The roles played by each of the function buttons can be selected by pressing and holding the button. The default options are shown below:
Fn1/AE button (Photometry)
Fn2/AUTO button (Auto mode on/off)
Fn3 button (AF mode)
Fn4 button (Film simulation)
Fn5 button (Flash mode)
Fn6 button (Focus-frame selection)
Fn7/Fn button (Movie recording)