1. An imaging apparatus comprising: an imaging element that photoelectrically converts incident light so as to output an imaging signal; a stop that adjusts a light amount of the incident light; an apodization filter that is disposed on an optical path of the incident light; and an electric signal processing device configured for: performing photometry based on the imaging signal; storing a first program diagram in which an aperture value is fixed at an open aperture value in a case where an amount of exposure is equal to or less than a first amount of exposure, and a second program diagram in which an aperture value is fixed at an open aperture value in a case where the amount of exposure is equal to or less than a second amount of exposure, which is greater than the first amount of exposure; acquiring subject information based on the imaging signal; and selecting the second program diagram in a case where the apodization filter is disposed on the optical path and the subject information satisfies a first condition; selecting the first program diagram in a case where the apodization filter is not disposed on the optical path and in a case where the apodization filter is disposed on the optical path and the subject information does not satisfy the first condition; and determining one group of an imaging aperture value and an imaging shutter speed based on an amount of imaging exposure which is calculated from a photometric value obtained by the performing photometry.