Even a simple written letter is optical checked (proofread) before it is sent. br> Befor careless mistakes and unavoidable machine errors give the impression of a sloppy work, or defective parts delay following processes, each step must be checked! A simple manual visual inspection is not generally sufficient to detect all possible errors consistent and reliable. Also a automatic optical inspection is in many situations, for example by an unstable optical variance of the object, not possible, or the effort for parameterization and debugging is economically no advantage. Nevertheless, you have to check your products optical ! We have developed the "simply brilliant" Alternating Image Inspection with Quins easy !