I have been using a D700 for several years, and the behavior of Live View is now intuitive to me. With the D800, things are quite different and perplexing.
With the D700, I rotate the dial to Lv. Then when I press the shutter release, the mirror goes up, and the monitor comes on. When I then press the shutter release half way, the monitor turns off, and when I fully press it the image is recorded, the info is displayed (thumbnail, histogram, etc.) for a few seconds, and when that clears the monitor returns to live view.
With the D800, when I press the Lv button, the mirror goes up and the monitor comes on (so far, so good). When I press the shutter release, the monitor goes off and the image is (I presume) recorded. There then follows a period of about 8 or 9 seconds when the monitor is off, the mirror remains up, and neither pressing the shutter release nor the Lv button elicits in any response. (In Cl or Ch mode I can take multiple images as long as the shutter release is pressed, but afterwords the same 8 or 9 second "pause" is once again in effect.) After the 8 or 9 second pause, the monitor comes on showing the info for a few seconds, followed by a return to live view.
I don't see anything in the manual about this. Is this the expected behavior?