A color representation technique to be effectively applicable to a pixel shifted arrangement to realize high sensitivity and high resolution is provided by using a dipersive prism or diffraction.A dispersive element is provided for an image sensor in which photosensitive cells are arranged to be shifted from each other by a half pitch both horizontally and vertically. The dispersive element makes at least G rays fall straight down to a pixel right under itself and also makes either R rays or B rays incident on an adjacent pixel. Meanwhile, a photosensitive cell, for which no dispersive element is provided, receives directly incident light, too. Color information can be obtained by making computations on photoelectrically converted signals provided by these pixels.