10 out of 10 points and recommendedHigh overall IQ, great AF focus accuracy, very high build quality for a non-OEM lens.Corner falloff wide open, focuses in the opposite direction of Nikkor lenses and lack of weather sealing gasket on lens mount.
This is the first f/1.4 lens for Nikon that I wouldn't hesitate using wide open, leaving little to be desired. With the possible exception of the 35/1.4 AFS G Nikkor, compared to other f/1.4 Nikkors optics in the 35/50 class, it is relatively free of coma and spherical aberration that hindered wide open performance of earlier lenses. Understandably, center sharpness is much better than corner sharpness but it's corners were much improved compared to earlier optics like the 35/1.4 AiS Nikkor. Stopping down to f/2, corner much improves falloff and by f/2.8 image sharpness is quite high over most of the frame. Unlike others who has AF issues with their samples, mine was fairly sharp right out of the box. Use of the Sigma USB Dock with a slight +5 compensation gave maximal sharpness at all distance settings. Since I use several AFS Nikkors and tele-extenders, the USB Dock eliminated the need of using one of the 12 memory settings on the camera's AF fine tuning.reviewed February 15th, 2016 (purchased for $899)