An imaging system includes an optical unit that captures, from a scene, first images indifferent wavelength ranges when the scene is illuminated with not-structured light and second images of different wavelength ranges when the scene is illuminated with structured light. Thereby an imaging lens unit with longitudinal chromatic aberration is arranged between the scene and an imaging sensor unit. A depth processing unit may generate depth information on the basis of the second images by using optical triangulation. A sharpness processing unit uses the depth information to generate an output image by combining the first images. The optical unit of the imaging, system may be implemented in an endoscope.