An invention that prepares in advance shading correction value for a plurality of discrete zoom positions is disclosed. For frame images sensed at zoom positions for which shading correction values are not provided, a correction value is obtained from shading correction values provided for zoom position closest to the zoom position in the telephoto direction and in the wide-angle direction at the time the image was sensed and shading correction performed, enabling proper shading correction to be performed on each frame image during zoom image sensing while economizing on memory capacity.