Nikon D6 Reference Manual page 879

d5: Exposure Delay Mode
In situations where the slightest camera movement can blur
pictures, shutter release can be delayed by from about 0.2 to
3 seconds after the mirror is raised.
d6: Electronic Front-Curtain Shutter
Enable or disable the electronic front-curtain shutter. Enabling
the electronic front-curtain shutter helps reduce blur caused by
camera shake. The electronic front-curtain shutter is available in
Q and M release modes.
UP
Option
[Enable]
[Disable]
G button U A Custom Settings menu
G button U A Custom Settings menu
Enable the electronic front-curtain shutter.
Use the mechanical shutter.
A Custom Settings: Fine-Tuning Camera Settings
Description
827