In an image pickup system, illumination light emitted by a light emission part is collected and reflected by an optical member and is distributed to a predetermined area. This light distribution to the predetermined area permits a constituent point farther away from the light emission part to receive illumination light having a greater intensity of light being equal to or greater than a predetermined reference value. The image pickup system thus distributing the illumination light enables the intensity of light incident on each pixel constituting an image pickup predetermined area to be equal to or greater than an intensity reference value while enabling the distribution of the intensity of light incident on each pixel constituting the image pickup predetermined area to be within a first reference range.