Youre not alone. My d800 and my previous D300s both do this. It's annoying but I always assumed the first characteristic was because I touched something, though i am usually very careful not to, and the second usually seems to happen in low light and I assumed the camera was struggling to find something to lock on to. I assumed it was the camera letting me know that it was not going to be able to focus.. I always shoot in afs-c or afs- single or 9 point mode, though I can't say I know which of those 4 settings correlates with the AF point racing across the view finder phenomenon beyond the 9 or 1 point I selected. A half shutter press restores the camera to normalcy.

atilla ozturk said:
I was showing a friend the difference between DX and FX lenses on my D800E, I had a DX lens on when all of a sudden the auto focus stop working. I changed to an FX lens, still nothing, took the battery out, reset the camera checked everything still not working.
very frustrated I took the battery out and left it for a day. When I reattached the lens it worked but only for 15 min then it stopped again. Anybody have this problem?

And, now that we are here...make certain the battery is fully charged. Reset the camera as instructed on page 193 of the manual. Also, if by chance you are changing lenses with the camera on, this is prohibited. Always turn the power off when changing lenses, memory cards, etc.

Once camera is reset, check to make certain you have format set in the menus: Camera/Image Area/Auto DX crop "On"

If this does not help....let's see what others have to offer.

Maybe one of the focus "recognition" menus is on. This will cause the focus point to jump all over the place. And I never use this setting because I want to select my focus point myself. Check and see...

Hi Jeff,

The factory reset is a three part process on the D800, you have to hit your two-button reset (QUAL and Exposure compensation buttons) and reset your shooting menu and custom settings banks. But I've noticed it don't get rid of the copyright info. Anyways, I've tried that and gone one step further and had the camera replaced; with no success.

Simon

Try the old factory reset and see if it still does it. Not sure what it is on the D800 (That would mean I would have to actually go look at mine!)...

Later,
Jeff

Gareth said:
what camera did you have before the d800?

1) You MAY be activating the AF lock, either by bumping the lever onto the L position, or by hitting the AE-L AF-L button. Have a look at your settings.

2) You MAY be touching the Focus point selector with your nose when looking through the viewfinder.

I was using the D700 for the past few years, up until I got the D800 a month ago.

No, as stated, I'm not accidentally touching/pressing anything. And no he lock is not on.

what camera did you have before the d800?

1) You MAY be activating the AF lock, either by bumping the lever onto the L position, or by hitting the AE-L AF-L button. Have a look at your settings.

2) You MAY be touching the Focus point selector with your nose when looking through the viewfinder.

This is the second D800 I've had, the first one was serial #3002xx and the second is #3005xx, both have exhibited the following:

I haven't worked out a pattern to this yet but when in AF-S mode, I'm experiencing two separate issues.

1) At any given time it seems, I cannot move the focus point with the multi selector, it seems to get stuck/freezes. If I press the shutter release or turn the camera off and on again, that seems to allow me to move the focus point again.

2) At random, even though I'm in AF-S mode, the focus point races across the view finder, as if I kept my finger on the multi selector, and all of a sudden it stops, this could go on for several seconds and sometimes it won't stop unless I try to refocus on something else, but even when I do try and refocus, even that don't work at times so I turn the camera off and on again. I've had to point it at may different subjects while half-way pressing the shutter release to stop the focus point from racing across the screen.

At first I thought I just had an issue with that particular camera, but after getting the new one, I'm not sure anymore.

The lenses I've tested thus far are: Nikon 70-200G VR2, and Nikon 24-70G

At first I thought someway somehow I was touching something with my face, nose, fingers etc., but unfortunately not.

Has anyone experienced similar issues?

Thanks!