Nikon D4S - Manual (Page 339)

317
U
Choose the function performed when the
B button is pressed.
a8: Assign AF-ON Button
G button
➜ A Custom Settings menu
Option Description
A AF-ON Pressing the B button initiates autofocus.
B AE/AF lock
Focus and exposure lock while the B button is
pressed.
C AE lock only Exposure locks while the B button is pressed.
D
AE lock (Reset
on release)
Exposure locks when the B button is pressed, and
remains locked until the button is pressed a second
time, the shutter is released, or the standby timer
expires.
E AE lock (Hold)
Exposure locks when the B button is pressed, and
remains locked until the button is pressed a second
time or the standby timer expires.
F AF lock only Focus locks while the B button is pressed.
None
No operation is performed when the B button is
pressed.