The automotive parts contain precisely positioned, polished steel balls (mirror surface). About 0.01% of the products are not complete -usually one missing ball. Completeness check must be carried out for the whole production. A specialized vision system with a dedicated illumination source is required. The vision system is triggered when the item is under the camera moving on the production line. A collection of three images is acquired and processed in order to check if all balls are present. If an incomplete part is found, the line is stopped with a signal.