Body Elements

The D800's 36.3MP CMOS sensor has by far the greatest pixel count of any non medium format DSLR currently on the market. The ISO span is slightly wider than that of its predecessor the D700, at 100-6400, expandable up to ISO 25,600 (equivalent).
The D800's built-in flash can also act as a wireless trigger for up to two groups of Nikon Speedlight flashguns.
The D800 has a direct movie shooting button (with the red dot) for quick initiation of movie recording. The button is only active when the Live View switch on the back of the camera is set to the movie position - during normal stills shooting it does nothing.
The D800's drive mode dial is where you'll find the continuous low and high advance options, as well as a single-shot 'Quiet' mode, self-timer and mirror lock-up functions. A lock prevents accidental dial rotation, and we're pleased to see that the dial is taller and easier to grip than the same control on the D700.
The two function buttons on the front of the camera can be programmed to fulfil a wide range of different duties, including optical depth-of-field preview and activating an on-screen/in-viewfinder electronic horizon.

They can also be set to provide direct control of the aperture setting (in 1/8 EV steps) in video shooting mode.
The D800's live view control is inherited from the D4, and features two modes - still images and movie. In movie mode the view on the LCD is cropped to preview the field of view captured during video shooting. The 'Lv' button at the hub of the switch initiates live view.
New in the D800 is a USB 3.0 port, which shares space in the side of the camera with an HDMI out socket, a microphone socket, and a headphone jack for monitoring audio in movie mode.

In a small but welcome change compared to the D700, the rubber door that covers these ports is hinged, and will stay open until closed.
The D800 has twin memory card bays for SD and CF cards, with provision for simultaneous recording, as well as options for overflow or separate JPEG/Raw or still/video storage.
The D800's supplied battery is the EN-EL15 - the same battery used in the D7000 and the 1 V1. The D800 can also be powered by AA batteries, or by the EN-EL18 (supplied with the D4) via the optional MB-D12 battery grip. The D800 can capture around 900 images on a full charge, and around 60 minutes of live view/video operation.