I uttilise The lens on this D800 since November 2013. With Aspherical Elements and nano treatment, I expect that this is a big performer The lens is quite appropriate. The objective solves the D800 sensor in the center of f / 2.2; a sacred performance. When we close the diaph there at the edges making progress; f / 2.8 it is perfectly stitched on 80% of the surface of the image and f / 4 it's perfect from one corner to the other. This is much better than zoom lenses pro f / 2.8. Vignetting is fairly well controlled, and not at all annoying after f / 2.8. The distortion is present, but automatically corrected by the box if you do jpeg (perhaps this is why other reviewers have not seen?). If you do the RAW camera raw possesses a profile for this goal very well that corrects distortion and vignetting. The goal presents a field curvature, ie the depth of field is not a plane parallel to the sensor. So if your subject is on the side, you can not make the point with center focus and crop. We must uttiliser collimators for optimal lateral result and generally way not to move part once the point is made. For af-s, auto-focus could be faster. My two optical autrees Af-S (50mm f / 1.8 and 17-35 f / 2.8) are both faster.
So Conclusion: a very high resolution lens that gives satisfaction on the image quality, but the speed of the af a little disappointing and field curvature can surprise.
For those who read English, I wrote a full review of this objective: [...] (and for others, it's still an opportunity to see images made with this 28)
