A mixed article sortation system and method of sorting the bulk flow of mixed articles being of various sizes and shapes to separate destinations includes at least two bulk flow singulators, each configured to receive a bulk flow of mixed articles and arrange the articles to respective first and second single-file flows. A microscope optical system has a mirror that changes the direction of the optical path by reflection and is located in the optical path between an objective lens of the microscope and an image to be observed. A second polymeric foam is coated with a braze composition.