"Left focus" repair attempt in Melville
My D800 needed different AF Fine Tune depending upon the AF sensor used. For instance, with my AFS 85mm 1.8, it needed -5 for the middle and the right AF sensors and -15 for the left sensor. With my AFS 35mm f1.4, it needed -7 in the middle, 0 on the right and -15 on the left.
It was difficult to know if it was within the specification. Therfore, while I was in Paris, I went to a Nikon Repair Center where you can tall to people. I gave them my D800 with the 85mm f1.8 and the AF Fine Tune turned off. They came back to me and confirmed that the left sensor was a little bit off.
Therefore, when I came back home, I've sent my D800 to Melville to get it repaired. I've recieved it yesterday. It is obvious that they have worked on it as now the center sensors of my new lenses need about +7 AF Fine Tune (they used to need -5). The left and the right sensor both backfocus. They both might need 0 AF Fine Tune on the 85mm f1.8. It is not so much, so it might be considered OK.
But, the worse is that now the focus depends on the light source. Outdoors the central sensor of the needs +5. It needs at least +15 (maybe +20) in my house with the light given by my bulbs. I did not have this problem before.
In the end, the discrepency in between the AF sensors is different but in the same order of magnitude. But now, it becomes completly light-dependent.
I still need to work a little bit on it, but it's very difficult to understand what's going on as the focusing system seems to be even less consistant from shot to shot as it was before...