Moving Lights Definition

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Also known as... Intelligent Fixtures

Moving Lights - Description : Moving lights or intelligent fixtures were originally implemented in 1972, but the first computer-controlled stage lighting fixtures began to gain widespread acceptance in the concert industry in the early 1980's. As the digital age progressed, the cost of these fixtures was reduced and they slowly started being used in more 'traditional' theatrical environments. Intelligent fixtures are currently used in almost all major theatrical productions. Usually relying on compact arc lamps as a light source, these fixtures generally use stepper motors connected to varying internal devices to manipulate the light before it escapes the fixtures front lens. Examples of internal devices are: * Color wheels with dichroic lenses used to change the color of the beam. * Pattern wheels with gobos used to change the shape of the beam. * Shutters used to 'dim' or 'strobe' the output * Automated lens trains used to focus the beam. * Irises used to change the size of the beam. * Gate shutters to 'square off' the beam. * CMY color wheels using subtractive colors to change beam color by inserting dichroic glass filters with varying levels of color filtering into the optics chain. * Prisms The majority of these fixtures also use stepper motors to enable movement of the light fixtures output by either moving a mirror which reflects the beam, or by moving the entire fixture lens train. This allows the fixture to cover large areas by varying the X-Y coordinates of the beam. Higher performance fixtures use stepper motors for pan and tilt motion. Moving lights are controlled in many ways. Usually the fixtures are connected to a Lighting Console, which outputs a control signal. This control signal sends data to the fixture usually in one of three ways - Analog (which has largely been phased out), DMX (which is the industry standard control protocol), or Ethernet Control (which is still in development). The fixture then takes this signal and translates it into internal signals which are sent to the many stepper motors located inside.