An imaging system includes an optical system, an optical element, a lighting, and an imaging device. The optical system has different focus positions for different wavelengths of light. The optical element extends depth of field of the optical system. The lighting irradiates an object with illumination light of a wavelength that is designated from among multiple wavelengths. The imaging device captures an image of the object that is irradiated with the illumination light and is formed by the optical system.