I have a D5100 which has always been erratic with its focussing in auto area and I wasn't sure why in the beginning. I narrowed it down to the top focus point, which rarely achieved focus in single point mode. The rest of the focus points would focus perfectly in the same conditions with the same settings and pointing at the same point on the same subject. Typical settings of the camera would be 1/160 s, f1.8, iso 400 (in auto mode). The top focus point can only achieve focus if there was something of very strong contrast, the rest don't need that. This focussing issue makes the camera pretty unuseable for me.
This camera has been back at Nikon twice and has been returned with the same problem. The last time I asked them to list what work they'd done on the camera and the only part mentioning focus was this:-
"Body depth, body focus, AF accuracy checked and recalibrated if necessary."
As the camera hsa been to Nikon (UK) twice and come back in the same state, I am at my wits end with them. I am extremely disappointed. I always had a high regard for Nikon. I am not sure what I can do. I don't see a point in sending it back to Nikon (UK) in Kingston, I am very tired and bored of this ping-pong.
Are there any suggestions? Has anyone been down this route before with Nikon (UK)?