An imaging apparatus comprises an optical imaging system 110, an image sensor 101, and an image processor 103. The optical imaging system 110 has an aberration control element 103 for generating a predetermined aberration. The optical imaging system 110 forms an optical image. The image sensor 101 generates an image signal corresponding to the optical image. The image processor 103 performs image processing on the image signal so as to enhance a degraded image characteristic on the basis of the predetermined aberration. The aberration control element 112 causes a response of an optical transfer function of the optical imaging system 110 to be zero at a first spatial frequency. The first spatial frequency is below a Nyquist frequency of the image sensor 201.