1. An image-capturing apparatus comprising: (A) first polarizer that polarizes light from a subject; (B) a lens system that condenses light from the first polarizer; and (C) an image-capturing device array in which image-capturing devices are arranged in a two-dimensional matrix form in a first direction and a second direction perpendicular to the first direction, wherein a second polarizer is provided at a light incident side, and the image-capturing device array converts the light condensed by the lens system into an electric signal, wherein the first polarizer includes a first region and a second region arranged along the first direction, a polarization state of a first region transmission light having passed the first regions is different from a polarization state of a second region transmission light having passed the second regions, the second polarizer includes a plurality of third regions and fourth regions arranged alternately along the second direction and extending in the first direction, a polarization state of a third region transmission light having passed the third regions is different from a polarization state of a fourth region transmission light having passed the fourth regions, the first region transmission light passes the third regions and reaches the image-capturing device, and the second region transmission light passes the fourth region and reaches the image-capturing device, and thus, an image is captured to obtain a three-dimensional image in which a distance between a barycenter of the first region and a barycenter of the second region is a base line length of parallax between both eyes.