Surprisingly quality product for a price "almost" ridiculous

The price / quality of this lens is simply excellent. Having the chance to ride on the D800, I confirm that the score of 36 for this case DXO labs lens couple is found both in the quality of images produced. The Nikon equivalent cost 6-7 times more for certainly comparable results.
Remains the manual focus that makes it of little use when there is no time to make the correct setting. In the case of D800 and lens sighting of clarity, the focus is very easy, even if it has nothing to do with the Nikkor AF. In "quiet" portrait or reportage, it is perfect.