An optical system includes a lens, a pupil relay, and an aperture stop positioned at a focal point of the lens between the lens and the pupil relay. The lens is configured to collect a plurality of light bundles. Each light bundle emanates from a field point of an object plane and has a center ray substantially parallel to an optical axis of the lens. The lens is configured to direct the center ray of each light bundle through the aperture stop and onto the pupil relay. The pupil relay is configured to image a plane of the aperture stop onto a sensor array.