Nice lens. My copy has cleaning marks on the front element. Thankfully the coating is intact. I've begun testing this lens on my Eos-T2i. It is reasonably easy to focus up to 15 feet, but after that it jumps straight to infinity. Focus dampening is very light, just like most Nikkors. Aperture clicks nicely, but only in one stop increments. It's sharp wide open thru f11. Contrast is excellent at all apertures. Distortion is not noticeable on the Eos M3 and neither is vignetting. Bokeh fringing is very well controlled. Only a loss of contrast is noticeable with no actual color shifting. I expected great black and white from this lens and it delivers.

So what's not good about it? The usual things; flare and fringing in high contrast scenes. Flare causes a significant loss of contrast and fogging. Use a lens hood at all times and avoid shooting backlit scenes.