Intelligent lighting refers to stage lighting that has automated or mechanical abilities beyond those of traditional, stationary illumination. Although the most advanced intelligent lights can produce extraordinarily complex effects, the intelligence lies with the programmer of the show rather than the instruments or the lighting operator. For this reason, intelligent lighting is also known as automated lighting, moving lights or moving heads.
Features
An automated light, properly called a luminaire, fixture (or sometimes moving head), is a versatile and multi-function instrument designed to replace multiple conventional, non-moving lights. Depending on the venue and application, automated luminaires can be a versatile and economical addition to a stock of traditional lights because, with proper programming, they can swiftly alter many aspects of their optics, changing the “personality” of the light very quickly. Lighting is typically pre-programmed and played back using only simple commands, although moving heads can be controlled “live” if the operator is sufficiently experienced.
Control
Moving lights are controlled in many ways. Usually the fixtures are connected to a Lighting control console, which outputs a control signal. This control signal sends data to the fixture usually in one of three ways: Analogue (which has largely been phased out), DMX which stand's for "Digital Multiplex" (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.
The vast majority of moving heads are controlled using the DMX protocol, usually using dedicated twisted pair, shielded cable with 5-pin XLR connectors at the ends. Each fixture is assigned a block of DMX channels in one of the venue's DMX universes (a self-contained set of cables and fixtures which can operate a maximum of 512 individual channels). The central lighting desk transmits data on these channels which the intelligent fixture interprets as value settings for each of its many variables, including color, pattern, focus, prism, pan (horizontal swing), tilt (vertical swing), rotation speed, and animation.
Since moving heads did not attain prominence until DMX's predecessor, analogue, had passed the zenith of its popularity, very few moving heads use analogue control (this is also due to crippling restrictions on bandwidth, data transfer speeds and potential inaccuracy). Some of the most modern intelligent fixtures use RJ-45 or Ethernet cabling for data transfer, due to the increased bandwidth available to control increasingly complicated effects. Using the new Ethernet technology, control surfaces are now able to control a much larger array of automated fixtures. Because many devices can be connected to a single RJ-45 network, these devices have the ability to not only listen to a control signal from a lighting control board, but have the ability to transmit information back to the control board and other entities on the network. Now, it is possible for a fixture to self-diagnose any problems, announce itself on a network, or accept setting changes from any place on the network, making obsolete older versions of the system that only had one central brain, the lighting control board. Because RJ-45 (and equivalent technologies) use bidirectional digital communication, bit-checking abilities allow for lighting control networks to safely operate devices that can interfere with human safety (pyrotechnic devices, rigging mechanisms, etc.).
Moving lights are much more difficult to program than their analogue cousins because they have more attributes per fixture that must be controlled. A simple conventional lighting fixture uses only one channel of control per unit: intensity. Everything else that the light must do is pre-set by human hands (colour, position, focus, etc.) An automated lighting fixture can have as many as 30 of these control channels. A slew of products are available on the market to allow operators and programmers to easily control all of these channels on multiple fixtures. Lighting boards are still the most common control mechanism, but many programmers use computer software to do the job. Software is now available that provides a rendered preview of the output produced by the rig once fixtures are connected to the program or console. This allows programmers to work on their show before ever entering the theater and know what to expect when the lights are connected to their controller. These products usually feature some method of converting a computer's USB output to a DMX output.
The latest generation of moving heads are integrating digital projection capabilities, creating a real convergence between lighting and video projection. These new generation of heads do not only require intensity, position and focus control, but will require video content control as well.
While it is true that moving lights have, in a sense "revolutionized" the world of concert and other event lighting, to call these fixtures "intelligent" can be offensive to some people. In fact, not every person involved in the music production business feels that moving lights are intelligent, necessary or even desirable at all. While this type of technology can be used very effectively, there are many instances in which it simply distracts an audience from the lack of musical content coming from the stage. In this case, to call this lighting "intelligent" can be the source of much confusion.
Usage
Intelligent lights (now commonly referred to as automated or moving heads), can be used wherever there is a need for powerful lighting which must be capable of rapid and extreme changes of mood and effects. Moving heads would, therefore, be inappropriate in a setting which does not require strong lighting (such as a home) or where the “quality” of the light required does not vary excessively (although it may need to be very strong for a venue like a stadium). Naturally, there are exceptions to this rule, most notably the use of large numbers of moving heads for international sporting events, such as the Commonwealth Games or Olympic Games, where many thousands of separate automated fixtures are often used to light the opening and closing ceremonies. The 2008 Summer Olympics, in Beijing, had a rig of around 2,300 intelligent fixtures which is "the largest single automated lighting system ever assembled for a single event"[10]
Usually, however, the use of intelligent lights is confined to theatre, concerts and nightclubs, where the versatility of these fixtures can be utilised to its best extent. In these applications, the uses of fixtures can be informally grouped into two categories: active and passive (although these are not standardised terms).
Passive use of automated lighting involves utilizing their versatility to perform tasks which would otherwise require many conventional lights to accomplish. For example, six to eight moving heads can create a textured blue “night” effect on the stage floor while applying amber light to the actors during one scene - this can create a sensation of dusk or night. At the flick of a switch, the fixture can change to an animated red “fire” effect for the next scene. Attempting this transition with traditional lighting fixtures could require as many as thirty instruments. In this circumstance, the automated fixtures are not doing anything that could not be achieved using conventional fixtures, but they dramatically reduce the number of lights needed in a rig. Other features of automated fixtures, such as rotating gobos, are also possible with conventional fixtures, but are much easier to produce with intelligent fixtures.
Active use of automated lights, suggests that the luminaire is used to perform tasks which would otherwise require human involvement, or be simply impossible with conventional fixtures. For instance, a number of moving heads producing tightly focused, pure white beams straight down onto the stage will produce a fantastic effect reminiscent of searchlights from a helicopter (especially if a smoke machine or hazer is used to make the beams visible). To recreate such an effect without intelligent lights would require at least one human operator seated directly above the stage with a followspot, which would generally be considered to be too expensive for such a small effect.
Moving head fixtures are often divided into spot and wash lights. They vary in use and functions, but many companies offer profile and wash versions of the same model of light. Profile lights generally contain features like gobos and prisms, whereas wash lights have simpler optics and a wider beam aperture resulting in wider beam angle, which may be altered by internal lenses or “frost effects”. Wash lights are more likely to have CMY colour mixing although it is common for high-end spot lights to have such features too. Spot units are generally used for their beam effect (usually through smoke or haze) and the ability to project texture, whereas wash lights tend to be used for providing a stage wash.
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