No doubt one of the sharpest lenses I ever owned. Period.
Just a trace of softness / veiling haze at full aperture, than from f/2 to f/11 it really shines. From f/11 the diffraction start to wreck his performance.
On infrared the only problem is to achieve correct focus at wide apertures, but if you use Live View or guess or stop down a bit you will regarded with a perfect rendition.
Full image:
100% crops:
In short a real Nikon legend. And did I mention that is 5 times cheaper than the Canon equivalent? (but keep in mind: the Canon is AF, and sharper at full aperture)
Rating: 
visible light & infrared
