Iris

1a. noun. A device with an adjustable circular aperture, used to reduce the size of the beam of an ERS, followspot, or hard-edged moving light.
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http://www.citytheatrical.com/Produc...51140&subDept=

See http://www.wilkes-iris.com/flashIris/iris.htm for a cool animation showing how irises work.

1b. verb. To open or close a followspot's iris on a cue. "Stand-by spot one to iris up to a head shot in five counts." "Spot two, iris out to include both performers when they come together."

2. A model of asymmetric-reflector cyc light, distributed under the brands Strand/Ianiro/Quartzcolor. Comparable to the Colortran FarCyc and Altman SkyCyc.
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