An apparatus and method that determines an appropriate light exposure condition to generate an appropriate synthesized image signal for an imaging scene for which an appropriate light exposure condition cannot be obtained by conventional techniques. The apparatus includes a determining unit for determining a plurality of light exposure conditions based on a histogram of the luminance distribution of an imaging scene, an imaging unit for imaging, plural times, the scene under the plurality of determined light exposure conditions, and generating first and second raw image signals, and an image synthesizing unit for synthesizing the first and second raw image signals using, as a boundary, a reference value in the first raw image signal to generate a synthesized image signal. The determining unit determines at least one light exposure condition of the light exposure conditions so that the reference value in the first raw image signal corresponds to the luminance value at the bottom of a ravine of the histogram of the luminance distribution of the scene.