LED stage lighting instruments are stage lighting instruments that use light-emitting diode

Light-emitting diode

A light-emitting diode is a semiconductor light source. LEDs are used as indicator lamps in many devices and are increasingly used for other lighting...

s (LEDs) as a light source. LED instruments are an alternative to traditional stage lighting instruments which use halogen lamp

Halogen lamp

A halogen lamp, also known as a tungsten halogen lamp, is an incandescent lamp with a tungsten filament contained within an inert gas and a small amount of a halogen such as iodine or bromine. The chemical halogen cycle redeposits evaporated tungsten back on to the filament, extending the life of...

 or high-intensity discharge lamp

High-intensity discharge lamp

High-intensity discharge lamps are a type of electrical lamp which produces light by means of an electric arc between tungsten electrodes housed inside a translucent or transparent fused quartz or fused alumina arc tube. This tube is filled with both gas and metal salts. The gas facilitates the...

s. Like other LED instruments, they have high light output with lower power consumption.

Types of LED instruments

LED stage lights come in three main types. PAR cans

Parabolic aluminized reflector light

A parabolic aluminized reflector lamp is a type of electric lamp that is widely used in commercial, residential, and transportation illumination. Usage includes locomotive headlamps, aircraft landing lights, and residential and commercial recessed lights...

, striplight

Striplight

A striplight is a multi-circuit stage lighting instrument. Striplights are one of the most basic types of lighting fixtures available. They usually consist of row of lamps. A single striplight is usually wired internally into either 3 or 4 circuits. Each internal circuit consists of several...

s and 'moving head' types. In LED PAR cans, a round printed circuit board with LEDs mounted on is used in place of a PAR lamp. Moving head types can either be a bank of LEDs mounted on a yoke

Yoke

A yoke is a wooden beam, normally used between a pair of oxen or other animals to enable them to pull together on a load when working in pairs, as oxen usually do; some yokes are fitted to individual animals. There are several types of yoke, used in different cultures, and for different types of oxen...

 or more conventional moving head lights with the bulb replaced with an LED bank.

Uses

LED instruments can and have been used to replace any conventional lighting fixture, and some shows, such as Radiohead

Radiohead

Radiohead are an English rock band from Abingdon, Oxfordshire, formed in 1985. The band consists of Thom Yorke , Jonny Greenwood , Ed O'Brien , Colin Greenwood and Phil Selway .Radiohead released their debut single "Creep" in 1992...

's recent tour, have used only LED lighting instruments.. However, most shows use LEDs only for lighting cycloramas

Cyclorama (theater)

A cyclorama is a large curtain or wall, often concave, positioned at the back of the stage area. It was popularized in the German theater of the 19th century and continues in common usage today in theaters throughout the world...

, or as top, side or back light. They can also be used as 'audience blinders' (lights pointed directly at the audience from a low angle).

Advantages

LED instruments can contain a number of different coloured LEDs, often Red, Green and Blue, and different light output colours can be achieved by adjusting the intensity of each LED color group. LED instruments should have a long service life relative to other options, without the expense of colour gel or replacement lamps.

LED instruments are increasingly used for live music events, most notably festivals where they are more visible than conventional lighting under daylight. LED instruments were prominently used for the 'live earth' festival as they are regarded as more environmentally friendly as fixture for fixture they use far less power than other lighting.

Another advantage of LED instruments is that they can be controlled directly using DMX and do not require additional dimmers; the intensity of the LEDs being adjusted by circuitry onboard the fixture. Because of their low power consumption several units can be daisy chained to one power supply.

Due to low heat output, LED instruments can be used in areas where the high amount of heat conventional stage fixtures put off would not be ideal. For this reason, LED instruments are used to light ice sculptures, especially when lighting the sculptures from within.

Disadvantages

‎
A comparison of two American DJ 64 LED Pro fixtures vs a single PAR-54 GE 300 watt medium flood incandescent.

LED instruments cannot be used to create a hard edged beam, which is needed for gobo

Gobo (lighting)

A gobo derived from "Go Between" or Goes Before Optics -originally used on film sets, is a physical template slotted inside, or placed in front of, a lighting source, used to control the shape of emitted light....

s and other effects which require the use of an ellipsoidal reflector spotlight. Because color mixing is done using three or more colors of LEDs, mixed colors will have multiple edges to shadows where different colors are showing, however Elation Professional has introduced instruments that group three LEDs behind a single lens to make the multiple shadow lines less noticeable. Because of the multiple light sources in the fixture, most shadows are a soft edge as well.

As of 2008, the output intensity of LED lighting is still unable to match the luminous power of traditional incandescent lamps. A 300 watt medium-spot GE PAR-54 easily outshines a PAR-64 RGB LED Pro fixture from American DJ, which is one of the brightest LED fixtures available in 2008. The LED output spectrum is additionally very cold (blue) compared to the warm (yellow/red) of the incandescent.

Several times as many LED fixtures may be needed to match the brightness of a traditional fixture of similar size. But LED fixtures also currently cost several times more than a traditional incandescent fixture, greatly increasing the expense to use LED fixtures at the same brightness level as with traditional incandescents.