Nikon D300 User Manual page 404

▪ AE lock (Reset on release)** – Enabling this function
causes AE
when the Selected button is pressed once. It stays locked
until you press the Selected button again. Releasing the
shutter resets the
button a second time does. Setting this function disables
other functionality in the D300(S). Please see the** note
at the end of this section.
▪ AE lock (Hold)** – Enabling this function causes
(exposure) to lock on the last meter reading when the
Selected button is pressed once. It stays locked until you
press the Selected button again. In other words, the
Selected button toggles
lock (Reset on release)
does not reset the AE lock hold. You must press the
Selected button again to release
function disables other functionality in the D300(S).
Please see the** note at the end of this section.
▪ AF lock only – When set, this function locks the AF
system (focus) on the last autofocus reading while you
hold down the Selected button.
▪ AF-ON (Assign AE-L/AF-L button
AE-L/AF-L button press
button duplicates the functionality of the
and will initiate autofocus.
the other two buttons
appear in their lists of functions.
▪ Flash off – This is a temporary way to disable the flash
for when you want to leave your flash turned on and still
(exposure) to lock on the last meter reading
AE Lock
AE
except that releasing the shutter
to AF-ON, then the
(Fn
404
just like pressing the Selected
lock. This is similar to
AE lock. Setting this
only) – If you set
AF-ON cannot be assigned to
and Preview). It doesn't even
AE
AE
AE-L/AF-L
AF-ON button