I had a first issue with my D800 last week.
I was on a trip in Saint-Felicien zoo in Quebec.
In the afternoon, shooting animals with my new (5 months) Nikon 28-300mm lense, the aperture ring did not release correctly, leaving me with a strange dark and blured image.
It may also be a shutter problem or I don't know.
I tried changing the aperture, or going to live view with no effect.
I had to take a picture to have things back to normal. The picture was almost burnt out, almost white.
Next series of pictures were fine.
I first thought that was the lense, which I kind of hate actualy.
The next day, 7:00 AM, no rain, cold temperature but still warmer than 8 degres celcius, same problem with a Nikon 200-400mm f4 I have for a year now. I never had a problem with this lense on my D700 (and still had no problem with it when I used it later the same day). The issue was happening one every 10 or 15 pictures, for the whole safari (from 7 to 10:30)
My conclusion is that it is not a lense problem BUT a D800 problem... As the aperture ring is controled by a motor inside the D800, could this be the problem ?
The D800 was bought in april from B&H with official grip and 2 official Nikon batteries, almost fully charged when the problem arised.
I still have to do more testing at home now I have time to uderstand the problem better but does anybody out there had a similar problem ?