Nikon D6 Reference Manual page 350

A
Movie Recording: Exposure Mode
•
If the subject is over- or under-exposed in mode P or S, exit and restart
live view or select mode A and adjust aperture.
•
The following exposure settings can be adjusted during filming:
Mode
P, S
A
M
1 Exposure control in mode S is the same as in mode P.
2 If [On] is selected for [Electronic VR] in the movie shooting menu
when ISO sensitivity is set to a value of from Hi 0.3 to Hi 5, ISO
sensitivity will be limited to 102400.
3 The upper limit for ISO sensitivity can be selected using the [ISO
sensitivity settings] > [Maximum sensitivity] item in the movie
shooting menu.
4 If [On] is selected for [ISO sensitivity settings] > [Auto ISO control
(mode M)] in the movie shooting menu, the upper limit for ISO
sensitivity can be selected using [Maximum sensitivity].
A
Adjusting White Balance During Movie Recording
White balance can be adjusted during movie recording by holding the
U button and rotating the main command dial. If [Auto] or
[Fluorescent] is selected, a sub-option can be selected by rotating the
sub-command dial.
298
Points to Note When Recording Movies
Aperture
1
—
4
4
Shutter speed
—
—
4
2
ISO sensitivity
3
—
3
—
4
4