Nikon D3X User Manual page 208

To use Active D-Lighting:
1
Select [Active D-Lighting].
In the shooting menu (pg. 290),
highlight [Active D-Lighting]
and press 2.
2
Choose an option.
Highlight an option and
press J. Choose [Auto] to let
the camera automatically select
[High], [Normal], or [Low]
according to shooting
conditions.
J
D
Active D-Lighting
When Active D-Lighting is on, the capacity of the memory buffer drops
and additional time is required to record images (pg. 429). Matrix
metering is recommended (pg. 110). Although exposure is in fact reduced
to prevent loss of detail in highlights and shadows, highlights,
underexposed areas, and mid-tones are automatically adjusted to prevent
the resulting photograph from being underexposed. The [Brightness] and
[Contrast] Picture Control settings (pg. 167) can not be adjusted while
Active D-Lighting is in effect. Noise, distortion, or banding may be visible
at high ISO sensitivities. In exposure mode h, an Active D-Lighting setting
of [Auto] is equivalent to [Normal].
D
"Active D-Lighting" versus "D-Lighting"
The [Active D-Lighting] option in the shooting menu adjusts exposure
before shooting to optimize the dynamic range, while the [D-Lighting]
option in the retouch menu optimizes dynamic range in images after
shooting.
182