1. An image processing apparatus comprising: an evaluation unit configured to evaluate validity of an imaging parameter acquired from image data outputted from an image capturing element that captures a subject image and generate an evaluation value of the imaging parameter; a generation unit configured to generate shake correction data by using shake data outputted from a shake detection unit; a control unit configured to control an image blur correction unit by using the shake correction data; a changing unit configured to cause, when photographing a moving image, an image blur correction performance of the image blur correction unit in a case of the evaluation value of the imaging parameter being close to a target value of the imaging parameter to be greater than the image blur correction performance of the image blur correction unit in a case of the evaluation value of the imaging parameter being far from the target value of the imaging parameter; and a recording unit configured to record a frame image whose image blur correction performance exceeds a predetermined threshold value as still image reproduction data.