AF Micro-Nikkor 60mm f/2.8D
D850 @ x 0.41
Excellent centre resolution but corners not so good on a FX sensor (see performance on D500 DX sensor)
Resolution: Centre resolution is excellent from fully open at f/3.3 and stays high until stopped down to f/16. Corner resolution is very weak in corners fully open but improves as the lens is stopped down to f/16. This lens performs best on a DX sensor for macro.
Chromatic aberration: Modest levels and much better than the more modern Nikon 60mm f/2.8 ED
Vignetting: High fully open and moderate from f/5.6 stopped down
Macro Sweet Spot: f/11-f/16