An apparatus has an image sensing device, an instruction device for instructing to execute a plurality of image sensing operations with different image sensing times of the image sensing device, and a signal processing device for performing a first image sensing operation for making the image sensing device perform an image sensing operation in an exposure state to obtain a sensed image signal, and a second image sensing operation for making the image sensing device perform an image sensing operation in a non-exposure state to obtain a sensed image signal, and processing the sensed image signal obtained by the first image sensing operation by the sensed image signal obtained by the second image sensing operation. The signal processing device changes the second image sensing operation in response to the instruction of the instruction device.