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; and an image processing unit configured to associate the first captured image with the second captured image.