H ANGING The plot AND F OCUSING THE L IGHTS Hanging the lights is done to specifications laid down by a designer, who should provide a light plot. Most of the time, this is a scale representation of the theatre and its lighting positions, showing the lighting equipment types in their proper locations. Occasionally, plots are more like a schematic drawing, and are not to scale. Computer-aided-design (CAD) plots are often used. CAD programs came into their own early on in lighting design, because they are really good at keeping track of all the numbers used for dimmers, channels, circuits, gel colors, and the like. It is also much easier to add and delete lights on the computer and then print out a new plot than it is to do any sort of hand-drafting. However, it should be noted that there were many very artistically satisfying lighting designs created in advance of CAD technology. The computer makes the paperwork a lot easier to put together, but doesn't make anything more artistic. The art part must come from an actual human being. numbers, and instrument numbers. This is just like the legend used on a road map to indicate types of roads, hospitals, airports, and so on. Front-of-house positions should be labeled, as well as the battens being used as electrics. Electrics should have an indication of their trim height.