DxOMark published their Sigma 20mm f/1.4 DG HSM Art Lens (Canon) review and test results. Tested on Canon EOS 5DS R, the Sigma 20mm f/1.4 DG HSM Art (Canon) Lens (Amazon, B&H, Adorama) achieved an outstanding DxOMark score of 40 points, making it the top-ranked Canon EF mount wide-angle lens in DxOMark database. Considering all EF options with a focal length of 24mm or wider, the Sigma 20mm Art prime offers the best scores for sharpness, vignetting, and chromatic aberration in this group.
Sigma 20mm f/1.4 A comparisons: The best bet
Conclusion from DxOMark:
The Sigma 20mm f/1.4 A is one of the sharpest lenses we’ve tested, ranking in 21st place for sharpness out of all the lenses in our database, with a score of 33 P-Mpix tested on the EOS 5DS R. Sigma’s flagship 20mm prime actually realizes more of the resolution potential of the lower-resolution 22.3Mp EOS 5D Mark III, however, with a score of 18 P-Mpix (equating to 80% of the 5D Mark III’s resolution compared to 66% for the 5DS R). To summarize, this lens is very sharp, offering edge-to-edge resolution between f/4 and f/16, and very good results at the wider aperture settings, too. If your photography demands great image quality results at 20mm, and you can live without a f/22 minimum aperture, you won’t go wrong with the Sigma 20mm f/1.4 A.
This revolutionary prime lens is designed to bring out the full potential of ultra-high-megapixel DSLR cameras. With a focal length of 20mm and F1.4 aperture, this lens delivers outstanding large-aperture brightness and bokeh.