The lens focus mode switch is set to <MF> If the lens focus mode switch is set to <MF>, the AF mode can be selected, but the autofocus will not operate. Set the lens focus mode switch to <AF>. An extender (sold separately) is used If a separately-sold extender is used together with a lens whose maximum lens aperture value is f / 5.6 or higher, the autofocus will not operate.