I've been using my D810 for a few months now without any problems. However, yesterday I fancied trying my hand at time lapse photography. Problem is that on the shooting menu, both the time lapse and interval timer shooter are greyed-out, so I can't access them. I looked in the manual, and it tells me that they won't work if the camera has various settings active (HDR, live view, bracketing etc.) None of these settings are active, so what's the problem? Anybody have any ideas? I have a D7100 and it works fine on that. Do I have a fault on the D810?