The lighting advisor is a Prolog program which is intended to suggest possible lighting and viewing configurations to an engineer faced with the task of designing a machine vision system for industrial inspection. The program asks a series of simple questions about the object that is to be inspected and the type of feature, or defect, which is to be highlighted. The program then displays a line drawing, which shows a sketch of the recommended optical configuration. Further questions are then posed and other diagrams are displayed. Each of the diagrams is accompanied by explanatory notes, but these will only be displayed if desired by the user. These notes describe the type of equipment required, how to set up the optical system and, where appropriate, a reference to the technical literature.