4 main lighting instruments in theatrical lighting?

Answer 1

Four types of incandescent conventional fixtures in theatrical lighting are ERS "Lekos", parabolic reflector can "parcans", Fresnel, and parcan/Fresnel hybrids "Parnels". Other types of commonly used lights recently developed are color mixing LEDs and intelligent moving lights (which typically use LED and/or arc-ing lamps).

We also use flashlights. :)