When a hand shake reducing mode has been set for shooting a subject, an exposure is controlled in accordance with a program diagram (solid line) B for the shake reducing mode, which is different from a program diagram (broken line) A for a normal mode. In a state where a shutter speed is set to less than “ 1/80”, two-pixel addition and/or four-pixel addition is executed on an imaging signal to amplify subject luminance, raising ISO sensitivity. A shutter speed set to fall in a high speed range reduces deterioration in image quality due to hand shake and/or subject movement during a shooting operation.