LensTip.com

Lens review

Sigma A 28 mm f/1.4 DG HSM

21 January 2019
Arkadiusz Olech

7. Coma, astigmatism and bokeh

Full frame 1.4/28 lenses, tested by us so far, have never managed to correct coma in a perfect way - it was quite visible even in the case of the expensive Otus. The Sigma A 1.4/28 in the corners of full frame is not free of that aberration either but the images of point-like source of light seem to be slightly better than the respective images produced by the Otus and the Nikkor AF-S 1.4/28. In this category, despite the lack of ideal performance, the Sigma should be praised anyway.

Center, f/1.4 Corner APS-C, f/1.4 Corner FF, f/1.4
Sigma A 28 mm f/1.4 DG HSM - Coma, astigmatism and bokeh Sigma A 28 mm f/1.4 DG HSM - Coma, astigmatism and bokeh Sigma A 28 mm f/1.4 DG HSM - Coma, astigmatism and bokeh
Center, f/2.0 Corner APS-C, f/2.0 Corner FF, f/2.0
Sigma A 28 mm f/1.4 DG HSM - Coma, astigmatism and bokeh Sigma A 28 mm f/1.4 DG HSM - Coma, astigmatism and bokeh Sigma A 28 mm f/1.4 DG HSM - Coma, astigmatism and bokeh


When it comes to astigmatism, understood as an average difference between horizontal and vertical MTF50 function values, we don’t have the slightest reservations. The value, measured by us, amounted to 2.7% which means you don’t have to worry about this aberration at all. In this category the Sigma once again prevails over its rivals in a decisive manner – a round of applause!


Please Support Us

The coronavirus crisis has been adversely affecting many businesses and, sad but true, ours is not an exception. Despite that difficult situation we would like to preserve continuity and high quality of publications available on all our websites. Still, we are now aware it might be impossible without additional financial help. That's why we would like to ask all those who visit, read, and care about Optyczne.pl, LensTip.com i Allbinos.com for support - it's enough you send us a small sum of money via PayPal. If a lot people decide to support our websites we think we'll stand a chance and survive next months without any lasting harm. We count on your support and understanding, stay safe and be healthy.

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

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

For a wide angle lens the appearance of out-of-focus areas is very nice indeed, with even light spread in the circles, without any local extreme points. If you examine these circles in the 1:1 scale you can notice a very delicately accented onion rings bokeh, most likely linked to aspherical elements of the lens. Still that effect is not distinct and you really have to look carefully in order to notice it. It’s also worth adding that mechanical vignetting makes itself felt rather strongly at the maximum relative aperture.

Center, f/1.4 Corner APS-C, f/1.4 Corner FF, f/1.4
Sigma A 28 mm f/1.4 DG HSM - Coma, astigmatism and bokeh Sigma A 28 mm f/1.4 DG HSM - Coma, astigmatism and bokeh Sigma A 28 mm f/1.4 DG HSM - Coma, astigmatism and bokeh
Center, f/2.0 Corner APS-C, f/2.0 Corner FF, f/2.0
Sigma A 28 mm f/1.4 DG HSM - Coma, astigmatism and bokeh Sigma A 28 mm f/1.4 DG HSM - Coma, astigmatism and bokeh Sigma A 28 mm f/1.4 DG HSM - Coma, astigmatism and bokeh
Center, f/2.8 Corner APS-C, f/2.8 Corner FF, f/2.8
Sigma A 28 mm f/1.4 DG HSM - Coma, astigmatism and bokeh Sigma A 28 mm f/1.4 DG HSM - Coma, astigmatism and bokeh Sigma A 28 mm f/1.4 DG HSM - Coma, astigmatism and bokeh