A method is provided for controlling an apparatus, the method comprising, detecting, as focus detection, a defocus amount based on a signal for a focus detection processing, controlling a focusing lens movement based on the defocus amount, and determining, as saturation determination, whether a subject to be subjected to the focus detection processing is a saturated subject. In a case where a state where a variation in the detected defocus amount of an image of the subject to be subjected to the focus detection processing or a variation in a moving amount of an imaging plane is smaller than a predetermined value continuously occurs the predetermined number of times or continues for a predetermined time duration, the subject to be subjected to the focus detection processing is determined to be a saturated subject in the saturation determination.