Select Nikon cameras have an in-camera HDR mode so make sure to review your reference manual for complete details on setting your camera for HDR.
When shooting HDR (High Dynamic Range) with the D5100 DSLR camera for example, the camera automatically combines two exposures to form a single image that captures a wide range of tones, from shadows to highlights. The first exposure is darker (underexposed) and the second exposure brighter (overexposed). They are combined into one image that has a wider range of tones than can be captured in one exposure. HDR mode is only available with JPEG recording, not RAW (NEF) recording.
HDR is most effective when using Matrix metering, because the user is given the choice of choosing the difference in exposure value between the two shots from Auto, 1 EV, 2 EV or 3 EV. The camera automatically uses a 2 EV difference in exposure value when set to Center-Weighted or Spot metering.
After choosing the exposure value difference, the user is then given the choice of Smoothing (high, normal or low). Smoothing refers to the look of the composite HDR image. High and normal produce a more natural look, whereas low produces an image with a more surreal look.