With all three lenses mounted and tested on a Nikon D3x DSLR the Overall DxOMark Scores demonstrate no significant difference between the Nikon AF-S 85mm f/1.4G, which scores 34, and the Nikon AF-S 85mm f/1.8G with 35. With a Lens Metric Score for Sharpness of 19P-Mpix, compared to 17P-Mpix and a Transmission Score of 1.7TStop compared to 1.9TStop the f/1.4 version of these two Nikon 85mm primes just edges out its f/1.8 rival. However, in terms of distortion and vignetting the cheaper f/1.8 version just has the edge, although the difference is so small it shouldn’t be noticeable. Of course if you’re working in very challenging low-light conditions or would like the stronger depth-of-field effects possible with the f/1.4 version then this is the better lens, but costing $1649 all that extra money only buys a minor improvement in overall sharpness.
The Sigma 85mm f/1.4 EX DG HSM also boasts some very good Lens Metric Scores but it doesn’t perform quite as well as the two Nikon lenses and finishes 3rd in this comparison with an Overall Score of 30. In terms of Transmission, Distortion, Vignetting and Chromatic Aberration the results are similar and although the Sigma only just loses out to the Nikon f/1.8 version for Sharpness, 16P-Mpix to 17-P-Mix, results are not as homogeneous across the frame at the wider aperture settings, which has cost the Sigma f/1.4 EX DG HSM in the Overall DxOMark Score.