|
Lighting Glossary
A
ACL (Aircraft Landing Light)
A 28 volt very narrow beam PAR lamp (used on aircraft) often adapted for use
in PAR64 and PAR46 fixtures. ACLs are commonly wired with 4 lamps in series
to bring the required voltage of the circuit close to 120 volts. ACL lamps
are typically brighter, more intense, and have a higher color temperature
than standard PAR lamps. They typically are more expensive and have a shorter
lamp life.
Aircraft Cable
A stainless steel stranded cable commonly used for theatrical rigging.
Amperage
A measure of the amount of current flowing in an electric circuit. Devices
such as cables and dimmers are rated in terms of their maximum capacity in
amps. Devices such as lamps or motors that consume electrical energy rated
in terms of amperage required for proper operation. Any technician working
with electrical equipment must understand how to properly connect equipment
to not create an overload situation. Amperage=Wattage/Voltage.
Power is typically ordered in amounts of amps since volts do not tend to vary
much. Typically power is a house or master account charge and can vary greatly
from one venue to the next.
AMX (Analog Multiplex)
A classification of control protocols which sends analog dimmer control signals
serially down two wires. A common AMX protocal is AMX 192 which allows up to
192 dimmers to be controlled via a two wire control cable.
Automated Fixture (aka Intelligent Lighting, Moving Instruments, or just "Movers")
A lighting fixture in which some functions have been electronically or mechanically
automated. Common automated functions include: color change, beam movement,
shutter, iris, and gobo change, as well as internal dimming capabilities. Completely
automated fixtures may also include many other effects and functions. Automated
fixtures break into two main categories: moving mirror, and moving yoke (or
"head"). Combined with sophisticated computer control, data distribution systems,
and
trained
operator/programmers, these lighting systems provide enormous flexibility in
creating dynamic lighting images.
Unlike PAR's and ACL's there are very wide varieties and manufacturers of these
fixtures. WARNING: Besides per unit costs that are much more than static lights,
these instruments also require more programming time by the lighting engineer
and often a spelialized programmer is needed.
Automated Fixture Control Console
A lighting control console designed specifically for the purpose of controlling
and storing/playing back cues for automated fixtures. These consoles often
have subsystems for controlling different features of automated fixtures such
as color change, gobo, and focus position. Complex cue structures, effects,
and chases are typical features of automated fixture control consoles. Three
primary types of automated fixture consoles include: proprietary consoles designed
to work primarily with one type of automated fixture, generic controllers which
are programmed to control many different types of automated fixtures, and hybrid
controllers which combine the functions of standard theatrical memory consoles
with those of an automated fixture console.
AutoPilot (TM)
A proprietary product developed by Wybron in the early 1990's to interface
a 3-dimensional locating system with pan and tilt functions of automated fixtures.
A sensor attached to an actor or musician is used by the system to locate the
actor on stage. Resulting data is can be fed to automated fixture controller
to allow lights to follow actors in real time as they move around the stage.
The resulting effect can be similar to that of a followspot.
B
Back Light
A lighting design term referring to any light which comes primarily from behind
the actor, musician, or object being lit. Backlighting is associated with
strong highlights or halo effects.
Ballyhoo
A followspot move in which the operators continuously move the beam in a figure-eight
motion around the stage or audience. This term is also used to describe similar
movements performed by moving lights.
Bare-ends
An electrical term referring to the ends of a feeder cable set which do not
have any permanent connector attatched to them. Bare ends are often used to
tie dimmer feeder cable into a house power supply or company switch.
See Also: Connector Feeder Cable
Blackout (B.O., B/O)
A lighting design term referring to a light cue which takes the stage quickly
into darkness. A blackout is often abbreviated B/O.
Box Truss
An aluminum or steel support structure often used for temporary rigging of
lights, scenery, or sound equipment. As the name suggests a box truss is rectangular
in shape creating a rigid structure which is easy to stack and load onto a
truck. An additional advantage of box truss over other truss shapes is the
ability to hang lighting instruments inside the truss, where they can remain
protected while in transport.
Break-out
A cable connecting device which breaks a multi-circuit cable (multi- cable)
into individual circuits.
Bridle
A rigging device or method which distributes a single point of a load to more
than one hanging point.
Bump Button
A momentary switch or button on a lighting control console which brings a channel
to a level of full when pressed. Bump buttons allow rapid manual control over
lighting control channels. On some consoles bump buttons can be put into solo
mode where all channels except those controlled by the bump button go out.
Bump Cue
A lighting cue which happens instantly (Time=0). Bump cues are traditionally
used to emphasize similar abrupt changes in music, choreography, or to mark
the end of a scene. A bump cue where all lights go out is called a blackout.
C
Cable
Common term describing any number of types of electrical connecting devices.
All cables employ some type of conductor, usually stranded copper wire, and
some type of insulation to protect it. Common cable types related to stage
lighting include: stage cable, multi-cable, feeder cable, and control cable.
Camlock (TM)
A locking single contact connector commonly used to connect feeder cables and
portable dimmer racks.
The Ground and Neutral connectors are often reversed so that accidental connections
of power to either the Neutral or Ground cables can be avoided.
Chain Hoist
A lifting device comprised of an electric motor and gear/chain drive system.
Chain hoists are commonly used to lift portable trusses into place for touring
concerts and shows.
Hoists are rated by their load capacity and are commonly 1/4 ton, 1/2 ton and
1-ton.
Chase
A lighting design term referring to a group of lights which are turned on and
off in a sequence. A chase can be as simple as a single string of lights flashed
sequentially around a sign by a mechanical or electronic switching device (chaser
or chase unit), or by utilizing the chase (or effect) functions of a computer
memory console, a chase can be a complex multi-part cues affecting large groups
of lighting instruments.
Circuit
An electrical circuit. In theatrical lighting terms a circuit usually refers
to the part of a lighting circuit which extends from the dimmer to the lighting
instrument. In permanent installations where this is a fixed relationship (dimmer-per-circuit)
the terms dimmer and circuit are often used interchangeably.
Color Boomerang
A levered frame device within a followspot in which allows different color
filters to be introduced into the beam. Standard followspot boomerangs have
space for 6 or 7 different colors to be inserted. During a show individual
or combined frames can be quickly added or dropped from the beam as needed.
Color Filter
Color media placed in front of or within a lighting fixture to
alter the color of the light produced. Filters for conventional
fixtures are often made of
a dyed polyester film. Since dyed filters work by absorbing unwanted colors
and passing desired colors, they deteriorate from heat and must be replaced
when they "burn up". Automated fixtures use more permanent dichroic
color filters which are created by vacuum depositing thin films onto heat resistant
glass.
See Also: Dichroic Color Filter
Color Scroller
A mechanical device usually used as an accessory to a conventional lighting
fixture to remotely change the color of the light produced by the unit. A color
scroll, or gel string, consists of individual color filters taped end to end
to form a long string. Gel strings typically contain between 10 and 32 different
colors. The color scroller utilizes a remote controlled stepping motor, and
sensors to be able to correctly position the scroll so that any individual
color is in the beam of light. Scrolls can also usually be moved continuously
from one end to the other at varying speeds.
Color Temperature
The measurement of a the color quality of a lamp measured in degrees Kelvin.
A standard 1000 watt tungsten halogen theatrical lamp has a color temperature
of around 3200. Kelvin.
Company Switch
A disconnect or electrical connecting/switching device in a theatre or venue
which is traditionally used by a touring company to connect all of its touring
electrical equipment. Portable lighting dimming systems are usually "tied-into" the
company switch.
Computer Memory Console
A lighting console in which cues can be stored and executed electronically.
Computer consoles also employ many show editing and cue building functions
which make the cue writing or programming process easier. Computer consoles
can be divided into three basic types: cue-only type consoles, theatrical "classic" tracking
consoles, and automated fixture control consoles.
Connector
A plug. A device that allows the fast, safe, and convenient connection and
disconnection of electrical equipment. There are many types of connectors used
for entertainment lighting purposes. Some common types include Camlock for
feeder cable and dimming racks, pin connector for stage cable, and XLR connector
for control cable.
Control Cable
A term describing any cable which carries control signals or protocals between
electrical or electronic devices. This signal can be as simple as a low voltage
analog signal or as complex as a bi-directional digital protocol. Increasingly,
performance electronics are utilizing computer ether-net protocols over thin-net,
or fiber-optic network cables.
Control Channel
A lighting control concept analogous to a control slider or fader. On manual
or preset controllers this may refer to an actual fader or slider. On a computer
memory console a channel may only be represented by a number which is assigned
by the system to control any number of physical dimmers, color scrollers, or
other devices. Generally a control channel represents the smallest easily divisible
set of controls a designer has over groups of lighting instruments. A soft
patch or pin patch is used to assign dimmers or groups of dimmers to individual
control channels.
Controller
A lighting control console or light board. Common types include the preset
board, the computer memory console, as well as specialized automated fixture
controllers such as the Vari-Lite Artisan II console.
Conventional Lighting Fixture
A standard lighting fixture such as a PAR can, Fresnel, or ERS, which offers
no built in automated functions.
Cracked Oil Fog Machine
A simple type of fog machine which atomizes oil into a fine atmosphere, usually
by introducing compressed air into a reservoir containing mineral oil. Crackers
are also available which crack water into a very fine mist. Haze machines produce
effects similar to oil crackers without leaving an oily residue on surfaces.
See Also: Haze Machine Fog Machine
Cross Fade (X-Fade, XFAD)
A lighting design term referring to a cue in which one set of lights increases
in intensity while another set simultaneously decreases in intensity. A crossfade
is one common way in which a change of scene can be indicated in a theatrical
production. On a manual controller the master handles literally must be cross
faded from one scene bank to another to accomplish a cross fade.
Cue (Q)
A point in a live show when a signal is given for some action to take place.
See Also: Light Cue
Cut 1
A cut of color. A color filter cut for use in the color frame of a specific
lighting instrument.
See Also: Lighting Instrument Color Filter
Cut 2
Describes an element of the show which has been removed or deleted. Often lines,
scenic items, and light cues are "cut" from a production during the
rehearsal process.
Cyberlight (TM)
Originally introduced in 1993 the Cyberlight is a moving mirror type automated
fixture manufactured by Lightwave Research/High End Systems.
Cyclorama (Cyc)
A theatrical scenic term describing a smooth backdrop which is often used to
create a sky background for a production.
D
Dichroic Color Filter
Color filters manufactured by vacuum depositing thin films onto heat resistant
glass. Dichroic filters reflect rather than absorb unwanted wavelengths and
so remain cooler and less subject to burn out. The process for creating dichroic
filters is very precise and much more saturate (purer) colors can be created.
As a result these filters are quite expensive and are used primarily in automated
fixtures.
Dimmer
A device which causes connected lamps to decrease in intensity. Most dimmers
for entertainment lighting use are some variation of an SCR. Individual dimmers
are traditionally arranged in modules of two dimmers with modules combined
into dimmer racks.
Dimmer Pack
A portable enclosure containing between 3 and 12 dimmer modules.
Dimmer Per Circuit
A dimming and circuiting system in which every circuit in the system has its
own permanently wired dimmer.
Dimmer Rack
Dimmer racks contain individual dimmer modules arranged for convenient electrical
connection. Some racks are designed for permanent installation, while touring
racks are designed for portable use. Dimmer racks typically contain 6, 12,
24, or 48 dimmer modules typically with 2 dimmers per module.
DMX (Digital multi-plex)
DMX 512 is a standard dimmer control protocol implemented by U.S.I.T.T. to
provide a means for interfacing dimming and control equipment from different
manufacturers. A single DMX control cable carries dimmer intensity information
for 512 dimmers serially down 2 wires. Many other devices can be controlled
via DMX. Examples include fog machines, strobe lights, and automated fixtures.
These devices, developed since DMX was first implemented, may interpret the
DMX intensity data in different ways. An automated fixture, for example, may
interpret a level of 50 on dimmer 1 as meaning move mirror in the x direction
to the mid-way point.
Dry-ice Fogger
A simple fog machine which creates thick, opaque, low-lying or ground fog by
the emersion of frozen CO2 in hot water. This type of fogger is often made
from a large drum containing a heating element and some type of basket in which
dry-ice can be lowered into the water. The resulting fog is often forced through
a hose to the desired location onstage. Dry-ice fog effects are somewhat short
lived as the dry-ice quickly evaporates and the water cools. Dry-ice is often
used to cool the fog produced by other types of fog machines making it to stay
close to the ground. These chiller modules or attachments are little more than
insulated coolers attached to the output end of a standard fog machine.
E
Ellipsoidal Reflector Spotlight (ERS)
The most common theatrical lighting fixture employing an ellipsoidal reflector,
a sharp focusing lens system, and framing or shuttering devices. Commonly
called a Leko or, in the UK a profile spot, the ERS has the ability to project
patterns (gobos) and make very precise shutter cuts.
See Also: Shutter Cut Gobo Leko (TM) Shutter
F
--------------------------------------------------------------------------------
Fade To Black (FTB)
A lighting design abbreviation for fade to black. It indicates that a light
cue takes all channels to zero over a period of time.
Feeder Cable
The cable which feeds or supplies power to a dimmer rack. Feeder cable is usually
heavy gauge cable capable of safely carrying the hundreds of amps necessary
to supply as many as 96 individual dimmers in a rack. Feeder cables are usually
connected via Camlock connectors. A bare-end or tail often connects one end
of a feeder to the power supply or company switch.
Fill Light
A lighting design term which describes a light source or direction which is
secondary, or fills in after a primary or key light source has been established.
Fluorescence
A process by which certain pigments or materials can be made to appear to self
illuminate when exposed to UV light.
Fluorescent Lamp
A type of lamp which converts UV light into visible light through fluorescence.
Fluorescent lamps are one of the least commonly used lamps on stage.
Fly-away
A lighting design term referring to a cue in which automated lights move upward
away from the stage in a sweeping motion.
Focus
The process by which a lighting instrument is either manually or remotely positioned
to light a specific part of the stage. With conventional fixtures focus is
performed after lighting equipment is hung in place and is connected to the
proper circuit. Automated fixtures can be remotely focused and may have many
different focuses for a particular show. Focus presets are often created as
libraries of focus points for a show. Focus presets as well as conventionally
focused equipment must be checked any time a show changes venues, as the relationship
of lighting instrument and stage may change.
Focus Preset
A feature of some automated fixture consoles which allows libraries of memorized
focus positions to be stored centrally in memory. Presets can then be accessed
individually by cues to position fixtures at pre- determined locations on stage.
Using focus presets is a much more efficient method for cueing automated fixtures
than writing positions individually into every cue in a show.
Fog
A term used to describe a range of stage fog, haze, and smoke effects. Fog
is commonly created from the heat expansion and atomization of a fog fluid
in a fog machine.
Fog Machine (Fogger)
A device which creates fog by vaporizing a fluid into a fine atmosphere through
a heat exchange system. Some fog machines use oil- based fluids while other
fluids are water or glycol based. The type of machine and fluid used affects
the quality of the atmosphere produced. Fog can be very light and rise quickly
in the slightly heated air, or can be very heavy and dense and tend to hang
in large clouds. Fog machines can create effects similar to haze machines,
dry-ice or liquid nitrogen foggers, oil crackers, etc, but are best at producing
large volumes of dense atmosphere quickly.
Followspot
A manually operated lighting fixture specially designed for following performers
as they move about the stage. Most followspots employ some method for manual
control of iris, shutter, dowser, as well as a color boomerang.
Fresnel
A standard stage lighting instrument. The Fresnel produces a characteristically
soft edged beam created by the pebbled surface on the back of the Fresnel lens.
Since the Fresnel is used extensively in film and television production there
are a vast range of types available. Fresnels can range in size from 3/" in
diameter to several feet and in wattage from 150 watts to 10 kilowatts or more.
G
Ganging
The process of combining 2 or more lamps into one circuit using a twofer or
similar connecting device. Also used to refer to any situation where two
or more components of and electrical system are combined together in a parallel
ciurcuit.
Gate
A place within the optical train of an ERS where shutters, gobos, or other
items can be sharply focused by the unit.
Gel
A term used loosely to describe expendable color filters used in stage lighting.
Originally made of thin sheets of dyed gelatin, color filters are now made
from polymer plastics.
Gel String
A series of color filters connected end to end used in a color scroller.
Gobo
Also called a pattern, template, or cookie, a gobo is commonly an etched steel
cut-out placed at the gate of an ERS which produces a pattern of light and
shadow in the beam of light. Patterns are commercially available from theatrical
lighting dealers or can be made by hand using a number of different processes.
Many automated fixtures employ a variety of gobos and gobo effects. These include
rotatable gobos, gobo combinations, glass colored gobos, or even sophisticated
imaging systems which combine dichroic color effects with patterns or custom
designs or artwork.
H
Hanging Point
The point where rigging is attached to a truss or piece of scenery. Location
of hanging points must be determined for structural safety, but must be reconciled
with available pickup points in the building or structure to which the truss
is being rigged.
Haze Machine (Hazer)
A device, similar to a fog machine, which produces a light, fine atmosphere
by atomizing a special haze fluid. Since a haze machine does not utilize a
heat exchange system, like a fogger, there is no warm up time. The atmosphere
produced by a haze machine is dense enough to reveal beams of light in the
air, but not so dense as to become opaque.
HID (High Intensity Discharge)
A type of lamp such as a mercury or sodium vapor lamp that produces light by
causing an inert gas to discharge photons. HID lamps find special uses in entertainment
lighting and make good UV sources. HID lamps require special ballasts and are
generally not dimmable.
HMI (Halide Metal Inert gas)
A double ended short arc lamp which creates light by causing an electrical
current to jump between two electrodes within an inert gas atmosphere. HMI
lamps produce many lumens per watt making them many times more efficient than
incandescent sources. HMI lamps typically burn at around 5600. Kelvin.
I
I.A.T.S.E. (International Alliance of Theatrical and Stage Employees)
A union representing professional craftspeople in the entertainment industry.
This union includes stage electricians, carpenters, and projectionists. A
venue is a union house if its local crew belongs to IATSE.
Incandescent Lamp
A lamp which creates light by heating up a thin filament, usually tungsten
wire. Most standard household light bulbs as will as tungsten halogen lamps
are incandescent. The color temperature of most incandescent lamps ranges from
1800. Kelvin to about 3800. Kelvin.
Intellabeam (TM)
A moving mirror type automated fixture introduced by High End Systems/Lightwave
Research in the late 1980's.
Iris
A device commonly used in an ERS or followspot to reduce the apparent diameter
of the beam of light. Many automated fixtures also employ a motor controlled
iris which can be used to remotely adjust the beam diameter.
J
Jumper
A stage cable. Often used to refer to a short length of stage cable.
See Also: Stage Cable
K
Key Light
A lighting design term that describes a strong primary light source. Other
secondary lights are often described as being fill lights. The term High
Key lighting describes even bright lighting such as might be produced on
television news set.
Kill
To turn a channel, lighting unit, or another electric device off. Synonymous
with "save", and "at zero", or "out".
Kilowatt
1000 watts.
L
Lamp
A device which converts electrical energy into light. Common lamps used in
entertainment lighting include incandescent, HID, HMI/HTI, and fluorescent.
Laser
A device which produces pencil thin beams of coherent monochromatic light.
Used primarily for special effects, lasers combined with beam splitters, scanners,
and mirrors can be used to create a variety of three-dimensional images in
fog or similar atmosphere. A laser and scanning system connected to a computer
controller can be used to project complex animation effects.
Laser Bed
A complete laser assembly including laser tube, control system, scanning or
beam splitting components or other effects.
Laser Head
The laser tube assembly part of a laser system.
Leko (TM)
A trademark for a brand of ERS currently owned and marketed by Strand Lighting.
Light Board
A lighting control console or desk.
Light Board Operator (Board Op)
The person who runs the lighting control console, programming and executing
cues as directed by the lighting designer.
Light Cue (LQ, LX Q, Q)
A lighting design term referring to a point in a show at which a predetermined
change in the lighting is executed. The lighting director or stage manager "calls
the cue" usually by saying "go," and the light board operator
executes the lighting change. A change may occur instantly, as in a bump cue,
or take place as a long fade over time. On simple controllers a cue can be
thought of as a combination of channels at specific levels which create the
lighting for a specific moment in a show. More sophisticated controllers build
cues in increasingly complex ways making the idea of a cue a more abstract
concept. Cue is often used to describe a moment or picture (also called a look
or state) created by lighting on stage.
Light Show
A term describing a production where the lighting is or takes a primary focus.
The idea of a light show may have developed from the psychedelic light show
of the late 60's, but is now used to describe a range of laser and lighting
spectacles.
Lighting Control Console
The head end of a lighting system. The lighting control console sends information
via control cables to dimmers or other devices instructing what they should
do. Run by a light board operator, or as is common on a touring production
by the lighting designer or lighting director, the lighting control console
stores and executes all of the light cues for a performance. Common types of
lighting consoles include the preset board and computer memory console.
Lighting Designer
The person whose primary responsibility is the visual design of the lighting
for a project or production. In theatrical terms the Lighting Designer is responsible
for all aspects of the aesthetic design of the show.
Lighting Director
Commonly used in the television and touring show industry to describe the person
in charge of the lighting. Often the lighting director is the lighting designer
for the production. In other cases the lighting director for a touring show
is working from an original production design by the lighting designer.
Lighting Instrument
Often called a luminair, lighting unit, or lighting fixture, a lighting instrument
is a device that is minimally comprised of a lamp, lamp housing, and some type
of clamp to attach it to a mounting structure.
Liquid Nitrogen Fogger
A fogging system which uses liquid nitrogen to cool water? and produce heavy
clouds of dense ground fog. The nitrogen fogger has the chief advantage over
dry-ice fog, that the reaction can be continued indefinitely.
Load-in (aka Installation)
The process by which all of the physical elements of a show are unloaded
from a truck and installed at a venue for a performance. Load-in is usually
accomplished by a combination of technicians from the production company crew
and the local crew.
Load-out (aka Dismantle and Strike)
The process by which all of the elements of a production are struck from the
theatre and loaded onto a truck for touring.
Local Crew
The technicians who work at a particular venue, but do not tour with a production.
A local crew may be hired in by the venue just for a particular production
or may be permanent staff. Local is also used to describe a local branch of
a union such as I.A.T.S.E. which provides crews to theatrical venues.
Look
A lighting design term used to refer to a specific stage image created by lighting.
Also called a "state" by designers in the UK. A show may be described
as having a certain look, or a particular scene or song may have a look or
series of looks which are returned to or repeated.
Lumen
A unit used to measure the brightness of a light source. The more lumens produced
per watt of power supplied, the more efficient a light source is. ANSI Lumens
are a unit of measurement established by the American National Standards Institute
used to rate the brightness of video projectors.
Luminair
A lighting instrument. A common term in the UK, luminair is finding more common
usage in the United States.
Luminance
The measured amount of light reflected by a surface.
M
Master Electrician
In entertainment lighting, the Master Electrician's primary responsibility
is the technical execution of the lighting design as specified by the lighting
designer or lighting director. Typical tasks include the organization of
crews and schedules as well as the technical planning, rental, installation,
and maintenance of equipment. A Master Electrician is rarely licensed as
a professional general electrician.
MIDI (Musical Instrument Digital Interface)
A serial control protocol designed to allow musical devices such as keyboards
and synthesizers to share musical information. Many lighting manufacturers
have provided a means by which lighting devices can respond to specific MIDI
signals. MIDI-show-control, an extension to MIDI, defines a standard way in
which simple cue execution commands specific to show controllers can exchange
information through MIDI systems.
Mirror Ball
Self explanitory.
Moving Mirror Automated Fixture
A classification of automated fixtures which achieves beam motion by reflecting
the beam off of a remotely controlled motorized mirror. The Cyberlight (TM)
by High End Systems, and the Roboscan (TM) by Martin, are examples of moving
mirror automated fixtures.
Moving Yoke (Head) Automated Fixture
A classification of automated fixtures which achieves beam motion by remote
motor controlled movement of the yoke and body of the fixture. The Vari-Lite
series of automated fixtures (TM) Vari-Lite, are an example of moving yoke
automated fixtures.
Multicable (Mult, Multi)
A cable designed to supply power from dimmers to multiple separate lighting
instruments down a single multi-conductor cable. Standard multi-cables can
carry the equivalent of 6 or 12 standard stage cables corresponding to the
same number of circuits. A break-out is used at either end to break the multi
cable apart into individual circuits. Multicables have the advantage of being
much smaller than bundles of multiple stage cables.
See Also: Circuit Stage Cable Lighting Instrument Dimmer Cable
O
PAR Can
A conventional lighting fixture which represents the original workhorse of
the rock and roll touring industry. A PAR can is comprised of a PAR (Parabolic
Aluminized Refelctor) lamp and a mounting fixture and base (the can). Standard
PARs range in size from 4.75" (PAR 38) to 8" (PAR 64). The most
common configuration for event use is the PAR64. The PAR64 is usually fitted
with a 1000 watt narrow or very-narrow beam PAR lamp. ACLs are often substituted
for PAR lamps. The Source 4 PAR has a removeable lense and sparate lamp.
Patch
The process by which different parts of an electrical or control system are
selectively connected. Patching traditionally takes place at several key points
in a lighting system: at a patch panel, at a pin patch, or in a soft patch.
Patch Panel
An electrical panel where individual circuits can be connected to the physical
dimmers in a dimming system. Common patch panels look like large old-fashioned
telephone switchboards. Patch panels have all but been replaced by dimmer per
circuit systems in which the dimmer to circuit relationship is permanently
fixed. A touring lighting system rarely includes a patch panel since individual
connections between circuits can be made directly on the dimmer rack.
Pickup Point (Pick Point)
An architectural or structural point to which scenery or trussing can be rigged
for flying purposes. Available pickup points in a particular venue must be
reconciled with necessary hanging points on the equipment to be lifted. Pick
points must never be used unless the venue can certify them as having a load
limit specified in pounds.
Pigtail
In a permanent circuiting system, a short cable extending from a circuit box
which has a female connector into which a lighting instrument is plugged.
Pin Connector
A standard connector for stage cable which is also called a 2P&G connector
for 2 pins and ground. Pin connectors are generally rated for 20 amps at 120
volts and are the most common type of connector for the touring industry.
Pin Patch
As part of a lighting control console, the pin patch is a matrix of pins which
allows individual dimmer control signals to be grouped together into channels
on a manual or preset board. The pin patch pre- dates the soft patch found
on most computer memory lighting control consoles.
Pre-Rig Truss (PRT)
A truss or truss section which has been pre-assembled with lighting equipment
and connecting devices in the shop prior to installation at load-in. Using
a PRT saves many hours when loading a show in or out, and makes
for an efficient method of storing equipment on a truck.
Preset Board
A lighting ontrol console comprised of banks or "scenes" of redundant
sliders each controlling one channel of the lighting system. Individual looks
can be set up on banks and by using scene masters one look can be faded to
the next. The two-scene preset is the most common preset board. Cues are manually
set on alternate scene banks and faded from one to the other. Multi-scene preset
boards can also be found in some permanent installations which can require
multiple operators to preset.
Programming
The process by which light cues are set-up, written, and recorded into memory
on a memory console. Programming on contemporary control consoles may involve
complex manipulation of functions and software, but rarely involves actual
program coding.
See Also: Computer Memory Console Light Cue
Protocol
An electronic communication signal by which the electronic devices in a lighting
system can share information. Standard lighting protocols include AMX, DMX,
MIDI, as well as many proprietary protocols utilized by specific manufacturers.
R
Rigger
A technician chiefly responsible for the rigging for a production. Riggers
often work in teams of two so that one can assist from the ground and keep
watch for ground obstacles while the other rigger works in a lift or in the
ceiling structure of the venue. They often have separate calls from the main
crew.
Rigging
The process by which scenery, truss, or other equipment is flown on aircraft
cable or chain. Also refers to the equipment used.
Road Crew
Technical crew members who travel with a production on tour.
Roboscan (TM)
A moving mirror automated fixture manufactures by Martin.
See Also: Moving Mirror Automated Fixture
Rolling Rack
A portable dimmer rack on casters for ease of transportation.
S
Saturation
The purity of a color, or with spectral colors, how much of a color is near
the dominant wavelength. Primary colors are very saturate, while pale tones
are said to be desaturated.
Save
Lighting design shorthand for "take a channel to a level of zero." Not
to be confused with the term [Record] used to store a cue in a computer console's
memory.
Scene Machine (TM)
A special effects projector manufactured and marketed by The Great American
Market. Different effects heads are available for the Scene Machine such as
the motor driven film loop, rotating disc effects, etc.
SCR (Silicon Controlled Rectifier)
A solid state electronic remote controllable dimming device. An SCR is essentially
an electronic switch which achieves the affect of dimming by turning an electrical
circuit on and off rapidly over a specific time interval. Most SCR dimmers
can only be used to dim incandescent lamps. Other electronic dimmers use similar
devices under other names such as the SSR, and include many other sophisticated
electronic filtering, control, and circuit monitoring and protection circuitry.
Scrim
One of many types of woven gauze-like scenic materials. A scrim will appear
as opaque when lit primarily from in front, or can become transparent when
objects are lit behind it.
Shutter
A metal plate or cutter placed at the gate of an ERS (or less commonly within
an automated fixture or followspot) that allows a portion of the beam to be
cut away or eliminated.
Shutter Cut
The resulting effect of positioning a shutter within an ERS. Shutter cuts are
often made to eliminate unwanted parts of the field of light which may hit
scenery or into the audience.
Side Light
Light which comes primarily from the side of the actor or object being lit.
Strong side lighting is associated with the emphasis of the edges or sides
of actors or objects tending to enhance their dimensionally.
SMPTE (Society of Motion Picture and Television Engineers)
A timing signal used primarily to synchronize video, film, and audio recording
and playback systems. SMPTE timecode is measured in hours, minutes, seconds,
and frames. Some lighting control consoles can be set up to read SMPTE time
code--automatically executing cues at specific times. SMPTE or other time-code
systems including MIDI timecode (MTC) are commonly used in completely automated
shows such as those found at theme parks to keep lighting, sound, and motion
control systems in sync.
Socapex (TM)
A multicable and connector system whereby cables from multiple female power
connectors are wound into a single connector, called a fan-in, connected to
a multicable
cable. At the other end of the multicable another connector, a fan-out, divides
the cables into corresponding male power connectors. Often the other end is
simply connected directly to the dimmer.
Soft Patch
A component of most computer memory consoles that allows dimmers to be patched
electronically to control channels within the system. Generally multiple dimmers
can be patched to single control channels, but a dimmer can not be patched
to more than one control channel. As a greater variety of other types of devices
are attached to systems primarily designed to control only dimmers, the relationship
of control channels to dimmers becomes increasingly abstract. A dimmer in the
system may actually represent a function of an automated fixture or a control
for a strobelight or fog machine.
Solo
A mode affecting bump buttons on a lighting control console. When a bump button
is in solo mode it will momentarily take all channels except those assigned
to the bimp button to zero.
Span Set
A loop of nylon webbing wrapped around load bearing structures at the points
to which it will be rigged.
Spider
A circuiting device that allows multiple lighting instruments to be combined
into a single circuit or cable.
Stage Cable
A cable used to connect lighting instruments to circuits or dimmer racks. Standard
stage cable is type SO, 12 gauge, 3 conductor cable. This is abbreviated as
12/3 SO.
Strike
The process by which the scenery and lighting equipment for a show is permanently
disassembled when the tour or production closes.
Strobe Cannon
A type of strobelight mounted in a PAR64 housing. Some strobe cannons, such
as the Diversitronics model, can be remotely controlled via a DMX control signal.
Strobelight
A special lighting effect which produces multiple rapid bursts of high intensity
light. Strobe lighting is almost always produced by a compact xenon strobe
lamp activated by a power supply and timing circuitry. Strobelights can be
simple low power devices with fixed flash rates, or sophisticated devices triggered
by a lighting control console at specific intervals.
T
Three-fer
A circuiting device which allows three lighting instruments to be joined into
one cable or circuit.
Tie-in
The process of connecting dimmer rack feeder cable to house panels, another
power distro or generator.
Tie-in Set
A set of feeder cables or other necessary connecting devices needed to tie-in
a dimmer rack. A standard tie-in set includes a ground, neutral, and three
hot cables with bare-ends in one end for connection at the company switch or
disconnect panel.
Triangle Truss
A triangular shaped truss such as that used for radio towers. Triangle truss
has the disadvantage over box truss that instrumentation must be struck from
the truss before it can be loaded into a truck.
Truss
A steel or aluminum structure used for rigging stage lighting instruments,
scenery, or other equipment for temporary use.
Tungsten Halogen Lamp
A classification of incandescent lamps in which the quartz glass envelope (or
bulb) is filled with a halogen gas. Advantages over standard incandescent lamps
include longer lamp life and the ability to create much more compact filament
designs. Tungsten-halogen lamps typically burn at much higher temperatures
than their plain incandescent counterparts.
Twist-lock
A standard connector for stage cable.
Two-fer
An electrical connecting device which allows two lighting instruments to be
combined into one cable or circuit.
U
Ultra Violet (UV)
An ultraviolet light source used to create special lighting effects with fluorescent
materials. UV sources can be incandescent, fluorescent, or preferably HID
lamps.
Union House
A venue that is a union house, holds a collective bargaining agreement with
its union employees guaranteeing such things as pay scale, working hours and
conditions. If a theatrical venue is a union house it is most likely covered
by I.A.T.S.E.
V
Venue
A local theatre or arena where a touring show will load-in.
Voltage
The electric potential which exists between two components in an electrical
system. Lamps are rated in terms of wattage at a specific voltage. Operating
a lamp at another voltage from that which it is rated may cause the lamp to
burn at less than full intensity or to burn out very quickly.
W
Wattage
The measurement of the amount of power used by an electrical device. Lamps
are rated in terms of wattage. Dimmers are rated in terms of their maximum
load capacity in wattage. Wattage=Amperage*Voltage.
Wiggle Light
Somewhat derogatory term for an automated fixture.
Wire Rope
Stranded steel cable similar to aircraft cable.
X
Xenon
A type of enclosed arc lamp which is commonly used in strobelights. It creates
short bursts of bright high color temperature light. Some xenon lamps, combined
with special power supplies create continuous output and are used in followspots.
Xenon lamps are not generally dimmable.
See Also: Followspot Strobelight
|
