The roles played by each of the seven function buttons can be selected by pressing and holding the button. The default options are shown below:
Fn1 button (movie recording)
Fn2 button (AF mode)
Fn3 button (bracketing and advanced filters)
Fn4 button (film simulation)
Fn5 button (flash mode)
Fn6 button (focus-frame selection)
Fn7 button (wireless options)