Stage lighting
Overview
 
Modern stage lighting is a flexible tool
Tool
A tool is a device that can be used to produce an item or achieve a task, but that is not consumed in the process. Informally the word is also used to describe a procedure or process with a specific purpose. Tools that are used in particular fields or activities may have different designations such...

 in the production of theatre
Theatre
Theatre is a collaborative form of fine art that uses live performers to present the experience of a real or imagined event before a live audience in a specific place. The performers may communicate this experience to the audience through combinations of gesture, speech, song, music or dance...

, dance
Dance
Dance is an art form that generally refers to movement of the body, usually rhythmic and to music, used as a form of expression, social interaction or presented in a spiritual or performance setting....

, opera
Opera
Opera is an art form in which singers and musicians perform a dramatic work combining text and musical score, usually in a theatrical setting. Opera incorporates many of the elements of spoken theatre, such as acting, scenery, and costumes and sometimes includes dance...

 and other performance
Performance
A performance, in performing arts, generally comprises an event in which a performer or group of performers behave in a particular way for another group of people, the audience. Choral music and ballet are examples. Usually the performers participate in rehearsals beforehand. Afterwards audience...

 arts. Several different types of stage lighting instrument
Stage lighting instrument
Stage lighting instruments are used in stage lighting to illuminate theatrical productions, concerts, and other performances taking place in live performance venues. They are also used to light television studios and sound stages.Many stagecraft terms vary between the United States and the United...

s are used in the pursuit of the various principles or goals of lighting. Stage lighting has grown considerably in recent years partially due to improved technical equipment and a higher interest from young people. A lot of stage lights today have the ability to change colour within 0.03 seconds.
Stage lighting has several functions, although to allow for artistic effect, no hard and fast rules can ever be applied.
Encyclopedia
Modern stage lighting is a flexible tool
Tool
A tool is a device that can be used to produce an item or achieve a task, but that is not consumed in the process. Informally the word is also used to describe a procedure or process with a specific purpose. Tools that are used in particular fields or activities may have different designations such...

 in the production of theatre
Theatre
Theatre is a collaborative form of fine art that uses live performers to present the experience of a real or imagined event before a live audience in a specific place. The performers may communicate this experience to the audience through combinations of gesture, speech, song, music or dance...

, dance
Dance
Dance is an art form that generally refers to movement of the body, usually rhythmic and to music, used as a form of expression, social interaction or presented in a spiritual or performance setting....

, opera
Opera
Opera is an art form in which singers and musicians perform a dramatic work combining text and musical score, usually in a theatrical setting. Opera incorporates many of the elements of spoken theatre, such as acting, scenery, and costumes and sometimes includes dance...

 and other performance
Performance
A performance, in performing arts, generally comprises an event in which a performer or group of performers behave in a particular way for another group of people, the audience. Choral music and ballet are examples. Usually the performers participate in rehearsals beforehand. Afterwards audience...

 arts. Several different types of stage lighting instrument
Stage lighting instrument
Stage lighting instruments are used in stage lighting to illuminate theatrical productions, concerts, and other performances taking place in live performance venues. They are also used to light television studios and sound stages.Many stagecraft terms vary between the United States and the United...

s are used in the pursuit of the various principles or goals of lighting. Stage lighting has grown considerably in recent years partially due to improved technical equipment and a higher interest from young people. A lot of stage lights today have the ability to change colour within 0.03 seconds.

Functions of lighting

Stage lighting has several functions, although to allow for artistic effect, no hard and fast rules can ever be applied. The functions of lighting include:
  • Illumination: The simple ability to see what is occurring on stage. Any lighting design will be ineffective if the viewers cannot see the characters, unless this is the explicit intent.

  • Revelation of form: Altering the perception of shapes onstage, particularly three-dimensional stage elements.

  • Focus: Directing the audience's attention to an area of the stage or distracting them from another.

  • Mood: Setting the tone of a scene. Harsh red light has a totally different effect than soft lavender light.

  • Location and time of day: Establishing or altering position in time and space. Blues can suggest night time while orange and red can suggest a sunrise or sunset. Use of mechanical filters
    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....

     ("gobos") to project sky scenes, the moon, etc.

  • Projection/stage elements: Lighting may be used to project scenery or to act as scenery onstage.

  • Plot(script): A lighting event may trigger or advance the action onstage.

  • Composition: Lighting may be used to show only the areas of the stage which the designer wants the audience to see, and to "paint a picture".


While Lighting Design is an art form, and thus no one way is the only way, there is a modern movement that simply states that the Lighting Design helps to create the environment in which the action take place while supporting the style of the piece. "Mood" is arguable while the environment is essential.

Qualities in lighting

The four main qualities or properties of lighting are intensity, color, pattern and focus.

Intensity

This is measured in lux
Lux
The lux is the SI unit of illuminance and luminous emittance, measuring luminous flux per unit area. It is used in photometry as a measure of the intensity, as perceived by the human eye, of light that hits or passes through a surface...

, lumen
Lumen (unit)
The lumen is the SI derived unit of luminous flux, a measure of the total "amount" of visible light emitted by a source. Luminous flux differs from power in that luminous flux measurements reflect the varying sensitivity of the human eye to different wavelengths of light, while radiant flux...

s and foot-candle
Foot-candle
A foot-candle is a non-SI unit of illuminance or light intensity widely used in photography, film, television, conservation lighting, and the lighting industry...

s. For any given luminaire (lighting instrument or fixture), this depends upon the power of the lamp, the design of the instrument (and its corresponding efficiency), the presence or absence of colour gels or mechanical filter
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, distance from the area to be lit and the beam or field angle of the fixture, the colour and substance to be lit, and the neuro-optics of the total scene (that is, the relative contrasts to other regions of illumination).

Color

Color temperature is measured in kelvin
Kelvin
The kelvin is a unit of measurement for temperature. It is one of the seven base units in the International System of Units and is assigned the unit symbol K. The Kelvin scale is an absolute, thermodynamic temperature scale using as its null point absolute zero, the temperature at which all...

s, and gel colors are organized by several different systems maintained by the colour manufacturing companies. The apparent color of a light is determined largely by the gel color given it, but also in part by the power level the lamp is being run at and the color of material it is to light. As the percentage of full power a lamp is being run at drops, the tungsten
Tungsten
Tungsten , also known as wolfram , is a chemical element with the chemical symbol W and atomic number 74.A hard, rare metal under standard conditions when uncombined, tungsten is found naturally on Earth only in chemical compounds. It was identified as a new element in 1781, and first isolated as...

 filament in the bulb glows orange instead of more nearly white. This is known as amber drift or amber shift. Thus a 1000-watt instrument at 50% will appear far more orange than a 500-watt instrument at full.

LED fixtures create color through additive color mixing with red, green, and blue LEDs at different intensities. This type of color mixing is also used frequently with borderlights
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...

 and cyclorama lights to create different colors on stage and on the cyclorama.

Another form of color mixing is CMY, or subtractive color mixing. Variable density cyan, magenta and yellow dichroic filters are inserted into the optical path of the lighting fixture at different percentages of transmission to subtractively mix different colors, in a manner that is similar to the way ink jet printers can create a range of colors by mixing varied densities of cyan, magenta and yellow inks. In an effort to extend the range (gamut) of subtractive color mixing systems, some manufacturers add an additional green or amber ("CTO" color correction) filter to the basic CMY system.

Pattern

|width="105px" | >

|-
| colspan="2" align="center" width="210px" | A gobo of this shape in a fixture with a red gel would produce a pattern like the one shown to the right.

Pattern refers to the shape, quality and evenness of a lamp's output. The pattern of light an instrument makes is largely determined by three factors. The first are the specifics of the lamp
Lamp (electrical component)
A lamp is a replaceable component such as an incandescent light bulb, which is designed to produce light from electricity. These components usually have a base of ceramic, metal, glass or plastic, which makes an electrical connection in the socket of a light fixture. This connection may be made...

, reflector and lens
Lens (optics)
A lens is an optical device with perfect or approximate axial symmetry which transmits and refracts light, converging or diverging the beam. A simple lens consists of a single optical element...

 assembly. Different mounting positions for the lamp (axial, base up, base down), different sizes and shapes of reflector and the nature of the lens (or lenses) being used can all affect the pattern of light. Secondly, the specifics of how the lamp is focused affect its pattern. In ellipsoidal reflector spotlights (ERS) or profile spotlights, there are two beams of light emitted from the lamp. When the cones of both intersect at the throw distance (the distance to the stage), the lamp has a sharply defined 'hard' edge. When the two cones do not intersect at that distance, the edge is fuzzy and 'soft'. Depending on which beam (direct or reflected) is outside the other, the pattern may be 'thin and soft' or 'fat and soft.' Lastly, a 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....

 or break up pattern may be applied to ERSs and similar instruments. This is typically a thin sheet of metal with a shape cut into it. It is inserted into the instrument near its aperture. Gobos come in many shapes, but often include leaves, waves, stars and similar patterns.

Focus, position, and hanging

Focus is a term usually used to describe where an instrument is pointed. The final focus should place the "hot spot" of the beam at the actor's head level when standing at the centre of the instrument's assigned "focus area" on the stage. Position refers to the location of an instrument in the theater's fly system
Fly system
A fly system, flying system or theatrical rigging system, is a system of lines , blocks , counterweights and related devices within a theatre that enable a stage crew to quickly, quietly and safely fly components such as curtains, lights, scenery, stage effects and, sometimes, people...

 or on permanent pipes in front-of-house locations. Hanging is the act of placing the instrument in its assigned position.

In addition to these, certain modern instruments are automated
Intelligent lighting
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...

, referring to motorized movement of either the entire fixture body or the movement of a mirror placed in front of its outermost lens. These fixtures and the more traditional follow spots add direction and motion to the relevant characteristics of light. Automated fixtures fall into either the "moving head" or "moving mirror/scanner" category. Scanners have a body which contains the lamp, PCBs, transformer, and effects (color, gobo, iris etc.) devices. A mirror is panned and tilted in the desired position by pan and tilt motors, thereby causing the light beam to move. Moving head fixtures have the effects and lamp assembly inside the head with transformers and other electronics in the base or external ballast. There are advantages and disadvantages to both. Scanners are typically faster and less costly than moving head units but have a narrower range of movement. Moving head fixtures have a much larger range of movement as well as a more natural inertial movement but are typically more expensive.

The above characteristics are not always static, and it is frequently the variation in these characteristics that is used in achieving the goals of lighting.

Stanley McCandless
Stanley McCandless
Stanley McCandless is considered to be the father of modern lighting design. He paved the way for future lighting designers by playing a role in all aspects of theatrical lighting, from the engineering of lighting instruments to consultant work, and of course designing realized theatrical...

 was perhaps the first to define controllable qualities of light used in theater. In A Method for Lighting the Stage, McCandless discusses color, distribution, intensity and movement as the qualities that can be manipulated by a lighting designer to achieve the desired visual, emotional and thematic look on stage. The McCandless Method, outlined in that book, is widely embraced today. The method involves lighting an object on the stage from three angles — 2 lights at 45 degrees to the left and right, and one at 90 degrees (perpendicular to the front of the object).

The lighting designer

Lighting is used to affect the audience's senses and evoke their emotions. The lighting designer is familiar with the various types of lighting instruments and their uses. In consultation with the director and the scenic design
Scenic design
Scenic design is the creation of theatrical, as well as film or television scenery. Scenic designers have traditionally come from a variety of artistic backgrounds, but nowadays, generally speaking, they are trained professionals, often with M.F.A...

er, and after watching sufficient rehearsal
Rehearsal
For other uses, see Rehearsal or Dress rehearsal A rehearsal is a preparatory event in music and theatre that is performed before the official public performance, as a form of practice, and to ensure that all details of the performance are adequately prepared and coordinated for professional...

s, the LD is responsible for providing an Instrument Schedule and a Light Plot. The Schedule is a list of all required materials, including color gel, gobos, color wheels, barndoors and other accessories. The light plot is typically a plan view of the theatre in which the performance will take place, with every luminaire marked. This typically includes approximate focus (the direction it should be pointing), a reference number, any accessories required, and the specifics (or channel number) of its connection to the dimmer
Dimmer
Dimmers are devices used to vary the brightness of a light. By decreasing or increasing the RMS voltage and, hence, the mean power to the lamp, it is possible to vary the intensity of the light output...

 system or lighting control console
Lighting control console
A lighting control console is an electronic device used in theatrical lighting design to control multiple lights at once...

.

A lighting designer must be accustomed to working around the demands of the director or head planner. Practical experience
Experience
Experience as a general concept comprises knowledge of or skill in or observation of some thing or some event gained through involvement in or exposure to that thing or event....

 is required to know the effective use of different lighting instruments and colour in creating a design. Many designers start their careers as lighting technicians in theatres or amateur theatre groups. Often, this is followed by training in one of the many vocational colleges or universities around the world that offer theatre courses. Many jobs in larger venues and productions require a degree from a vocational school
Vocational school
A vocational school , providing vocational education, is a school in which students are taught the skills needed to perform a particular job...

 or college in theatrical lighting, or at least a bachelor’s degree.

Other positions

In theater:
  • Master electrician
    Master electrician
    The Master Electrician in a theatre is responsible for implementing the lighting design for a production drawn up by the Lighting designer. This involves overseeing the preparation, hanging, connection and focusing of stage lighting fixtures.This can be done on a show by show basis, or as a...

    /chief electrician
  • Production electrician
  • Lighting programmer
  • Lighting operator/light board operator
    Light board operator
    The light board operator is the electrician who operates the light board. Depending on the scale and type of production, the board op may be responsible for conventional or automated lighting fixtures, as well as practicals and, in some instances, controlling video as well.Sometimes, most commonly...



In film:
  • Best boy (electrical)
    Best boy
    In a film crew there are two kinds of best boy: best boy electric and best boy grip. They are assistants to their department heads, the gaffer and the key grip, respectively.- Job responsibilities :...

  • Gaffer
    Gaffer (filmmaking)
    A gaffer in the motion picture industry and on a television crew is an electrician that can be head of the electrical department, responsible for the execution of the lighting plan for a production. Gaffer, outside of the motion picture industry, is a traditional British English word for an older...



In music:
  • Rigger
    Rigger (entertainment)
    A rigger is one who works on ropes, booms, lifts, hoists and the like for a stage production .The term "rigger" originally referred to a person who attended to the rigging of a sailing ship. In the age of sail, trading followed seasonal patterns with ships leaving port at set times of the year to...


Lighting instruments


In the context of lighting design, a lighting instrument (also called a luminaire) is a device that produces controlled lighting as part of the effects a lighting designer
Lighting designer
The role of the lighting designer within theatre is to work with the director, choreographer, set designer, costume designer, and sound designer to create an overall 'look' for the show in response to the text, while keeping in mind issues of visibility, safety and cost...

 brings to a show. The term lighting instrument is preferred to light to avoid confusion between light and light sources.

There are a variety of instruments frequently used in the theater. Although they vary in many ways they all have the following four basic components in one form or other:
  • Box/Housing - a metal or plastic container to house the whole instrument and prevent light from spilling in unwanted directions.
  • Light source (lamp).
  • Lens or opening - the gap in the housing where the light is intended to come out.
  • Reflector - behind or around the light source in such a way as to direct more light towards the lens or opening.

Additional features will vary depend on the exact type of fixture.

Most theatrical light bulbs (or lamps, the term usually preferred) are tungsten-halogen (or quartz-halogen), an improvement on the original incandescent design that uses a halogen gas instead of an inert gas to increase lamp life and output. Fluorescent lights are infrequently used other than as worklight
Worklight
In theater, a worklight is a high-intensity light fixture which is used to illuminate the stage for the benefit of technicians. Technicians use these lights rather than the stage lights for a number of reasons. Firstly, it take much less technical knowledge to turn on worklights, so even people...

s because, although they are far more efficient, they are expensive to make dimmed (run at less than full power) without using specialised dimmer ballasts
Electrical ballast
An electrical ballast is a device intended to limit the amount of current in an electric circuit. A familiar and widely used example is the inductive ballast used in fluorescent lamps, to limit the current through the tube, which would otherwise rise to destructive levels due to the tube's...

 and only very expensive models will dim to very low levels. They also do not produce light from a single point or easily concentrated area, and usually have a warm-up period, during which they emit no light or do so intermittently. However fluorescent lights are being used more and more for special effects lighting in theaters. 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 (or HID lamps), however, are now common where a very bright light output is required—for example in large follow spots, hydrargyrum medium-arc iodide
Hydrargyrum medium-arc iodide
Hydrargyrum medium-arc iodide, or HMI, is a Osram brand metal-halide gas discharge medium arc-length lamp manufactured for the film and entertainment industry. Hydrargyrum is Latin for mercury...

 (HMI) floods, and modern automated fixtures. When dimming is required, it is done by mechanical dousers or shutters, as these types of lamps also cannot be electrically dimmed.

Most instruments are suspended or supported by a "U" shaped yoke, or 'trunnion
Trunnion
A trunnion is a cylindrical protrusion used as a mounting and/or pivoting point. In a cannon, the trunnions are two projections cast just forward of the centre of mass of the cannon and fixed to a two-wheeled movable gun carriage...

 arm' fixed to the sides of the instrument, normally near its center of gravity
Center of gravity
In physics, a center of gravity of a material body is a point that may be used for a summary description of gravitational interactions. In a uniform gravitational field, the center of mass serves as the center of gravity...

. On the end of such, a clamp (known as a hook-clamp, C-clamp, or pipe clamp—pipe referring to battens
Batten (theater)
In theater, batten refers to a long metal pole suspended above the stage or the audience from which lighting fixtures, theatrical scenery, tabs or other curtains may be hung...

) is normally fixed, made in a "C" configuration with a screw to lock the instrument onto the pipe or batten from which it is typically hung. One secured, the fixture can be panned and tilted using tension adjustment knobs on the yoke and clamp. An adjustable c-wrench, ratchet (US) or spanner (UK) is often used to assist the technician
Theatrical Technician
A theatrical technician, is a person who operates technical equipment and systems in the Performing arts and Entertainment industry...

 in adjusting the fixture.

Most venues ensure crew and performer safety by attaching a safety cable/chain (a metal wire or chain with a locking carabiner
Carabiner
A carabiner or karabiner is a metal loop with a sprung or screwed gate that is used to quickly and reversibly connect components in safety-critical systems. The word comes from "Karabinerhaken", meaning "hook for a carbine" in German.-Use:...

) to the fixture. In the event that the fixture's clamp(s) were to fail, the cable would arrest the fall of the fixture before it could come in contact with a person. Some larger fixtures can weigh over 100 lb (45.4 kg) and are suspended very high above performers heads. Many venues place strict guidelines regarding the use of safety cables.

All lights are loosely classified as either floodlights (wash lights) or spotlights. The distinction has to do with the degree to which one is able to control the shape and quality of the light produced by the instrument, with spotlights being controllable, sometimes to an extremely precise degree, and floodlights being completely uncontrollable. Instruments that fall somewhere in the middle of the spectrum can be classified as either a spot or a flood, depending on the type of instrument and how it is used. In general, spotlights have lenses while floodlights are lensless, although this is not always the case.

The entire lighting apparatus, including the lights themselves, the physical structure which supports them, and the cabling, control systems, dimmer
Dimmer
Dimmers are devices used to vary the brightness of a light. By decreasing or increasing the RMS voltage and, hence, the mean power to the lamp, it is possible to vary the intensity of the light output...

s, power supplies, and light boards is called the "rig"

Types of lighting fixture

Within the groups of "wash" and "spot" light, there are other, more specific types of fixtures.

Profile
These fixtures feature a compound lens which allows the designer to place obstructions within the image path which are then projected. These obstructions could be "gobos" or shutters. A profile is a spot light, but allows for precise focusing.

Fresnel
A Fresnel is a type of wash light and is named as such due to the Fresnel lens
Fresnel lens
A Fresnel lens is a type of lens originally developed by French physicist Augustin-Jean Fresnel for lighthouses.The design allows the construction of lenses of large aperture and short focal length without the mass and volume of material that would be required by a lens of conventional design...

 it features as the final optical device within the chain.

Traditionally theatre and stage lighting has been of the "generic" type. These are lights which are focussed, geled, and then simply dimmed to give the effect the designer wants. In recent years the emergence of moving lights (or automated lights) has had a substantial impact of theatre and stage lighting.

A typical moving light allows the designer to control the position, colour, shape, and strobing of the light beam created. This can be used for exciting effects for the entertainment or dancefloor use. Moving lights are also often used instead of having a large number of "generic" lights. This is because one moving light can do the work of several generics.

In the UK the nomenclature is slightly different from North America. This article primarily uses the North American terminology. Although there is some adoption of the former naming conventions it has been normal to categorise lanterns by their lens type, so that what in the US is known as a spotlight is known as a Profile
Profile
- Computing and technology :* Profile , a concept in Unified Modeling Language* Apple ProFile, a hard drive* User profile refers to the computer representation of user information...

 or a Fresnel
Fresnel lantern
A Fresnel lantern is a common lantern used in theatre, which employs a Fresnel lens to wash light over an area of the stage. The lens produces a wider, soft-edged beam of light, which is commonly used for back light and top light....

/PC (Pebble/Plano/Prism Convex) in the UK. A Spotlight in the UK often refers to a Followspot
Followspot
A followspot, sometimes known as a spot light, is a powerful stage lighting instrument which projects a bright beam of light onto a performance space. Followspots are controlled by a spotlight operator who follows actors around the stage...

. The following definitions are from a North American point of view. UK naming conventions are used in most of the world, in fact most North American theatres will also use the UK terms except when talking in a more general sense (i.e. get a spotlight to focus on that set piece, or 'flood this area').

In Australia and many other places, the lamps
Incandescent light bulb
The incandescent light bulb, incandescent lamp or incandescent light globe makes light by heating a metal filament wire to a high temperature until it glows. The hot filament is protected from air by a glass bulb that is filled with inert gas or evacuated. In a halogen lamp, a chemical process...

 inside a theatrical fixture are referred to as bubbles. In North American English, a bubble refers to the protrusion that occurs when one's body (or other oily substance) contacts the lamp. Heat will cause the portion of the lamp which has oil on it to expand when it is on creating the bubble, and causing the lamp to explode
Exploding light bulb
An exploding light bulb is a tungsten halogen or high-intensity discharge lamp, which ruptures explosively. Because these lamps operate with high pressure inside a high-temperature envelope, explosion can result in small pieces of hot glass ejected at high speed.- Causes of bulb explosion :If the...

. That is why one should never directly touch the glass portion of a lamp. Cleaning with rubbing alcohol
Rubbing alcohol
Rubbing alcohol, USP / B.P. is a liquid prepared and used primarily for topical application. It is prepared from a special denatured alcohol solution and contains 97.5-100% by volume of pure, concentrated ethanol or isopropyl alcohol...

 will remove the oil.

Lighting controls

Lighting control tools might best be described as anything that changes the quality of the light. Historically this has been done by the use of intensity control. Technological advancements have made intensity control relatively simple - solid state dimmers are controlled by one or more lighting controllers. Controllers are commonly lighting consoles designed for sophisticated control over very large numbers of dimmers or luminaires, but may be simpler devices which play back stored sequences of lighting states with minimal user interfaces. Consoles are also referred to as lighting desks or light-boards.

For larger shows or installations, multiple consoles are often used together and in some cases lighting controllers are combined or coordinated with controllers for sound, automated scenery, pyrotechnics and other effects to provide total automation of the entire show. See show control
Show control
Show control is the use of automation technology to link together and operate multiple entertainment control systems in a coordinated manner. It is distinguished from entertainment control , which coordinates elements within a single entertainment discipline such as lighting, sound, video, rigging...

.

The lighting controller is connected to the dimmers (or directly to automated luminaires) using a control cable or wireless link (e.g. DMX512) or network, allowing the dimmers which are bulky, hot and sometimes noisy, to be positioned away from the stage and audience and allowing automated luminaires to be positioned wherever necessary. In addition to DMX512, newer control connections include RDM
RDM (lighting)
Remote Device Management or RDM is a protocol enhancement to USITT DMX512 that allows bi-directional communication between a lighting or system controller and attached RDM compliant devices over a standard DMX line...

 (remote device management) which adds management and status feedback capabilities to devices which use it while maintaining compatibility with DMX512; and Architecture for Control Networks
Architecture for Control Networks
Architecture for Control Networks is a suite of network protocols for theatrical control being developed by Entertainment Services and Technology Association...

 (ACN) which is a fully featured multiple controller networking protocol. These allow the possibility of feedback of position, state or fault conditions from units, whilst allowing much more detailed control of them.

Dimming

A dimmer is a device used to vary the electrical power delivered to the instrument’s lamp. As power to the lamp decreases, the light fades or dims. It is important to note that some color change also occurs as a lamp is dimmed, allowing for a limited amount of color control through the dimmer. Fades can be either UP or DOWN, that is increasing or decreasing the intensity. Today, most dimmers are solid state, although many mechanical dimmers still exist.

Dimmers are often found in large racks that draw large amounts of three-phase electrical power. The dimmers themselves are often removable modules that range from a 20-ampere, 2.4-kilowatt unit to a 50-ampere or even a 100-ampere unit. They can often be replaced by a constant power module (CPM) which is basically a 20- or 50-ampere breaker in a dimming module casing. Constant power modules are used to supply non-dimming current to other electrical devices (like smoke machines, chain winches, or scenic motors). When a constant power module is installed, the corresponding circuit is energized as long as the dimming pack is on, independent of the lighting console. Failure to use a constant power module on a non-dimming device can result in the damage of the device, specifically when the device relies on an internal transformer that depends on a specific power standard (in the US, 110 V, 60 Hz power). Even if a dimmer channel is trusted to always be operated at full power, during start up and shut down cycles of a lighting control surface, small amounts of noise interference and DMX signal-recycling can cause momentary interruptions in the data stream and cause a dimmer to dim a circuit, so a CPM is necessary to ensure that equipment is not damaged.

Increasingly, with the growth of digital technology, modern lighting instruments are available which allow remote control, not just of intensity, but of direction, color, beam shape, projected image, beam angle and a wealth of other effects. The ability to move an instrument ever more quickly and quietly has become the industry goal. Such automated lights frequently have built-in dimming and so are connected directly to the control cable or network and are independent of external dimmers.

Further reading

  • Pilbrow, Richard (2008) Stage Lighting Design: The Art, the Craft and the Life, Nick Hern Books
    Nick Hern Books
    Nick Hern Books is a London-based independent specialist publisher of plays, theatre books and screenplays. The company was founded by the former Methuen drama editor Nick Hern in 1988.-History:...

    , London. ISBN 978-1854599964.

See also

  • DJ lighting
    DJ lighting
    DJ lighting is a variant of stage lighting that is used by mobile DJs and in nightclubs. DJ lighting is generally used by mobile disco DJs and in most modern nightclubs and many late-night bars....

  • High-key lighting
    High-key lighting
    High-key lighting is a style of lighting for film, television, or photography that aims to reduce the lighting ratio present in the scene. This was originally done partly for technological reasons, since early film and television did not deal well with high contrast ratios, but now is used to...

  • Low-key lighting
    Low-key lighting
    Low-key lighting is a style of lighting for photography, film or television. It is a necessary element in creating a chiaroscuro effect. Traditional photographic lighting, three-point lighting uses a key light, a fill light, and a back light for illumination...

  • Tree lights
  • Gas Lighting
    Gas lighting
    Gas lighting is production of artificial light from combustion of a gaseous fuel, including hydrogen, methane, carbon monoxide, propane, butane, acetylene, ethylene, or natural gas. Before electricity became sufficiently widespread and economical to allow for general public use, gas was the most...


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