A followspot, sometimes known as a spotlight, is a powerful stage light which can be controlled by a human spotlight operatorto "follow" actors around the stage. Followspots are commonly used in musical theatre and opera to highlight the stars of a performance, but might find use in a drama to briefly focus the audience's attention on a hand-motion or a prop (such as in a murder mystery or thriller). They are also used in sports venues, as well as many other applications. Followspots are usually located in the Front of House position in the theatre.
Most followspots use arc lampsor the more powerful xenon arc lampsto produce a bright, white light. Carbon arc lamp spots were common until the 1990s, using the arc between carbon rods as their light source. These follow spots required special installations that include high volume ventilation due to the hazardous fumes produced by the carbon arc. The current generation, xenon, has extremely high internal pressure in the lamp and thus has its own safety concerns.
A manual device to change the intensity of the beam, especially when an HID source which can not be electronically dimmed is used
An "iris" to adjust the size of the spot/angle of the beam
A color magazine or "boomerang" consisting of several gelframes which can be swung in front of the beam
Some sort of physical sightto assist in aiming is sometimes added onto the lamp by the operator.
Some followspots can be fitted with colourchangers to colour the beam, and/or gobo holders to create a variety of effects. Most followspots can be fitted with colour gels.
