Rotate the auto mode selector lever to to take pictures in [P], [S], [A], and [M] modes.
Aperture can be adjusted using the lens aperture ring. If the lens is not equipped with an aperture ring, aperture can be adjusted using the [APERTURE SETTING] option in the shooting menu. Select an option other than [AUTO] to adjust aperture using the rear command dial.
Rotate the auto mode selector lever to [AUTO] to let the camera adjust settings to suit the subject.
In auto mode, you choose options for different subject types by rotating the rear command dial or using the SCENE POSITION option the shooting menu.