Wide angled optical system

A wide-angle optical system (10, 60) for the infrared spectral region with an evaluation unit, particularly a detector (16), with a stop (22) disposed in front of the evaluation unit, has, in direction from an object side to an image side, a lens system with a primary lens system (12) and a secondary lens system (14). An intermediate image plane is located between the primary lens system (12) and the secondary lens system (14). An entrance pupil (26) is located on the object side of the primary lens system (12), which is the real image of the stop (22). An exit pupil (24), located on the image side of the secondary lens system (14), which coincides with the stop (22).