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How Cyc & Flood Lights Work

Symmetric Flood Light Optical System


Floodlights are the simplest of all theatre luminaires, comprising of little more than a lamp and reflector in a box that can be panned from side to side and tilted up and down.

As they have no lenses, the design characteristics of the floodlight are determined solely by the reflector and lamp type. Most modern theatre floodlights use linear quartz halogen lamps with a symmetrical half-pipe shaped reflector. The light is distributed equally above and below the horizontal axis of the lamp and, to a much lesser extent, equally to each side of the lamp.

Floodlights may be fitted with barndoors to provide some control of the edges of the light beam.

Asymmetric Flood Light Optical System

Cyclorama Lights

Cyc lights are a variation of the floodlight. They use a specially shaped asymmetric reflector in order to produce a light beam that spreads much further in one direction than the other relative to the horizontal axis of the lamp. This allows for a more even spread of light down the cyc cloth or back drop, or up the cloth if the cyc light is used as a groundrow. Like floodlights, there is also some light distributed to the sides of the lamp.

Cyc lights may be fitted with barndoors to provide some control of the edges of the light beam.

Modern cyc and flood lights are fitted with a safety-glass front to prevent hot fragments from failed lamps falling out of the luminaire and must not be operated without the safety glass in place. Another safety feature on any good quality flood or cyc light is a safety switch that automatically disconnects the power when the safety glass is not fully locked in the closed position.

Typical Uses

Cyc and flood lights are used for lighting the cyclorama, backcloths and for producing broad, relatively uncontrolled, washes of light over large areas. Groundrows are cyc lights placed on the ground at the bottom of the cyc cloth.