A parabolic aluminized reflector lamp (PAR lamp or simply PAR) is a type of electric lamp that is widely used in commercial, residential, and transportation illumination. It produces a highly directional beam. Usage includes
theatrical lighting
Stage lighting is the craft of lighting as it applies to the production of theater, dance, opera, and other performance arts. ,
locomotive headlamp
Trains include a variety of types of lights, for safety, illumination, and communicating train status. The most universal type of light is the Headlamp, headlight, which is included on the front of locomotives, and frequently on the rear as well. ...
s, aircraft landing lights, and residential and commercial
recessed light
A recessed light or downlight (also pot light in Canadian English, sometimes can light (for canister light) in American English) is a light fixture that is installed into a hollow opening in a ceiling. When installed it appears to have light shi ...
s ("cans" in the United States).
Many PAR lamps are of the sealed beam variety, with a
parabolic reflector, one or more
filaments, and a glass or plastic lens sealed permanently together as a unit. Originally introduced for road vehicle
headlamp
A headlamp is a lamp attached to the front of a vehicle to illuminate the road ahead. Headlamps are also often called headlights, but in the most precise usage, ''headlamp'' is the term for the device itself and ''headlight'' is the term for ...
service, sealed beams have since been applied elsewhere. Halogen sealed beam lamps incorporate a
halogen lamp
A halogen lamp (also called tungsten halogen, quartz-halogen, and quartz iodine lamp) is an incandescent lamp consisting of a tungsten filament sealed in a compact transparent envelope that is filled with a mixture of an inert gas and a small ...
within a quartz or hard glass envelope.
Construction
![ParHeadlamp](https://upload.wikimedia.org/wikipedia/commons/3/35/ParHeadlamp.jpg)
A PAR lamp consists of a light source, with lens and a parabolic reflector with a smooth aluminium surface determining the spread of the beam. The most common sealed beam type combines these three elements into an integral unit. The light source usually approximates a
point source
A point source is a single identifiable ''localised'' source of something. A point source has negligible extent, distinguishing it from other source geometries. Sources are called point sources because in mathematical modeling, these sources can ...
that can be focused on; tungsten filaments and halogen lamps are common, but some theatrical usage that requires a higher color temperature may use
hydrargyrum medium-arc iodide
Hydrargyrum medium-arc iodide (HMI) is the trademark name of Osram's brand of metal-halide gas discharge medium arc-length lamp, made specifically for film and entertainment applications. ''Hydrargyrum'' comes from the Greek name for the eleme ...
(HMI) instead.
Sizes
PAR lamps come in a variety of standardized sizes. The size of a round PAR lamp is expressed as the nominal diameter of the mouth of the reflector, in eighths of an inch—so the approximate nominal lamp bell diameter in inches can be found by dividing the PAR size by 8. A PAR56, for example, is 56 eighths of an inch (7 inches) in diameter; a PAR36 is 36 eighths (4.5 inches) in diameter, and so on. Similarly, the diameter in millimeters can be found by multiplying the PAR designation by 3.125. For example, a PAR16 lamp is approximately 2 inches or 50.0 mm in diameter.
The size of rectangular PAR lamps is expressed as the letters REC followed by the reflector's mouth height, the letter "X", and the reflector's mouth width—with both dimensions in millimeters. For example, REC142X200 lamps are 142 high and 200 mm wide.
Light beams
Depending on the parabolic reflector geometry, the configuration of the filament and its placement within the paraboloid, PAR lamps can achieve a wide range of beams, from narrow spot to wide flood. The following suffixes are commonly used with PAR lamps to indicate their beam width:
PAR lamps are also manufactured to produce beam patterns specific to the needs of particular applications, such as low beam and/or high beam
headlights
A headlamp is a lamp attached to the front of a vehicle to illuminate the road ahead. Headlamps are also often called headlights, but in the most precise usage, ''headlamp'' is the term for the device itself and ''headlight'' is the term for ...
and
fog and driving lights for vehicles, and warning lamps for
school bus
A school bus is any type of bus owned, leased, contracted to, or operated by a school or school district. It is regularly used to transport students to and from school or school-related activities, but not including a charter bus or transit bus ...
es.
The suffixes given are for 1000-Watt PAR64 lamps only. The focused beam can be oval and is sometimes specified in two numbers.
[
]
Uses
Automotive headlamps
In the United States of America, sealed-beam headlamps were introduced in 1939, becoming standard equipment across all American-market vehicles starting in 1940 and remaining the only type allowed for almost four and a half decades, until the 1984 model year. Before and after those years, vehicles could have model-specific, nonstandard-shape headlamps, using any of a wide variety of replaceable light bulbs. Between 1940 and 1956, all U.S. cars had to have two round headlamps with dual filaments, so each lamp provided both a high and a low beam light distribution. In 1957, a system of four sealed-beam headlamps—two per side, of diameter, was allowed in some U.S. states. The following year in 1958, all states allowed the new system. Two of the lamps contained two filaments and served as low and high beam, while the other two lamps contained only one filament and were active only during high-beam operation.
From the 1975 model year
The model year (sometimes abbreviated "MY") is a method of describing the version of a product which has been produced over multiple years. The model year may or may not be the same as the calendar year in which the product was manufactured.
...
, a rectangular version of the four-lamp system was legalized. The new lamps were wide and tall. For 1978, a rectangular version of the two-lamp system became legal; these measured wide and tall.
With only two round and two rectangular lamp sizes allowed, the sealed-beam headlamp mandate greatly restricted styling possibilities for automobiles.
Halogen
The halogens () are a group in the periodic table consisting of five or six chemically related elements: fluorine (F), chlorine (Cl), bromine (Br), iodine (I), astatine (At), and tennessine (Ts). In the modern IUPAC nomenclature, this group is ...
sealed-beam headlamps appeared on U.S. cars in 1979, to enable greater high beam intensity newly permitted by Federal Motor Vehicle Safety Standard 108 Federal Motor Vehicle Safety Standard 108 (FMVSS 108) regulates all automotive lighting, signalling and reflective devices in the United States. Like all other Federal Motor Vehicle Safety Standards, FMVSS 108 is administered by the United States ...
without unreasonably high lamp wattage. Eventually, halogen sealed-beam lights came to dominate the (U.S.) automotive lamps market.
Aircraft
Aircraft landing (ACL) lights are often sealed beams that have a very narrow beam
Beam may refer to:
Streams of particles or energy
*Light beam, or beam of light, a directional projection of light energy
**Laser beam
*Particle beam, a stream of charged or neutral particles
**Charged particle beam, a spatially localized grou ...
spread. They typically have a size of PAR36 or PAR64, and run on 28 V DC. They have found some use in stage lighting as well.
Outdoor and stage lighting
PAR lamps and their fixtures are widely used in theatre, concerts
A concert is a live music performance in front of an audience. The performance may be by a single musician, sometimes then called a recital, or by a musical ensemble, such as an orchestra, choir, or musical band, band. Concerts are held in a w ...
and motion picture production
Production may refer to:
Economics and business
* Production (economics)
* Production, the act of manufacturing goods
* Production, in the outline of industrial organization, the act of making products (goods and services)
* Production as a stati ...
when a substantial amount of flat lighting is required for a scene
Scene (from Ancient Greek, Greek σκηνή ''skēnḗ'') may refer to:
Arts, entertainment, and media Music
*Scene (subculture), a youth subculture from the early 2000s characterized by a distinct music and style. Groups and performers
* The S ...
. They are often mounted in can-shaped fixtures known as PARCANs, which can be used to generate colours by fitting them with colored sheets called gels
A gel is a semi-solid that can have properties ranging from soft and weak to hard and tough. Gels are defined as a substantially dilute cross-linked system, which exhibits no flow when in the steady-state, although the liquid phase may still di ...
. The cans are arranged into rows of different colours and identical rows placed on different sides of the stage; such assemblies made from aluminum bars are known as PARbars. Due to their affordability, they are ideal for colour washes in several different colours. However, because of the lack of dynamic control over the beam diameter, shape and sharpness, PARs are rarely used as Front of House
In the performing arts, front of house (FOH) is the part of a performance venue that is open to the public. In theatres and live music venues, it consists of the auditorium and foyers, as opposed to the stage and backstage areas. In a theatre, t ...
lights other than for front washes but can be used for special effect
Special effects (often abbreviated as SFX, F/X or simply FX) are illusions or visual tricks used in the theatre, film, television, video game, amusement park and simulator industries to simulate the imagined events in a story or virtual wor ...
lighting such as lighting from directly above or from extreme angles as well as general wash lights overhead/above stage. If used cleverly, par cans can provide low budget productions with good effects.
PAR64 sealed beam lamps are often used for these purposes; they are typically available with 250, 500 or 1000 watt power ratings. Beam spreads are designated as FL (flood
A flood is an overflow of water ( or rarely other fluids) that submerges land that is usually dry. In the sense of "flowing water", the word may also be applied to the inflow of the tide. Floods are an area of study of the discipline hydrol ...
), SP (spot
Spot or SPOT may refer to:
Places
* Spot, North Carolina, a community in the United States
* The Spot, New South Wales, a locality in Sydney, Australia
* South Pole Traverse, sometimes called the South Pole Overland Traverse
People
* Spot (prod ...
), NSP (narrow spot), and VNSP (very narrow spot), as stamped on the back of the lamp's reflector.
PAR38 lamps, with an E22 base and with ratings up to 150W, were often used for domestic outdoor floodlight illumination for patios, backyards, and often combined with a PIR sensor switch as a security/convenience light, for example, in a driveway. Coloured versions were popular with discos and mobile DJs, however were usually only available up to 100w in coloured form and were considerably more expensive than standard PAR38 globes. In domestic applications, halogen and later on LED largely replaced the incandescent PAR38.
In situations where sunlight
Sunlight is a portion of the electromagnetic radiation given off by the Sun, in particular infrared, visible, and ultraviolet light. On Earth, sunlight is scattered and filtered through Earth's atmosphere, and is obvious as daylight when t ...
or other specular
Specular reflection, or regular reflection, is the mirror-like reflection of waves, such as light, from a surface.
The law of reflection states that a reflected ray of light emerges from the reflecting surface at the same angle to the surfac ...
light is available, a white foam reflector is often used to accomplish the same effect as a PAR array. PAR cans are being replaced in some stage applications by LED stage lighting
LED stage lighting instruments are stage lighting instruments that use light-emitting diodes (LEDs) as a light source. LED instruments are an alternative to traditional stage lighting instruments which use halogen lamp or high-intensity discharge ...
, which use less electric power
Electric power is the rate at which electrical energy is transferred by an electric circuit. The SI unit of power is the watt, one joule per second. Standard prefixes apply to watts as with other SI units: thousands, millions and billions o ...
and produce a wide array of saturated colors without the use of color filters, when white light is not needed.
Indoor lighting
Smaller sealed beam PAR lamps (PAR 38 and smaller) with an Edison screw
Edison screw (ES) is a standard lightbulb socket for electric light bulbs. It was developed by Thomas Edison (1847–1931), patented in 1881, and was licensed in 1909 under General Electric's Mazda trademark. The bulbs have right-hand threaded ...
base are common in indoor lighting. They can be found in recessed fixtures mounted in the ceiling or on track
Track or Tracks may refer to:
Routes or imprints
* Ancient trackway, any track or trail whose origin is lost in antiquity
* Animal track, imprints left on surfaces that an animal walks across
* Desire path, a line worn by people taking the shorte ...
s.
Lighthouses
Sealed beam lamp arrays are also in use by modern lighthouse
A lighthouse is a tower, building, or other type of physical structure designed to emit light from a system of lamps and lenses and to serve as a beacon for navigational aid, for maritime pilots at sea or on inland waterways.
Lighthouses mar ...
s.
Electrical connector
High-power, mains-voltage, theatrical PARs usually use the bi-pin GX16d "Mogul" lamp connector; G9.5 and variants are common too. Theater metal-halide lamps use G12. In addition to being used on light bulbs themselves, the G38 connectors are also found as a part of the Raylite reflector assembly, although some Raylite reflectors have "tails" which then require connection to the mains flex with the use of a ceramic connector block (ideally fixed to the can's body).
In residential and office use, the usual connector for the lamp's voltage is often used. This includes Edison screw or a bayonet connector for mains-supplied PARs, or small bi-pin connectors for low voltage applications.
Variations
LED
LED
A light-emitting diode (LED) is a semiconductor Electronics, device that Light#Light sources, emits light when Electric current, current flows through it. Electrons in the semiconductor recombine with electron holes, releasing energy i ...
retrofit equipment that match PAR lamp dimensions is made by some manufacturers. As with the case of LED MR lamps, LED PAR lamps generally use an array of individual LED elements that are unsuitable for reflector operation. Nevertheless, some degree of beam control can be obtained with aperture or lens, and LED PAR 38 replacements with a 40° spread is common.
Models built for stage lighting may use less similar dimensions. They often use a RGB color model
The RGB color model is an additive color model in which the red, green and blue primary colors of light are added together in various ways to reproduce a broad array of colors. The name of the model comes from the initials of the three additiv ...
for color-tuning abilities, though some higher-end fixtures use a 5-primary colour system (with cool and warm white LEDs) instead for better color reproduction.
PAR moving lights
Intelligent, moving PARs allow for the ability to pan and tilt the instruments through a lighting control console. These have been generally superseded by dedicated intelligent lighting
Intelligent lighting refers to 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 l ...
fixtures, which use a different light source and offer more control over the colour and shape of the beam.
See also
*Stage lighting instrument
Stage lighting instruments (lanterns, or luminaires in Europe) 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 st ...
*Stage lighting accessories Stage lighting accessories are components manufactured for conventional (non-automated) stage lighting instruments. Most conventional fixtures are designed to accept a number of different accessories designed to assist in the modification of the out ...
Notes
References
{{Artificial light sources
Cinematography
Incandescent light bulbs
Stage lighting instruments
Automotive lamps