Theatrical lighting in the context of "Dimmer"

Loie Fuller (/ˈloʊi/; born Marie Louise Fuller; January 15, 1862 – January 1, 1928), also known as Louie Fuller and Loïe Fuller, was an American dancer and a pioneer of modern dance and theatrical lighting techniques.

Auguste Rodin said of her, "Loie Fuller has paved the way for the art of the future."

A parabolic aluminized reflector lamp (PAR lamp or simply PAR) is a type of electric lamp that is widely used in commercial, residential, and transportation illumination. It produces a highly directional beam. Usage includes theatrical lighting, locomotive headlamps, aircraft landing lights, and residential and commercial recessed lights ("cans" in the United States).

Many PAR lamps are of the sealed beam variety, with a parabolic reflector, one or more filaments, and a glass or plastic lens sealed permanently together as a unit. Originally introduced for road vehicle headlamp service, sealed beams have since been applied elsewhere. Halogen sealed beam lamps incorporate a halogen lamp within a quartz or hard glass envelope.

An interference filter, dichroic filter, or thin-film filter is an optical filter that reflects some wavelengths (colors) of light and transmits others, with almost no absorption for all wavelengths of interest. An interference filter may be high-pass, low-pass, bandpass, or band-rejection. They are used in scientific applications, as well as in architectural and theatrical lighting.

An interference filter consists of multiple thin layers of dielectric material having different refractive indices. There may also be metallic layers. Interference filters are wavelength-selective by virtue of the interference effects that take place between the incident and reflected waves at the thin-film boundaries. The principle of operation is similar to a Fabry-Perot etalon.