An induction heating system having an induction source, a heating element heated from the induction source and a circuit energized by the induction source. Enjoyment for a plurality of spectators is enhanced. An image sensor unit may measure, collect, sense andor detect the aerial image in situthat is, the aerial image at the wafer plane produced, in part, by a production-type photomask andor by associated lithographic equipment used, or to be used, to manufacture of integrated circuits.