||This article needs additional citations for verification. (August 2009)|
Stage lighting is the craft of lighting as it applies to the production of theatre, dance, opera and other performance arts. Several different types of stage lighting instruments are used in this discipline. In addition to basic lighting, modern stage lighting can also include special effects, such as lasers and fog machines. People who work on stage lighting are commonly referred to as lighting technicians.
Functions of lighting 
Stage lighting has multiple functions, including:
- Selective Visibility: 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 from 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 ("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 takes 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, direction and focus.
Intensity is measured in lux, lumens and foot-candles. The intensity of a luminaire (lighting instrument or fixture) depends on a number of factors including its lamp power, the design of the instrument (and its efficiency), optical obstructions such as color gels or mechanical filters, the distance to the area to be lit and the beam or field angle of the fixture, the color and material to be lit, and the relative contrasts to other regions of illumination.
Color temperature is measured in kelvins. A light's apparent color is determined by its lamp color, the color of any gels in the optical path, its power level, and the color of the material it lights.
A tungsten lamp's color is typically controlled by inserting one or more gels into its optical path. In the simplest case, a single gel is inserted into the optical path to produce light of the same color. For example, a blue gel is used to create blue light. Custom colors are obtained by means of subtractive CMY color mixing, by inserting combinations of cyan, magenta and yellow dichroic filters into the optical path of the lighting fixture. The inserted filters may have varying densities, with correspondingly varied percentages of transmission, that subtractively mix colors. This creates custom colors in a manner similar to ink jet printers, which mix varied densities of cyan, magenta and yellow inks. Manufacturers will sometimes include an additional green or amber ("CTO" color correction) filter to extend the range (gamut) of subtractive color mixing systems,
Lamp power also influences color in tungsten lamps. As the lamp power is decreased, the tungsten filament in a bulb will tend to produce increasing percentages of orange light, as compared to the nearly white light emitted at full power. This is known as amber drift or amber shift. Thus a 1000-watt instrument at 50 percent power will emit a higher percentage of orange light than a 500-watt instrument operating at full power.
LED fixtures create color through additive color mixing with red, green, blue, and in some cases amber, LEDs at different intensities. This type of color mixing is often used with borderlights and cyclorama lights.
|A gobo of this shape in a fixture with a red gel would produce a pattern like the one shown to the right.|
Direction 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, reflector and lens 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 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, or templates, 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 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, 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 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).
An alternative formulation is by Jody Briggs, who calls them Variable of Light: Angle, Color, Intensity, Distance, Texture, Edge-quality, Size, and Shape. 
Lighting professionals 
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 designer, and after watching sufficient rehearsals, 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 system or lighting control console.
A lighting designer must be accustomed to working around the demands of the director or head planner. Practical experience is required to know the effective use of different lighting instruments and color 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 or college in theatrical lighting, or at least a bachelor’s degree.
Other positions 
- Master electrician/chief electrician
- Production electrician
- Lighting programmer
- Lighting operator/light board operator
Lighting equipment 
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 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 worklights because, although they are far more efficient, they are expensive to make dimmed (run at less than full power) without using specialised dimmer ballasts 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 lamps (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 (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 arm' fixed to the sides of the instrument, normally near its center of gravity. On the end of such, a clamp (known as a hook-clamp, C-clamp, or pipe clamp—pipe referring to battens) 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 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) 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 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 includes the lights themselves, the physical structure which supports them, the cabling, control systems, dimmers, power supplies, and the light boards. (lighting console)
Hanging the lights or hanging the battons to hang the lights is known as 'rigging'.
Types of lighting fixture 
Within the groups of "wash" and "spot" light, there are other, more specific types of fixtures.
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.
A Fresnel is a type of wash light and is named as such due to the Fresnel lens 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, color, 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 or a Fresnel/PC (Pebble/Plano/Prism Convex) in the UK. A Spotlight in the UK often refers to a Followspot. 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 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. That is why one should never directly touch the glass portion of a lamp. Cleaning with rubbing 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.
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 (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 (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.
A dimmer is a device used to vary the average voltage applied to an instrument's lamp. The brightness of a lamp is proportional to its electric current, which in turn is proportional to the applied lamp voltage. When the applied voltage is decreased, a lamp's electric current will also decrease, thus reducing the light output from the lamp (dimming it). Conversely, a higher voltage will cause higher lamp current and increased (brighter) light output. Dimmers are frequently found in large racks that draw significant three-phase electrical power. They are often removable modules that range from 20-ampere, 2.4-kilowatt to 100-ampere units.
In the case of incandescent lamps, some color changes occur as a lamp is dimmed, allowing for a limited amount of color control through a dimmer. Fades (brightness transitions) can be either UP or DOWN, meaning that the light output is increasing or decreasing during the transition. Most modern dimmers are solid state, though many mechanical dimmers are still in operation.
In many cases, a dimmer can be replaced by a constant power module (CPM), which is typically a 20- or 50-ampere breaker in a dimming module casing. CPMs are used to supply line voltage to non-dimming electrical devices such as smoke machines, chain winches, and scenic motors that require constant operating voltage. When a device is powered by a CPM, it is fully energized whenever the CPM is turned on, independent of lighting console levels. CPMs must be used (in lieu of dimmers) to power non-dimming devices that require specific line voltages (e.g., in the US, 110 V, 60 Hz power) in order to avoid damage to such devices. Dimmers are seldom used to control non-dimming devices because even if a dimmer channel is trusted to always operate at full power, it may not be controlled when communications are disrupted by start up and shut down of the lighting control surface, noise interference, or DMX disconnects or failure. Such a loss of control might cause a dimmer to dim a circuit and thus potentially damage its non-dimming device.
Increasingly, modern lighting instruments are available which allow remote control of effects other than light intensity, including direction, color, beam shape, projected image, and beam angle. The ability to move an instrument ever more quickly and quietly is an industry goal. Some automated lights 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, London. ISBN 978-1-85459-996-4.
See also 
- , Stage Lighting Design Principle and Process
-  theatrecrafts' Types of Lanterns.
- McCandless, Stanley (1958). A Method of Lighting the Stage, Fourth Edition. New York: Theatre Arts Books. pp. 9–10. ISBN 978-0-87830-082-2.
- Gillette, J. Michael (2003). Designing With Light: An Introduction to Stage Lighting, Fourth Edition. McGraw Hill. pp. 9–10. ISBN 0-7674-2733-5.
- Gillette, J. Michael (2003). Designing With Light: An Introduction to Stage Lighting, Fourth Edition. McGraw Hill. p. 10. ISBN 0-7674-2733-5.
- Gillette, J. Michael (2003). Designing With Light: An Introduction to Stage Lighting, Fourth Edition. McGraw Hill. p. 7. ISBN 0-7674-2733-5.
- Gillette, J. Michael (2003). Designing With Light: An Introduction to Stage Lighting, Fourth Edition. McGraw Hill. p. 50. ISBN 0-7674-2733-5.
- Gillette, J. Michael (2003). Designing With Light: An Introduction to Stage Lighting, Fourth Edition. McGraw Hill. pp. 62–64. ISBN 0-7674-2733-5.
- Gillette, J. Michael (2003). Designing With Light: An Introduction to Stage Lighting, Fourth Edition. McGraw Hill. p. 181. ISBN 0-7674-2733-5.
- Gillette, J. Michael (2003). Designing With Light: An Introduction to Stage Lighting, Fourth Edition. McGraw Hill. pp. 152–158. ISBN 0-7674-2733-5.
- Lampert-Gréaux, Ellen (2007-05-01). "Remember Stanley McCandless?". Live Design Online (Penton Media, Inc). Retrieved 2008-01-29.
- McCandless, Stanley (1958). A Method of Lighting the Stage, Fourth Edition. New York: Theatre Arts Books. pp. 55–56. ISBN 978-0-87830-082-2.
- Briggs, Jody (2003). Encyclopedia of Stage Lighting. Jefferson, NC: McFarland. pp. 318–319. ISBN 0-7864-1512-6.
- Gillette, J. Michael (2003). Designing With Light: An Introduction to Stage Lighting, Fourth Edition. McGraw Hill. pp. 12–13. ISBN 0-7674-2733-5.
-  Scenic Art for the Theatre by Susan Crabtree and Peter Beudert.
-  Interior Graphic Standards by Corky Binggeli and Patricia Greichen p. 558
-  Stage Lighting Primer
- Connecticut College Theater Services Hazard Communication Guide, Please see 'Lights' section.
- Gillette, J. Michael (2003). Designing With Light: An Introduction to Stage Lighting, Fourth Edition. McGraw Hill. pp. 95, 97, 100–102. ISBN 0-7674-2733-5.
- Gillette, J. Michael (2003). Designing With Light: An Introduction to Stage Lighting, Fourth Edition. McGraw Hill. p. 96. ISBN 0-7674-2733-5.
- Gillette, J. Michael (2003). Designing With Light: An Introduction to Stage Lighting, Fourth Edition. McGraw Hill. p. 89. ISBN 0-7674-2733-5.
- Gillette, J. Michael (2003). Designing With Light: An Introduction to Stage Lighting, Fourth Edition. McGraw Hill. p. 92. ISBN 0-7674-2733-5.
|Wikimedia Commons has media related to: Stage lighting|
- FAQ from the Stagecraft mailing list
- Stage Lighting for Students
- How to Work with a Lighting Designer
- Stagelink Directory of Lighting Designers
- UK Sound and Lighting Community