If you don't want the camera to respond to changes in the light level (and you rarely do) then you want to ensure that you set AE Lock prior to shooting.
From the manual (don't have my D8000 yet) menu option g3 assigns the Live View function of the AE-L/AF-L button. You want to set that to AE Lock (Hold) so that exposure will remain locked after you press the button.
Figure out your pans before shooting, watch the light meter for exposure changes, dial in any exposure compensation that you need, lock the exposure in at the mid-point and reset camera position before calling "action!"
Thank you. My iPad typing was sloppy. Thanks for the suggestion, which worked.
What's happening is I set up a shot like normal. Say it's f8 at 1/100 of a second ready to go. If I click the shutter on the camera, the shot is f8 1/100. No surprise there.
But if I hit live view movie instead the f stop and shutter speed shift to other values. Same thing with iso. This is not moving the camera or pointing it in a new direction. You can see these settings change putting it in camera live view and then switching to movie live view.
I don't understand why the settings would change in the first place.
I think that's a function of the new D800 Live View - movie mode retains its own settings. The manual isn't clear on that, but the Nikon product information hints that it has its own exposure settings for movies. That would be most useful.
Try making changes in movie LV and then switch to photo and back. Do the previously set photo and movie settings stay the same between mode changes?