Nikon D300 Complete Manual page 577

Preview
FV lock
AE/AF lock
AE lock only
AE lock (Reset)
AE lock (Hold)
AF lock only
Flash off
Bracketing burst
Thom Hogan's Complete Guide to the Nikon D300
The Fn button acts as a DOF Preview
button
The flash is preflashed once and the
value for flash locked when the Fn
button is pressed; a second press
cancels FV lock [default]
Holding the Fn button locks both
exposure and focus
Holding the Fn button locks exposure
Pressing the Fn button locks
exposure, but releases the lock if you
press the button again, the meter
times out, or you press the shutter
release
Pressing the Fn button locks exposure
until the meter times out or you press
the button a second time
Holding the Fn button locks focus
Flash is disabled while the button is
held
If held at start of a bracketing
sequence, all shots in the sequence
are taken immediately (with one
shutter release press); in continuous
release shooting method, multiple
sequences of a bracketing set will be
V1.02
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