Nikon D6 Reference Manual page 951

Choosing a Default Fine-Tuning Value
1
Select [AF fine-tuning options] in the setup menu,
then highlight [Default] and press 2 .
2
Press 4 or 2 to fine-tune autofocus.
•
Choose from values between +20 and −20.
• The current value is shown by g , the previously-selected
value by j .
•
The larger the fine-tuning value, the farther the focal point
is from the lens; the smaller the value, the closer the focal
point.
3
Press J to save the new value.
B The Setup Menu: Camera Setup 899