This lens is an update to the AF Micro-Nikkor 60mm f/2.8D released in 1993. It is a new lens design but in some ways loses some of the best characteristics of the older design, particularly the low level of chromatic aberration. This chromatic aberation can be removed in imaging software. The newer design does however not exhibit such a big reduction in maximum aperture at maximum magnification ( f/4.8 compared with f/5.6) 

Distortion: This lens exhibits moderate barrel distortion of -0.2%  at x0.27 and x0.5 but 0.96% pin cushion distortion at x1 on a D500. On a D800 distortion is -0.2% barrel at x0.41 and 0.67% pin cushion at x1

At f/8 corners are almost as sharp as the centre