A parabolic aluminized reflector lamp (also PAR light, PAR can, or simply PAR) is a type of electric lamp that is widely used in commercial, residential, and transportation illumination. Usage includes locomotive headlamps, aircraft landing lights, and residential and commercial recessed light

Recessed light

A recessed light or downlight is a light fixture that is installed into a hollow opening in a ceiling...

s ("cans" in the United States). They are identical in principle to sealed beam

Sealed beam

A sealed beam is a type of lamp that includes a reflector and filament as a single assembly, over which a front cover of clear glass, is permanently attached. Previously, automotive headlamps used a separate small bulb and reflector covered with a ribbed lens to avoid glare from the filament. This...

 automobile headlights.

This article covers only their use in stage lighting

Stage lighting

Modern stage lighting is a flexible tool in the production of theatre, dance, opera and other performance arts. Several different types of stage lighting instruments are used in the pursuit of the various principles or goals of lighting. Stage lighting has grown considerably in recent years...

. The lamps and their fixtures are widely used in 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...

, concerts and motion picture production when a substantial amount of flat lighting is required for a scene

Scene (film)

In TV and movies, a scene is generally thought of as the action in a single location and continuous time. Due to the ability to edit recorded visual works, it is typically much shorter than a stage play scene....

.

In situations where sunlight

Sunlight

Sunlight, in the broad sense, is the total frequency spectrum of electromagnetic radiation given off by the Sun. On Earth, sunlight is filtered through the Earth's atmosphere, and solar radiation is obvious as daylight when the Sun is above the horizon.When the direct solar radiation is not blocked...

 or other specular light is available, a white foam reflector

Reflector (photography)

In photography and cinematography, a reflector is an improvised or specialised reflective surface used to redirect light towards a given subject or scene.- Types :...

 is often used to accomplish the same effect as a PAR array.

PAR cans are being replaced in some applications by LED PAR cans

LED stage lighting

LED stage lighting instruments are stage lighting instruments that use light-emitting diodes as a light source. LED instruments are an alternative to traditional stage lighting instruments which use halogen lamp or high-intensity discharge lamps...

, which use less electric power

Electric power

Electric power is the rate at which electric energy is transferred by an electric circuit. The SI unit of power is the watt.-Circuits:Electric power, like mechanical power, is represented by the letter P in electrical equations...

 and produce a wide array of saturated colors without the use of color filters, when white light is not needed.

Construction

PAR lights possess a 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...

 and reflector that are integral parts of the lamp, the position of which cannot be altered relative to the filament. A notable exception is ETC's

Electronic Theatre Controls

Electronic Theatre Controls is a privately held corporation with global headquarters in Middleton, Wisconsin, United States. An international manufacturer of entertainment and architectural lighting systems, ETC offers professional lighting fixtures, lighting control consoles, dimming equipment...

 Source Four PAR

Source Four PAR

The Source Four PAR is a lighting fixture manufactured by Electronic Theatre Controls as a modern, energy efficient alternative to the traditional Parabolic aluminized reflector fixtures.-Construction:...

, which uses the same halogen lamp

Halogen lamp

A halogen lamp, also known as a tungsten halogen lamp, is an incandescent lamp with a tungsten filament contained within an inert gas and a small amount of a halogen such as iodine or bromine. The chemical halogen cycle redeposits evaporated tungsten back on to the filament, extending the life of...

 as their Source Four ERS. In this case, the lens is a separate piece from the lamp. The relative position of lamp and lens remains unalterable.

In PAR 64s, Raylite reflectors and two pin base lamps are often used as a cheaper alternative as the lamp is replaced but the reflector remains. Lamps such as the 500 watt A1/244 can be as much as half the price of the sealed beam units. Par 64's also often run at 120 V, in two-pair series channels, with a "y" Splitter at the dimmer. Narrow, medium and wide Raylite reflectors are quite readily available. The two-blade (pin) Mogul lamp connector need not be replaced — this is integral to the Raylite reflector, 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).

Effects

The sealed beam lamp produces an intense oval pool of light with unfocused edges. The only focus adjustment is a knob that allows the lamp/lens unit to be rotated within its casing, thus changing the orientation of the oval. With some models this control is via the mogul ceramic connector which connects directly to the Mogul prongs of the lamp. With the SourceFour PAR, the interchangeable lens is what is rotated. Therefore, the diameter of the light spot is defined by the aluminium
reflector, and cannot be adjusted without changing the lamp. The type of lamp includes extra-wide flood (XWFL), wide flood (WFL), medium flood (MFL), narrow spot (NSP), and very narrow spot (VNSP).

These types of instruments come in varying diameters, the most common being designated PAR56 and PAR64. The number indicates the diameter of the housing in eighths of an inch (so a PAR64 is eight inches (~20 cm) in diameter).

Uses

PAR lights are often used in theatrical or live music shows. Commonly they are used to generate colours by fitting them with colored sheets called gels

Color gel

A color gel or color filter , also known as lighting gel or simply gel, is a transparent colored material that is used in theatre, event production, photography, videography and cinematography to color light and for color correction...

. The cans are arranged into rows of different colours and identical rows placed on different sides of the stage. Due to their affordability, they are ideal for colour washes in several different colours. However, because of the lack of control over the beam diameter, shape and sharpness, PARs are rarely used as front of house

Front of House

Front of house is primarily a theatrical term, referring to the portion of the building that is open to the public. In theatre and live music venues, it typically refers to the auditorium and foyer, as opposed to the stage and backstage areas...

 lights other than for front washes but can be used for special effect

Special effect

The illusions used in the film, television, theatre, or entertainment industries to simulate the imagined events in a story are traditionally called special effects ....

 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.

Diameter

Nominal lamp bell diameter in inches is found by dividing the PAR size by 8. For example, a PAR30 lamp is approximately 3.75 inches in diameter.

Designation	Nominal Dia. (inch)	Nominal Dia. (mm)
PAR64	8	200
PAR56	7	175
PAR46	5.75	145
PAR38	4.75	120
PAR36	4.5	115
PAR30	3.75	95
PAR20	2.5	65
PAR16	2	50

Note: PAR16 is also known as a "birdie" in theatre, as it is "below par", an oblique reference to a term used in the game of golf

Golf

Golf is a precision club and ball sport, in which competing players use many types of clubs to hit balls into a series of holes on a golf course using the fewest number of strokes....

.

Beam width

Depending the parabolic reflector geometry and placement of the filament within the paraboloid, PAR lamps can achieve a wide range of beam widths, from narrow spot to wide flood. For lighting effects even wider than wide flood can provide, supplemental reflectors or lenses can be used. The following suffixes are commonly used with PAR lamps to indicate their beam width:

Description	Suffix
Very Narrow Spot	CP60
Narrow Spot	CP61
Medium Flood 1	CP62
Wide Flood	CP95

Standard Power Ratings

PAR64

• 1000 W
• 500 W
• 250 W (ACL)

PAR56

• 500 W
• 300 W
• 200 W

PAR38

• 150 W
• 100 W
• 75 W

Each lamp type is available in 110 V or 220 V rating, depending on the common mains voltage for a locale, except ACL PAR, whose light beam is more compact and nominal operating voltage is 28 V. ACL PAR is a type of projector primarily used in aviation, before being used on stage for light path effects. In the UK, ACL pars are typically used together with four mounted together on a bar, and two bars run in series together in order to work on a dimmer with 240v supply voltage.
In Europe, where the mains voltage is between 220 and 240v, it is common to use series pairs of 110v lamps because the thicker filament is much less liable to vibration-induced fracture; an important consideration for touring rigs and music venues.

Raylite reflector

Raylite reflectors can be added to PAR64 and PAR56 lamp housings to achieve a narrow spot effect. A conventional quartz halogen lamp is used in place of the reflector lamp. A spider or bulb shield may optionally be added, which enhances the parallel nature of the beam and makes it more visible when used with smoke or fog effects. Raylites are generally less rugged than sealed beam bulbs. The lamp can easily shake loose of the lampholder in transit.

Finish

PARs are found commonly with either black finish or polished (silver). PARs can occasionally be found in white.

Non-sealed PAR alternatives

The Source Four PAR and similar units create light with a similar quality to that of a PAR can, but have lenses separate from the lamp.

LED

An LED

Light-emitting diode

A light-emitting diode is a semiconductor light source. LEDs are used as indicator lamps in many devices and are increasingly used for other lighting...

 version of the PAR is made by some manufacturers.

LED PAR cans usually are based on an RGB color model

RGB color model

The RGB color model is an additive color model in which red, green, and blue light is added together in various ways to reproduce a broad array of colors...

.

PARbars

PARbars are PARs that are permanently affixed to and circuited through an aluminum pipe. Four PARs on a bar are called a 4-bar. 6 PARs are called 6-bars. Typically mains multicore cabling will be used to supply power to the bars, so that only one connection has to be made, thus saving assembly time and giving a neater appearance.

Daylight PARs

HMI

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...

 PARs produce light with a color temperature equivalent to that of sunlight.

PAR movers

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 fixtures, which use a different light source and offer more control over the colour and shape of the beam.

Combination instruments

• The Source Four PARnel combines the attributes of the PAR can and the 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....
  
  .
• OmniSistem makes a "Profile PAR", combining the attributes of the PAR can and an ellipsoidal reflector spotlight.