An image pickup apparatus includes an encoder which is arranged on an optical path of light incident from an object and which has a plurality of regions with first light transmittance and a plurality of regions with second light transmittance lower than the first light transmittance, a dispersive element which is arranged on an optical path of at least one part of light after passage through the encoder and which spatially shifts the at least one part of the light in accordance with wavelength, and at least one image pickup device which is arranged to receive light after passage through the dispersive element and light without passage through the dispersive element and which acquires a first image, in which light components for respective wavelengths spatially shifted by the dispersive element are superimposed, and a second image based on the light without passage through the dispersive element.