LensTip.com

Lens review

Sigma A 20 mm f/1.4 DG HSM

3 November 2015
Arkadiusz Olech

6. Distortion

At the beginning of this chapter you should remind yourself the results of the Nikkor AF-S 20 mm f/1.8G ED in this category which really rose the standard pretty high. On the small APS-C/DX sensor it showed a slight barrel distortion of a value of −0.89% which, on full frame, reached a level of −1.53%.

The Sigma A 1.4/20 cannot boast of such a good result. It is true that on the smaller sensor it reaches just −0.66%, a level lower than the Nikkor, but it might have been caused by the differences in the size of the Nikon’S D7000 detector used in the test of the Nikkor and the detector of the Canon 50D, used in the case of the Sigma. When you try to take objective measurement on full frame the result of the Sigma is actually worse, amounting to −2.15%. The difference is perhaps not big but still the fact that the rival managed to perform a bit better is worth your notice.

As a kind of consolation you might add that, compared to the Sigma 20 mm f/1.8 EX DG Aspherical RF, there is noticeable improvement. The older Sigma had distortion of −2.2% already on the small APS-C/DX sensor. When compared to the older 1.8/20 or 2.8/20 constructions the progress is evident.


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

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

Canon 50D, 20 mm
Sigma A 20 mm f/1.4 DG HSM - Distortion
Canon 5D MkIII, 20 mm
Sigma A 20 mm f/1.4 DG HSM - Distortion