This chapter discusses the components of a luminaire based on the functions that each provides to a unit, introduces photometrics, and examines the principal luminaires associated with entertainment lighting. It also examines the means by which we control or manipulate light. The chapter explores the primary optical components that are used to control the light once it has been produced by a light source. In order to maintain maximum light output from a luminaire, several maintenance procedures should be performed on a regular basis. The ellipsoidal reflector spotlight (ERS) is the most extensively used spotlight in the world. The optics of this luminaire are superior to most other spotlights and produce a crisp, evenly distributed pool of light. Striplights are a unique luminaire in that they are one of the few fixtures that make use of multiple lamps. Probably the most desired option that lighting designers want from their luminaires is the ability to redirect a light's focus.