Ellipsoidal Lights, also known as Ellipsoidal Reflector Spotlights (ERS) or Lekos, are precision lighting fixtures used in theatre, concerts, and live performances. They produce a focused, highly controllable beam of light with sharp edges, making them ideal for spotlighting specific areas or objects on stage. Ellipsoidal lights often feature adjustable shutters to shape the beam and can accommodate gobos to project patterns or images. Their ability to focus light with high accuracy and their flexibility in controlling beam size and shape make them essential for detailed, dramatic lighting designs in professional stage productions.