Strange D800 behaviour / problem in Liveview
I just got my D800E back from a quick tune up at Nikon Canada. There wasn't really anything wrong with the camera, I just took it in to do a once over before the warranty is up and to tweak the focus points as my camera was one of the earlier D800E's made. There was no major repairs done, just a CLA.
However, upon receiving the camera I tried it with a few lenses to test focus and most of them worked fine in both live view and regular viewfinder mode. However I had problems with two of my lenses in live view mode only
1: My 50mm 1.8G would not achieve focus in live view (it would go to both ends of the focus scale then give up). It was also making strange noises in live view, so much so that I thought I had to turn it in for service as well. Autofocus on both lens and camera were on, problem persisted in both AF-C and AF-S modes
2: An even stranger problem with my 70-200 2.8 VR2 occurred. It would focus OK in live view (not great, it had difficulty locking on sometimes) but if I moved the camera suddenly to a different subject it would autofocus on that new subject without me needing to push the AF-On or shutter button. It wasn't a continuous focus, more like if I pressed AF-On it would focus on subject A, then if i moved the camera quickly to a different subject it would automatically focus on the new subject without me needing to press either AF-On or the shutter.(however it wouldn't confirm focus with a beep). Autofocus was on on both lens and camera.. problem persisted in both AF-C and AF-S modes. VR settings didn't make a difference.
3: My other lenses (Sigma art 35mm 1.4, nikon 70-300 VR2, some older D lenses) exhibited no such strange behavior
I was thinking I was going to have to make a trip back to Nikon service but I did a factory reset and now everything is behaving as it should. Is there some kind of mode that my camera was in that would explain the behavior? Or is it some kind of bug or maybe Nikon service put it in a special mode? Anyone else have this experience? Why would a factory reset resolve this issues?