a significant stopping down of the lens the circle is significantly distorted in the frame corner. If you want to know how the circles should look like in this type of equipment have a glance at this chapter of our Zeiss Distagon T* 35 mm f/1.4 ZF.2 test.

An additional effect which many people might not like is the splitting of straight lines behind the focus – some of our sample shots show it pretty well.

Sigma A 35 mm f/1.4 DG HSM - Coma, astigmatism and bokeh