Nikon F6 Functions of the AF start and AE/AF-L buttons can be changed as following.

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Custom Setting Menu—continued
c3: AF-ON/AE-L x49, 58, 72
Functions of the AF start and AE/AF-L buttons can be changed as following.
Options:
Default: Functions remain unchanged
Switch function: Exchange each functions
Both AF-ON: Autofocus activated with AE/AF-L button
(function of AF start button unchanged)
Both AE-L: Exposure/focus locked with AF start button
(function of AE/AF-L button unchanged)
c4: Auto meter-off x18
After the shutter release button is pressed, the camera’s exposure meter
remains on for approx. 8 sec.(if no other operation is performed). This
duration can be changed to 4, 15 or 30 sec.
Options:
4 s
8 s
15 s
30 s
c5: Self-timer x82
At the default setting, the shutter is released 10 sec.after the shutter release
button is fully depressed.This duration can be changed to 2, 5 or 20 sec.
Options:
2 s
5 s
10 s
20 s
•Note that with longer auto meter-off duration, batteries are exhausted faster and
usable number of film roll per battery decreases.
•Setting in “c2: AE-L/AF-L” (x99) is also active in this
option. For example, if “Both AE-L” is selected and “AF
lock only” is set in “c2: AE-L/AF-L”, only focus is locked by
pressing either AE/AF-L or AF start button.
P930_En 04.10.19 7:19 PM Page 100