 |
|
|
|
 |
|
||
 |
 |
 |
|
 |
|
||
|
|
|
|
|
|
||
|
|
|
|
|
|
||
There is a number of interesting lighting facts within this page but if you have something you can contribute please email your info CLICK HERE
General stage Lighting - Lighting Instruments - Floodlights - Spotlights - Where does the fresnel come from? - Fresnel lens - Parabolic?
- What Is Light? - The Light Wave Theory - Speed Of Light - Photon Model Of Light - What is an Opto-Isolator? - Colour Mixing; additive and subtractive -
- Chookas; Break-a-Leg - Cyclorama -
Modern stage lighting is a flexible tool in the production of theatre, dance, opera and other performance arts. Several different types of lighting instrument are used in the pursuit of the various principles or goals of lighting. These Principles of Lighting include:
* Illumination: The simple ability to see what is occurring onstage.
* 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.
* Location and Time of Day: Establishing or altering position in time and space.
* Projection/Stage Elements: Lighting may be used to project scenery or to act as scenery onstage.
* Plot: A lighting event may trigger or advance the action onstage.
In the pursuit of the Principles of Lighting, the three main Qualities or Properties of interest are:
* Intensity: Measured in both lux and lumens. For any given luminaire (lighting instrument or fixture), this depends upon the power of the bulb, the design of the instrument (and its corresponding efficiency), the presence or absence of color gels or gobos, distance from the area to be lit, the color and subtance to be lit, and the neuro-optics of the total scene (that is, the relative contrasts to other regions of illumination).
* Color: Color temperature is measured in kelvin, and gel colors are organized by several different systems maintained by the color manufacturing companies. The apparent color of a light is determined largely by the gel color given it, but also in part by the power level the lamp is being run at and the color of material is it to light. As the percentage of full power a lamp is being run at drops, the tungsten filament in the bulb glows orange instead of more nearly white. This is known as Amber Drift. Thus a 1000-watt instrument at 50% will appear far more orange than a 500-watt instrument at full.
* Pattern: Pattern refers to the shape, quality and evenness of a lamp's output. The pattern of light an instrument makes is largely determined by three factors. The first are the specifics of the bulb, reflector and lens assembly. Different mounting positions for the bulb (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) and their derivatives, 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 ERS's and similar lamps. This is typically a strip of metal with a shape cut into it. It is inserted into the lamp near its aperture. Gobos come in many shapes, but often include leaves, waves, stars and similar patterns.
In addition to these, certain modern instruments are 'movable' (AKA: 'intelligent'), referring to motorized movement of either the entire lamp or a mirror placed in front of its outermost lens. These lamps and the more traditional follow spots add Direction to the relevant characterists of light.
It is important to note that 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.
The above elements of lighting are primarily the domain of the lighting designer (LD). In consultation with the director and the scenic or stage designer and after watching sufficient late rehearsals, the LD is responsible for providing an Instrument Schedule and a Lighting Plot. The Schedule is a list of all required materials, including gel colors, gobos, color wheels, barndoors and other accessories. The lighting plot is typically a plan view of the theatre in which the performance will take place, with every luminaire marked, including its 'rough' focus (the direction it should be pointing), its instrument number, any color/gobo/accessories required, and the specifics of its connection to the lighting control systems (channel number). These form the basis of the work the Lighting Crew is to undertake, under the supervision of the Head Electrician and the direction of the Crew Chief.
Lighting Instruments Back to top
There are a variety of instruments frequently used on the stage.
It is important to note that virtually all theatrical bulbs are incandescent. Fluorescent lights are rarely used outside of work lights because, although they are far more efficient, in most cases they cannot be 'dimmed' (run at less than full power), they do not produce light from a 'point' or easily concentrated area, and have a warm-up period, during which they emit no light or do so intermittently. Until recently (1990s), carbon arc lamps were common in high power follow spots. Carbon arc follow spots have been largely replaced by high-intensity xenon or halogen instruments.
Floodlights Back to top
PAR Cans (parabolic aluminized reflector) These resemble car headlights. They possess a lens, but it is an integral part of the lamp housing, and its position relative to the filament cannot be altered.
The lamp produces an intense oval pool of light with soft edges. The only adjustment is a knob that allows the lamp unit to be rotated within its casing, thus changing the orientation of the oval. There is available varing types of lamps that have different lenses that can narrow or widen thes beam angle. The most common of these are WFL (wide Flood), MFL (medium flood), NSP (narrow spot), VNSP (very narrow spot).
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 (eg a PAR64 is eight inches in diameter).
Because of the lack of control over beam diameter, shape and sharpness, PAR Cans are seldom used in theatre (except for special purpose) but are used extensively at rock concerts, especially in combination with smoke/haze machines which make the path of the beam visible.
Strip or Cyclorama (Cyc) lights These are long housings typically containing multiple bulbs arranged along the length of the instrument and emitting light perpendicular to its length. The strip light housing often contains bulbs of multiple colors (usually the primary colors) with each color controlled by a separate electrical circuit. Varying the intensity of the different colors enables the lighting designer to establish mood or time of day.
House lights and Work lights House lights are incandescent or fluorescent floodlights. House lights provide light for the audience before and after performances and during intermissions. Work lights provide general lighting backstage, or in the house. House lights are often controlled by dimmers, but are sometimes on simple switches. Work lights are almost always switched only. House and work lights are usually off during performances but are occasionally included in the lighting design to establish focus or emphasize plot elements.
Spotlights Back to top
* Fresnels
* Ellipsodial Reflector Spotlights
* Paralipspheres
Fresnel: Fresnels are typically 6 or 4 inch, referring to the diameter of the lens. The lens is the distinctive 'Fresnel lens' type, with a 'stepped' appearance instead of the 'full' or 'smooth' appearance of other lenses. The stepped nature of the lens causes a corresponding pattern of circles of light, so Fresnel lenses are usually 'stippled' on the flat side. This pattern of small bumps helps to break up the light passing into the lens to smooth out its eventual pattern.
Fresnels use a parabolic reflector, with the filament of the bulb at the focus. Due to this, the bulb and reflector cannot move independently of one another, and remain a fixed unit inside the housing. It is this unit that is moved back and forth inside the lamp to focus the fresnel. This is done by a slider on the bottom of the light, or by a worm track.
Fresnels are not very efficient. The reflector cannot be larger than then lens aperture, and thus all the radiated light that is neither reflected by the parabola behind the bulb or emitted directly through the lens is absorbed by the casing as waste heat. Additionally, the degree to which the lamp may be focused is limited by the length of the housing. The tighter the focus ('spotted in') the less light is able to escape. Thus fresnels are not good for tight focus on small areas. Fresnels also lack internal shutters, and must rely on barndoors, large metal flaps that may be mounted just beyond the color slot at the front of the light. Due to these restrictions, Fresnels are most often used at middling distances for area lighting. Fresnel bulbs are almost always 'base down': mounted with the bulb up.
ERS: The Ellipsoidal Reflector Spotlight is also sometimes known as a 'Leko'. It comes in very many forms, and is the most numerous and important instrument type in use. The flexability of the ERS allows them to fulfill the bulk of the lighting roles in the theatre, from area lighting to close specials, from long throws from the back of the house to shin kickers on the stage.
ERSs may have more than one focusing lens, while all possess internal shutters for cropping the emitted light, and all accept a color gel in front of the lens and a gobo in front of the shutters. ERS's may have bulbs mounted axially, or with the base either up or down (it is important to hang a lamp in the proper orientation). The lenses are smooth and full, not stepped, and it is the lens or lenses that move in the ERS, not the bulb and reflector assembly as in the Fresnel.
The ERS improves over the efficiency of the Fresnel by surrounding the bulb in an ellipsoidal reflector, with the filament of the bulb at one focus and the aperture to the lens housing at the other. The shutters and gobo are ideally in focal point of this apature.
Moving lights or Intelligent fixtures: While originally implemented in 1972, the first computer-controlled stage lighting fixtures, called Moving Lights or Intelligent Fixtures, began to gain widespread acceptance in the Concert Industry in the early 1980's. As the digital age progressed, the cost of these fixtures was reduced and they slowly started being used in a more 'traditional' theatrical environment. Intelligent Fixtures are currently used in almost all major theatrical productions.
Usually relying on compact Arc lamps as a light source, these fixtures generally use stepper motors contected to varying internal devices to manipulate the light before it escapes the fixtures front lens.
Examples of internal devices are:
* Color wheels with dichroic lenses used to change the color of the beam.
* Pattern wheels with gobos used to change the shape of the beam.
* Shutters used to 'dim' or 'strobe' the output, automated lens trains used to focus the beam.
* Irises used to change the size of the beam.
* Gate shutters to 'square off' the beam.
* CYM Color-Mixing Wheels using Color-Subtraction technology to vary beam color.
* Prisms
* Etc.
The majority of these fixtures also use stepper motors to enable movement of the light fixtures output by either moving a mirror which reflects the beam, or by moving the entire fixture lens train. This allows the fixture to cover large areas by varying the X-Y coordinates of the beam. Higher performance fixtures use servo controlled motors for pan and tilt motion.
Moving Lights are controlled in many ways. Usually the fixtures are connected to a Lighting Console, which outputs a control signal. This control signal sends data to the fixture in a usually one of three ways - Analog (which has largely been phased out), DMX (which is the industry standard control protocol), or Ethernet Control (which is still in development). The fixture then takes this signal and translates it into internal signals which are sent to the many stepper motors located inside.
Augustin-Jean Fresnel Back to top
Augustin Fresnel
Augustin-Jean Fresnel (pronounced fray-NELL) (May 10, 1788 – July 14, 1827), was a French physicist who contributed significantly to the establishment of the wave theory of light and optics. Fresnel studied the behaviour of light both theoretically and experimentally.
Fresnel was the son of an architect, born at Brogue (Eure). His early progress in learning was slow, and he still could not read when he was eight years old. At thirteen he entered the École Centrale in Caen, and at sixteen and a half the École Polytechnique, where he acquitted himself with distinction. From there he went to the École des Ponts et Chaussées. He served as an engineer successively in the departments of Vendée, Drôme and Ille-et-Villaine; but having supported the Bourbons in 1814 he lost his appointment on Napoleon's return to power. On the second restoration of the monarchy, he obtained a post as engineer in Paris, where much of his life from that time was spent. His researches in optics, continued until his death, appear to have been begun about the year 1814, when he prepared a paper on the aberration of light, which, however, was not published. In 1818 he read a memoir on diffraction for which in the ensuing year he received the prize of the Académie des Sciences at Paris. He was in 1823 unanimously elected a member of the academy, and in 1825 he became a member of the Royal Society of London, which in 1827, at the time of his last illness, awarded him the Rumford Medal. In 1819 he was nominated a commissioner of lighthouses, for which he was the first to construct compound lenses as substitutes for mirrors. He died of tuberculosis at Ville-d'Avray, near Paris.
The undulatory theory of light, first founded upon experimental demonstration by Thomas Young, was extended to a large class of optical phenomena, and permanently established by his brilliant discoveries and mathematical deductions. By the use of two plane mirrors of metal, forming with each other an angle of nearly 180°, he avoided the diffraction caused in the experiment of F. M. Grimaldi on interference by the employment of apertures for the transmission of the light, and was thus enabled in the most conclusive manner to account for the phenomena of interference in accordance with the undulatory theory. With Francois Arago he studied the laws of the interference of polarized rays. Circularly polarized light he obtained by means of a rhombus of glass, known as "Fresnel's rhomb", having obtuse angles of 126° and acute angles of 54°. His labours in the cause of optical science received during his lifetime only scant public recognition, and some of his papers were not printed by the Académie des Sciences till many years after his decease. But, as he wrote to Young in 1824, in him "that sensibility, or that vanity, which people call love of glory" had been blunted. "All the compliments," he says, "that I have received from Arago, Laplace and Biot never gave me so much pleasure as the discovery of a theoretic truth, or the confirmation of a calculation by experiment."
(a) Cross section of a Fresnel lens
(b) Cross section of a conventional plano-convex lens of equivalent power
A Fresnel lens is a type of lens invented by Augustin-Jean Fresnel. Originally developed for lighthouses, the design enables the construction of lenses of large size and short focal length without the weight and volume of material which would be required in a lens of conventional design.
The Fresnel lens (commonly pronounced FREZ-nell but originally fray-NELL) reduces the amount of material required compared to a conventional spherical lens by breaking the lens into a set of concentric annular sections known as Fresnel zones. For each of these zones, the overall thickness of the lens is decreased, effectively chopping the continuous surface of a standard lens into a set of surfaces of the same curvature, with discontinuities between them. This allows a substantial reduction in thickness (and thus weight and volume of material) of the lens, at the expense of reducing the imaging quality of the lens.
Parabolic Back to top
A parabola
A parabola (from the Greek: πÉøÉœÉøÉ¿ÉÕÉ…‹) is a conic section generated by the intersection of a cone, and a plane tangent to the cone or parallel to some plane tangent to the cone. If the plane is itself tangent to the cone, one would obtain a degenerate parabola, a line. A parabola can also be defined as locus of points which are equidistant from a given point (the focus) and a given line (the directrix).
What is light? Back to top
Light is part of the electromagnetic spectrum, the spectrum is the collection of all waves, which include visible light, Microwaves, radio waves ( AM, FM, SW ), X-Rays, and Gamma Rays.
In the late 1600s, important questions were raised, asking if light is made up of particles, or is it waves .?
Sir Isaac Newton, held the theory that light was made up of tiny particles. In 1678, Dutch physicist, Christiaan Huygens, believed that light was made up of waves vibrating up and down perpendicular to the direction of the light travels, and therefore formulated a way of visualising wave propagation. This became known as 'Huygens' Principle'. Huygens theory was the successful theory of light wave motion in three dimensions. Huygen, suggested that light wave peaks form surfaces like the layers of an onion. In a vacuum, or other uniform mediums, the light waves are spherical, and these wave surfaces advance or spread out as they travel at the speed of light. This theory explains why light shining through a pin hole or slit will spread out rather than going in a straight line . Newton's theory came first, but the theory of Huygens, better described early experiments. Huygens' principle lets you predict where a given wavefront will be in the future, if you have the knowledge of where the given wavefront is in the present.
At the time, some of the experiments conducted on light theory, both the wave theory and particle theory, had some unexplained phenomenon, Newton could not explain the phenomenon of light interference, this forced Newton's particle theory in favour of the wave theory. This difficulty was due to the unexplained phenomenon of light Polarisation - scientists were familiar with the fact that wave motion was parallel to the direction of wave travel, NOT perpendicular to the to the direction of wave travel, as light does.
In 1803, Thomas Young studied the interference of light waves by shining light through a screen with two slits equally separated, the light emerging from the two slits, spread out according to Huygen's principle. Eventually the two wave fronts will overlap with each other, if a screen was placed at the point of the overlapping waves, you would see the production of light and dark areas.
Later in 1815, Augustin Fresnel supported Young's experiments with mathematical calculations.
In 1900 Max Planck proposed the existence of a light quantum, a finite packet of energy which depends on the frequency and velocity of the radiation.
In 1905 Albert Einstein had proposed a solution to the problem of observations made on the behaviour of light having characteristics of both wave and particle theory. From work of Plank on emission of light from hot bodies, Einstein suggested that light is composed of tiny particles called photons, and each photon has energy.
Light theory branches in to the physics of quantum mechanics, which was conceptualised in the twentieth century. Quantum mechanics deals with behaviour of nature on the atomic scale or smaller.
As a result of quantum mechanics, this gave the proof of the dual nature of light and therefore not a contradiction.
Light Wave Theory Back to top
Light can exhibit both a wave theory, and a particle theory at the same time. Much of the time, light behaves like a wave. Light waves are also called electromagnetic waves because they are made up of both electric (E) and magnetic (H) fields. Electromagnetic fields oscillate perpendicular to the direction of wave travel, and perpendicular to each other. Light waves are known as transverse waves as they oscillate in the direction traverse to the direction of wave travel.
The Electromagnetic Wave
Waves have two important characteristics - wavelength and frequency.
The Sine Wave
The sine wave is the fundamental waveform in nature. When dealing with light waves, we refer to the sine wave. The period (T) of the waveform is one full 0 to 360 degree sweep. The relationship of frequency and the period is given by the equation:
f = 1 / T
T = 1 / f
The waveforms are always in the time domain and go on for infinity.
Wavelength:
This is the distance between peaks of a wave. Wavelengths are measured in units of length - meters, When dealing with light, wavelengths are in the order of nanometres (1 x 10-9)
Frequency:
This is the number of peaks that will travel past a point in one second. Frequency is measured in cycles per second. The term given to this is Hertz (Hz) named after the 19th century discoverer of radio waves - Heinrich Hertz. 1 Hz = 1 cycle per second
The speed of a wave can be found by multiplying the two units together. The wave's speed is measured in units of length (distance) per second:
Wavelength x Frequency = Speed
The Speed Of Light Back to top
The speed of light in a vacuum is a universal constant, about 300,000 km/s or 186,000 miles per second. The exact speed of light is: 299,792.458 km/s.
It takes approximately 8.3 min for light from the sun the reach the earth ( 150,000,000 / 300,000 / 60 = 8.3 ). Taking the distance of the sun from Earth into account, which is 150,000,000 km, and the fact that light travels at 300,000 km/s, it shows in someway how fast light actually travels.
With the use of the SI units for wavelength (l), frequency (¦) and speed of light (c), we can derive some simple equations relating to wavelength, frequency and speed of light:
l = c / ¦
¦ = c / l
Photon Model of Light Back to top
As proposed by Einstein, light is composed of photons, very small packets of energy. The reason that photons are able to travel at light speeds is due to the fact that they have no mass and therefore, Einstein's infamous equation - E=MC2 cannot be used. Another formula devised by Planck, is used to describe the relation between photon energy and frequency - Planck's Constant (h) - 6.63x10-34 Joule-Second.
E = h¦
or
E = hc / l
E is the photonic energy in Joules, h is Planks constant and f is the frequency in Hz
Opto-Isolator Back to top
What is an Opto Isolator?
In electronics, an optical isolator is a device that uses a short optical transmission path to transfer a signal between elements of a circuit while keeping them electrically isolated -- since the signal goes from an electrical signal to an optical signal back to an electrical signal, electrical contact along the path is broken. In one simple design, an electrical signal at one end triggers an LED, which in turn triggers a photosensor that produces an electrical signal at the other end.
The optical path may be air or a dielectric waveguide. The transmitting and receiving elements of an optical isolator may be contained within a single compact module, for mounting, e.g., on a circuit board; in this case, the module is often called an optoisolator or opto-isolator.
In optics, the term optical isolator is also used for a purely optical device also known as a Faraday isolator.
* A Dielectric Waveguide is a waveguide that consists of a dielectric material surrounded by another dielectric material, such as air, glass, or plastic, with a lower refractive index. An example of a dielectric waveguide is an optical fiber. Paradoxically, a metallic waveguide filled with a dielectric material is not a dielectric waveguide.
* A Faraday isolator or optical isolator is an optical component which allows the transmission of polarised light in only one direction. They are typically used to prevent unwanted feedback into an optical oscillator (A laser cavity is a good example.) The operation of the device depends on the Faraday effect which is used in the main component, the Faraday rotator.
An isolator is made of three parts, an input polarizer (for this discussion we will assume it's polarized up and down), a Faraday rotator, and an output polarizer (we will assume this one is 45° to the right.)
Light traveling in the forward direction becomes polarized (vertically in our case) by the input polarizer. The Faraday rotator will rotate the polarization 45° to the right. The output polarizer will allow all the light to escape and continue.
Light traveling in the backward direction becomes polarized (45°; to the right in this case) by the output polarizer. The Faraday Rotator will rotate the polarization 45° more to the right so that it is horizontally polarized (the rotation is insensitive to direction of propagation) and the input polarizer, which is vertically aligned, will block this light.
Faraday isolators are different from 1/4 wave plate based isolators because it can provide non-reciprocal rotation while maintaining linear polarization which allows higher isolation to be achieved.
Obviously the most important optical element in a Faraday isolator is the Faraday rotator. The characteristics that one looks for in a Faraday rotator optic, include a high Verdet constant, low absorption coefficient, low non-linear refractive index and high damage threshold. Also, to prevent self-focusing and other thermal related effects, the optic should be as short as possible. The two most commonly used materials for the 700-1100nm range are terbium doped borosillicate glass and terbium gallium garnet crystal (TGG). For long distance fiber communication, typically at 1310 nm or 1550 nm, yttrium iron garnet crystals are used (YIG). Commercial YIG based Faraday isolators reach isolations higher than 30 dB.
Colour Mixing Back
to top
Combining the effects of two or more lighting gels:
1) Additive : Focusing two differently coloured
beams of light onto the same area (eg Cyc Floods). Combining colours in this
way adds the colours together, eventually arriving at white. The three primary
colours additively mix to form white, as do the complementary colours.
2) Subtractive : Placing two different gels in front of the same lantern. Subtractive
mixing is used to obtain a colour effect that is not available from stock or
from manufacturers. Because the ranges of colour are so wide, the need for
subtractive mixing is reducing. Combining colours in this way reduces the light
towards blackness. The three primary colours mix subtractively to form black
(or to block all the light)
.
Primaries of Light are RED, GREEN, BLUE
Secondaries of Light are Light
Blue (Cyan), Purple (Magenta) and Yellow
(Amber) - CMY
Primaries of Paint are RED, YELLOW, BLUE
The plcture above shows ADDITIVE colour mixing: three different lanterns focussed on the same area. The primary colours are added together to get close to white.
SUBTRACTIVE colour mixing occurs when you hold more than one colour in front of the same lantern. If you subtractively mix the primary colours, you get a very dark brown (perfect primary colours would give you black).
Chookas;
Break-a-Leg Back
to top
"Chookas" is the Australian equivalent to "Break a Leg"
Superstition against wishing an actor Good Luck! has led to the adoption of this phrase in its place. Popular etymology derives the phrase from the 1865 assassination of Abraham Lincoln. John Wilkes Booth, the actor turned assassin, leapt to the stage of Ford's Theater after the murder, breaking his leg in the process. The logical connection with good luck is none too clear, but such is folklore.
There is no evidence, however, to suggest that this is the true derivation, and since the earliest usage of the phrase dates to the 1920s, there is much to suggest that it is not. The best that can be said is that the origin is unknown.
A DICTIONARY OF CATCH PHRASES (see below) suggests that there may be a connection with the German phrase Hals und Beinbruch, an invitation to break your neck and bones. The German phrase is used by aviators and is equivalent to the English phrase Happy Landings!. Both phrases arose about the same time, the early twentieth century, but the connection between the German aviation community and American theater is unclear, so they may be unrelated.
A DICTIONARY OF SLANG AND UNCONVENTIONAL ENGLISH, published some eight years before the above, does not list the theatrical meaning. Instead, it lists an obsolete meaning of "to give birth to a bastard child," from circa 1670.
Sources
A Dictionary of Catch Phrases; Eric Partridge; edited by Paul Beale; Scarborough House; 1992; ISBN 0-8128-8536-8. Contains excellent information, but unfortunately suffers from an odd alphabetization system, the lack of an index, and few cross references, all of which makes finding the phrase you want difficult at best.
A Dictionary of Slang and Unconventional English, 8th Edition; Eric Partridge; edited by Paul Beale; MacMillan; 1984; ISBN 0-02-594980-2. A superb source that focuses mainly on British slang, but which is also useful for Americanisms.
Cyclorama Back to top
From Greek Cyclos (circle) and Horama (view or vision).
Usually shortened to just "cyc" (pronounced
sike). The Cyclorama is a curved plain cloth or plastered wall filling the
rear of the stage or TV studio. Often used as a "sky" backing to
a traditional set, or as the main backing for a dance piece etc. The term is
often loosely applied to a blue skycloth, or any flattage at the rear of the
stage. Although strictly a cyc should be curved, most cycs are flat with curved
wraparound ends. A more effective backing can be obtained by hanging a sharkstooth
gauze just in front of the plain white cyc which gives a hazy effect of distance.
Lighting Designer Christopher Snape - Professional Theatre and Concert Lighting Design Sydney Australia. Full House Production Services Pty Limited - Theatre and Corporate Events.