1. An image pickup system comprising: a first illumination unit configured to emit light toward a subject at a first angle so as to illuminate the subject; a second illumination unit configured to emit light toward the subject at a second angle different from the first angle so as to illuminate the subject; an image pickup unit configured to capture an image of the subject; a control unit configured to cause only the first illumination unit to emit light at the time of image capturing of the subject performed by the image pickup unit so as to obtain a first captured image, and cause only the second illumination unit to emit light at the time of image capturing of the subject performed by the image pickup unit so as to obtain a second captured image; a division unit configured to divide each of the first captured image and the second captured image into a first area and a second area in accordance with at least any one of a hue condition, a saturation condition, and a luminance condition; and an image signal generation unit configured to generate an image signal for a specific area of the subject using a luminance signal of the first area of the first captured image and a color signal of the first area of the second captured image.