1. An image pickup apparatus comprising: an image pickup optical system that forms an optical image of an object to be photographed; an image pickup sensor that receives the formed optical image, converts the optical image to an electrical image signal and outputs the electrical image signal; a camera shake correcting section that corrects a shake of the optical image caused by a motion of the image pickup apparatus; a motion detecting section that is configured to detect a motion of the optical image of the object caused by a motion of the object, wherein the motion detecting section detects the motion of the optical image based on images captured when the camera shake correcting section is correcting the shake of the optical image caused by the motion of the image pickup apparatus; and a control section that is configured to control an exposure time according to the detected motion of the optical image of the object.