Body elements

In addition to the USB and AV sockets, the D5100 offers sockets for an HDMI connector and an external microphone.

In keeping with the rest of the company's range the D5100 also features a connector for the GP1 GPS unit, which doubles as a socket for the MC-DC2 remote control.
The D5100 can utilize SD, SDHC or SDXC cards. It's worth getting hold of some fairly large, fast cards if you're hoping to make any great use of the camera's 1080p movie recording capabilities.
As with all the recent 'little' Nikons, the D5100 lacks a body-integral AF motor. This means it's unable to achieve autofocus with older (although still currently available) 'screw-drive' lenses.

Fortunately most popular entry-level lenses are now available with built-in focus motors.
Like the D3100 and D7000, the D5100 features a physical switch to activate Live View mode. Unlike these cameras, however, the D5100's live view switch is positioned on the top-plate, just to the right of the exposure mode dial. It isn't quite so easily accessible in this position.

There's also a new movie record button on the top plate, handily-positioned behind the shutter button. However its relationship to the live view lever is now a little less obvious than on the D7000 and D3100 (the record button does nothing unless you're in live view).
The D5000's slightly awkward bottom-hinged design is ditched, and the D5100's LCD screen is hinged in a more sensible, more 'traditional' way on the left hand side of the camera. This is designed to make it easier to use when shooting video, or with the camera on a tripod.

The screen can be extended as shown, and fully rotated. The display can also be stowed 'face in' to the camera for protection in tough environments or when the camera is stored.

The D5100's flash is fairly par for the course in terms of its power, but it is more than capable of providing enough illumination for close-range portraits and 'fill in' shots.

When raised, the flash sits high enough above the lens that there should be little risk of red-eye in portraits.

The D5100 boasts dual IR receivers - one built into the hand grip on the front of the camera, and another, positioned on the upper left of the camera's rear, just to the left of the viewfinder.

The (very dark red) receiver is visible here as a small dark oval to the left of the menu button. We've brightened this photograph to make the receiver more visible.
A welcome improvement over the D5000 (and an important differentiator compared to the D3100), the D5100's rear LCD screen is the same 921K dot unit that has impressed us so much on the D7000 and the higher-end Nikons.