An image sensor comprising: a pixel array including Bayer patterns, each of the Bayer patterns including a first pixel and a third pixel provided in a first diagonal direction and two second pixels provided in a second diagonal direction crossing the first diagonal direction, the first and second diagonal directions each being diagonal with respect to horizontal and vertical directions of the pixel array; and a first color separation element oriented to face the second pixels, wherein the first color separation element is configured to control light of a first wavelength band of incident light to travel in a first lateral direction of the color separation element toward the first pixel, to control light of a third wavelength band of the incident light to travel in a second lateral direction of the color separation element toward the third pixel, and to control light of a second wavelength band of the incident light to travel in a downward direction of the color separation element toward the second pixels, and wherein the pixel array includes a plurality of first pixel rows, in which a plurality of second pixels and a plurality of third pixels are alternately arranged in the horizontal direction, and a plurality of second pixel rows in which a plurality of first pixels and a plurality of second pixels are alternately arranged in the horizontal direction, the plurality of first pixel rows and the plurality of second pixel rows being alternately arranged in the vertical direction, characterised in that the first color separation element (133, 137) is oriented in the second diagonal direction to face downwardly both of the second pixels (1 10b) and not the first or third pixels of each Bayer pattern. a pixel array including Bayer patterns, each of the Bayer patterns including a first pixel and a third pixel provided in a first diagonal direction and two second pixels provided in a second diagonal direction crossing the first diagonal direction, the first and second diagonal directions each being diagonal with respect to horizontal and vertical directions of the pixel array; and a first color separation element oriented to face the second pixels, wherein the first color separation element is configured to control light of a first wavelength band of incident light to travel in a first lateral direction of the color separation element toward the first pixel, to control light of a third wavelength band of the incident light to travel in a second lateral direction of the color separation element toward the third pixel, and to control light of a second wavelength band of the incident light to travel in a downward direction of the color separation element toward the second pixels, and wherein the pixel array includes a plurality of first pixel rows, in which a plurality of second pixels and a plurality of third pixels are alternately arranged in the horizontal direction, and a plurality of second pixel rows in which a plurality of first pixels and a plurality of second pixels are alternately arranged in the horizontal direction, the plurality of first pixel rows and the plurality of second pixel rows being alternately arranged in the vertical direction, characterised in that the first color separation element (133, 137) is oriented in the second diagonal direction to face downwardly both of the second pixels (1 10b) and not the first or third pixels of each Bayer pattern.