Nikon D6 Reference Manual page 962

Pixel Mapping
Pixel mapping checks and optimizes the camera image sensor.
If you notice unexpected bright spots appearing in pictures
taken with the camera, perform pixel mapping as described
below.
•
Use a fully-charged battery to prevent unexpected loss of
power.
•
Attach the lens cap (front cap) and close the eyepiece shutter
before performing pixel mapping.
1
Select [Pixel mapping] in the setup menu.
Turn the camera on, press the G button, and select [Pixel
mapping] in the setup menu.
2
Select [Start].
Pixel mapping will start. " 1 " appears in the top control
panel while the operation is in progress.
3
Turn the camera off when pixel mapping is
complete.
910 B The Setup Menu: Camera Setup
G button U B setup menu