Everyone today wants to be a lighting programmer or designer
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Light Emitting Diodes also known as LED has taken over the live entertainment industry. in this course we will discuss basic conventional lighting; the incandescent lights and LED.
Basic Conventional Lighting 101: Incandescent
1) Ellipsoidal Reflector Spotlight (ERS)
2) Fresnel
3) Source Four PAR and the Source Four PARnel
4) Cyc light - is used to light up drapery preferably a large wide drape, by lighting it can mimic a sky, creating time of day effect. Used on stages and studios.
LED lighting: Most of these lights use conventional dimmers or DMX control protocols
powerCon connectors, and the rest is still the same.
1) LED Ellipsoidal high-power, versatile stage lighting profile - at Valencia we use one of the following ETC Source Four LED
More Info: https://www.etcconnect.com/Products/Lighting-Fixtures/Source-Four-LEDs/Features.aspx
2) LED Fresnel wash light - at Valencia we use one of the following Ovation FD-165WW Chauvet Fresnel wash
More Info: https://www.chauvetprofessional.com/products/ovation-fd-165ww/
3) LED Cyc Chroma-Q Color Force 48" or 72" RGB light
More Info: http://www.highoutput.com/gear/chroma-q-color-force-48-72-led/
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1) Edison connector (some of these connectors a common to not have a ground wire included)
2) Twist Loc connector (various sizes L5, L6 etc)
3) Stage Pin connector (one main size, other sizes for film and or studio production)
* Note: all connectors have a male and female end.
(Photos below are from the ETC website unless if the photo image itself states otherwise. http://www.etcconnect.com/products.fixtures.aspx)
Ellipsoidal Reflector Spotlight - ERS
Most common lighting fixture used for the stage as it provides a variety of functions and capabilities.
Available in Tungsten Halogen and LED w/engine.
The brand of this light is Electronic Theatre Controls (ETC), other brands are Strand Lighting, Colortran and Altman's are an older version of lighting instruments.
The wattage for the ETC brand ERS ranges from 575 watts to 750w per lamp.
The ERS has the following: (by Sonia Pasqual)
KEY NOTE: The Ellipsoidal Reflector Spotlight (ERS) has an ellipse mirrored/glass reflector located in the back section of the instrument. Hence why this instrument is called an ERS! This instrument has a very well known nickname called the LEKO, in this introduction to stage lighting class we will only refer to it as the ERS so you get in to your head, why, because calling it by the nickname :)
1) 4 SHUTTERS -made of steel used to cut out light from an object where it is not desirable.
2) PLANO CONVEX LENS - in the barrel of the instrument that allows for soft edge to hard edge focus.
3) BARREL front part of the light houses the lens at a certain degree or focal length of that particular instrument, for example the lens vary in position in the barrel to get different focal lengths. This is useful as the same light can be used at different distances in a venue, to cover more of an object with light, or less light, depends on project.
4) BARREL KNOB - is located on the barrel itself, if loosen just a little bit, allows the barrel to slide back and forth for focusing.
5) GEL FRAME SLOT - located to the front section of the barrel, is an opening that allows a gel or filter to be placed in a gel frame holder. This allows the ability to change the hue or saturation of the lights color output.
6) GEL CLIP - located at the top of the barrel where the gel frame slot is so once the gel frame has a gel in it, it can be place in upright (open side on top) and the this clip slides over and down to secure the gel frame into place.
7) ROTATION KNOB - is another small knob behind the barrel located on the back body of the instrument. This knob if loosen just a little bit, allows the front section of the light (shutter to barrel section) to rotate 180 degrees. This allows for an adjustment for the shutters and or is the instrument has a template pattern (gobo) in place and need be tweak in its pattern.
8) LAMP BASE - (sometimes called the Burner Base) is located at the chimney or back of the instrument. The lamp base is what we will refer to it in this class, houses the lamp itself and also the lamp focus knob on its exterior - a black knob. There is a brass screw also located there to detach the lamp base from the instrument itself, handy to replace a blown lamp or bad base.
9) YOKE - is the metal brace which is attached to the instrument and it allows it to be attached by the C-clamp to the batten or electric.
10) YOKE KNOB - is usually located at the right side of the instrument if you are standing behind the light. It can vary, it however the knob (small handle) if loosen can allow the light to be tilted up or down for extended purpose of focusing the light.
11) C-Clamp is attached by a bolt to the yoke (the yoke bolt). The C-clamp is the actually the part which attaches the instrument to the batten and or electric for hanging purposes. The C-clamp has another locking bolt, at an angel to the c-clamp and batten allowing the instrument to be locked into place using an adjustable crescent wrench.
12) PAN SCREW - some c-clamps have a pan screw, it is a small screw head on the side of the c-clamp if loosen a little bit will allow the instrument to pan left and right.
13) YOKE BOLT - all instruments have this and it is the main way to pan the instrument left and right for focusing purposes. This will be loosen by the use of the adjustable crescent wrench a little bit until you can turn it by the yoke towards the desired focus placement. Then tighten down so it does not move and stay in place.
Parabolic Aluminized Reflector - PAR can
Now obsolete. LED PAR Cans are the way to go!
A great light for casting a harsh beam of light, it may be used depending on the type of lamp for a flood wash of light to an area.
Lamps for this instrument are as follows:
a) Very Narrow Spot Lamp - VNSP
b) Narrow Spot Lamp - NSP
c) Medium Flood Lamp - MFL
d) Wide Flood Lamp - WFL
By looking at the lamp you can tell which lamp it is. The VNSP and NSP has a clear or frosted glass. The MFL has 8 rows down of what I call the honey combs and the WFL has 12 rows down of the honey combs.
This stage instrument is mainly used in concert lighting (VNSP or NSP as an effect), as you can get varied beams from the light source output. The PAR can comes in various sizes of the instrument and (lamps: MR-11, MR-16, 38, 46, 56, 64) and is related to the flood lights that is used in gardens (R40 lamps) and or recessed lighting that are in the homes.
The COMMONLY USED STAGE PAR CAN is the 56 or 64. The lamp wattage for both of these instruments vary from 500 watts to 1000w.
The main parts of the Parabolic Aluminzed Reflector - PAR are as follows:
1) The Aluminum CAN Body.
2) GEL SLOT
3) YOKE with yoke bolt attached to C-clamp (Pan focus)
4) YOKE KNOB (Tilt focus)
5) Open Back (focus of the lamp)
6) Retaining clip to hold the lamp in place.
7) Ceramic base, connected to the Mogul End Prong lamp base. It can be turned 360 degree to alter the focus of the oval beam.
Fresnel
Now available in LED.
Chauvet Professional carries a selection of LED, color mixing RGB fixtures.
https://chauvettheatre.com/fresnels/
This stage lighting fixture is popular for its step lens. The name Fresnel comes from the inventor of its lens Augustin-Jean Fresnel (1788-1827). The instrument is very simple in its construction and contains a spherical reflector, a lamp, and a Fresnel lens or step lens. The brand of this fixture is Colortran.
The size of this lighting instruments begins at three inches to twelve inches.
This type of light is used to flood and area with the light source, the output of the light is soft especially if it used in conjuction with a diffusion gel filter or is used to reflect off a surface (fabric or reflective mirrored paper) which then is directed towards the object to be lit. You will see this light, in a larger scale two feet for TV studios and Film.
Source Four PAR
This modern stage lighting fixture is another great essential. It combines the lamp of an ERS and the functionability of a PAR can but with much more improvement. This fixture has 4 lens that are changable (and 5th one new '07) the brand of this light is ETC.
Source Four PARnel
This modern stage lighting fixture is great for casting a soft and even wash of light. It has a lens which provides the capability for softness as the light is transmitted through it. It functions using an ERS type of lamp, and has the identical body of the source four par, so you can only tell the difference between the two fixtures by looking at the lens or if still in tact reading the label information on the yoke of the light. The brand of this light is ETC.
Overview Information: Electricity for the Stage: This is not something to play with!
Stage lighting deals with three components of electricity that the National Electrical Code has broken down as the following catagories: 1) Voltage 2) Amperes and 3) Wattage
1) Voltage (Volts = V = E for energy) is the -Electromotive force {EMF} behind the free electrons or electricity which is created that then moves the electrons producing electricity throughout that circuit.
EXAMPLES of voltage its electromotive force can be supplied through:
- *Battery voltage flows through a wire (copper is great) in one direction creating what is called direct current or (DC).
- *Electrostatics created by friction or rubbing two dissimilar substances together.
- *Generators work by moving a conductor within a magnetic field around two magnetic poles in the armature. The movement of either the field or the conductor creates an ongoing flucuating charge in the magnetic field allowing electricity to flow consistently. This then creates a simplified alternating current (AC) usually called an alternator, the generator supplies power that is recharged.
- *Sunlight, heat, compression, certain substances and generators all supply electromotive force/voltage.
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2) Amperes (Amps = A = I for intensity) is the amount of electrical current that is flowing in a conductor. consistently.
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3) Wattage (Watts = W = P for power) is the amount of power or driving force that is performed by the combination of the wattage and voltage available in the overall circuit.
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An electrical CIRCUIT is consisted of voltage, amperage, wattage and ohms. A circuit has a set limit of wattage available it is set by the NEC and or the manufacturer of its power outpul capability. A circuit allows for the power within it to be used through a connection which is made by the means of a plug. A circuit in stage lighting is also reffered to as a dimmer.
The standard voltage in the United States has an electrical output (voltage = volts = V = E) varying from the power substation through the transformers and into the main building power where it then spread throughout particular rooms and floors etc ranging from 110 volts to 120 volts.
110 volts is the minimum of any given wall circuit and it fluctuates to a maximum of 120 volts.
Types of Cables
Cable types provides an electrical plug or connection to a circuit. Since a circuit contains an electrical charge which can be dangerous if handled improperly or in case of an accident. The cable types that has been developed are manufactured to handle more types of environments that those of us in entertainment experience on a production. This labelling means that the cable itself is insultated to tolerate a certain level of these conditions. Below I have provided some of the cable types which I have worked with or seen.
Cable labelled:
SO = Solids and Oils
SJ = Solids and Chemical Substances
SJO = Solids, Chemical Substances, Oils
SOW = Soilds, Oils and Water
SJOW = Solids, Chemical Substances, Oils, and Water
Cable Ampacities
Cable Ampacities
Gauge Amperage
18 03
14 15
*12 20
10 25
The higher the gauge of the cable the lower the amperage that can be used.
THINKING WISELY: So think about this, you need 10 cables at a gauge of 12gauge - 20amps but the vendor only has 5. The vendor sales person says, "I do have 10gauge - 25amps cables that you can use, its a little more costly, do you want those?" Yes, why because if you are wanting 12gauge -20amps and really need to put up your show, the 10g -25amps has more than enough to handle the gear and equipment you need it for. So if you budget provides the funds to spend it and get the show going, go for it.
The Power Formula: What! There's math involved? YES.
The WEST VIRGINA FORMULA:
The power formula is referred to as the West Virginia Formula. It states the rate of the wattage is equal to the product of current flow (amperage) and the voltage.
Watts = Volts x Amps using the first letters of the names is how the name West Virginia.
or Power = Intensity x Energy
For example: if you have a lamp that is 750w and your wall outlet is 120v, the amps of the outlet is 20amps, how many 750w lights can you have circuited to that one wall outlet?
W = 750 V = 120 A = 20
1) W = V x A or P = I x E 2) 750 = 120 x 20 3) 750 = 2400
4) 750/2400 = 3.2 = to 3 (750w lights can be plugged into a wall outlet that has 120v and 20a)
Try this one: You have 1000w light, how many lights can you plug into a wall outlet that has 115v and 20a?
ANSWER:
115v x 20a = 2300w divided by 1000w = 2.3 lights equals = 2 lights
(photo above credited to : http://www.onstagelighting.co.uk/wp-content/uploads/images/stage-lighting-rig-shadows.jpg )
Lighting: Reflection, Reflectors and Refraction
Specular Reflection
Reflection combines mirrors and a light source that is then reflected off the surface of that medium or mirror design quality. Reflection of light using the specular reflection (that is, mirror-like) or diffuse (that is, not retaining the image, only the energy) depending on the nature of the surface. Specular reflection at a curved surface forms an image which may be magnified or demagnified; curved mirrors have optical power. Such mirrors may have surfaces that are spherical or parabolic.
1. Specular Reflection - changes the direction of a beam of light without altering the nature of beam. A mirror is a specular reflector. Take a look at the lighting in the classroom as it uses a reflective mirrored surface to reflected more light into the entire space of the room.
If the reflecting surface is very smooth, the reflection of light that occurs is called specular or regular reflection. The laws of reflection are as follows:
The incident ray, the reflected ray and the normal to the reflection surface at the point of the incidence lie in the same plane. The angle which the incident ray makes with the normal is equal to the angle which the reflected ray makes to the same normal. http://en.wikipedia.org/wiki/Reflection_(physics)
Diffuse Reflection
2. Diffuse Reflection - occurs when the beam of light is completely dispersed. The light bounces off the reflector in all directions.
When light strikes a rough or cotton fabrics, it bounces off in all directions due to the microscopic irregularities of the interface. Thus, an 'image' is not formed and light is reflected in no single direction. This is called diffuse reflection. The exact form of the reflection depends on the structure of the surface. http://en.wikipedia.org/wiki/Reflection_(physics)
Mixed Reflection
4. Mixed Reflection - is a mixture of diffuse and specular reflections. The rough surface of a cermaic surface creates diffusion while the shiny glaze acts like a mirror. Therefore, creating an object that bounces light outward that is both diffused and specular.
Examples: water, shiny surfaces, mirrors and glossy textures.
3 Types of Reflectors: Ellipsoidal, Spherical and Parabolic
Ellipsoidal Reflector
Stage lighting fixtures use several types of reflectors. By redirecting light coming out of the back of a lamp, a reflector increases the amount of usable light from any source. the shape of a reflector determines the manner in which the light is redirected. Every reflector has a specific point where a light source must be place in order to achieve the desired reflective pattern.
This location is called the reflectors focal point.
These are the most common reflectors:
1. ELLIPSOIDAL REFLECTOR - an ellipse (ellipsoid) curved shaped reflector, an ellipsoidal reflector is more efficient than either spherical or parabolic reflectors. The focal point nearest to the refelctor and where the source is place is called the primary focal point. The more distant focal point is called the conjugate focal point (secondary focal point). When a light source is properly positioned at that primary focal point, the rays striking the reflector are redirected to converge through the conjugated focal point (secondary focal point). This point of light source uses the reflector and a large percentage of the light is gathered into a concentrated beam. This is the reason why the ERS is a perfect source for hard edges and used as a spotlight.
Spherical Reflector
2. Spherical reflectors reflect all beams which strike the reflector from or through the center of curvature back through the center of curvature. This is indicated by the red lines and arrows in the drawing below. The focal point is at 1/2 the radius of the sphere. As with parabolic reflectors (see the section below), any beam that passes through the focal point and strikes the mirror will be reflected out in parallel rays. This is indicated by the amber lines and arrows in the drawing below.
Parabolic Reflector
3. Parabolic Reflectors - reflects all beams which strike the reflector from or through the focal point then out in parallel lines to each other in a beam of light approximately the diameter of the reflector. Example: searchlights, many hand-held flashlights/torches.
Refraction of Light = Bending of Light
Refraction refers to the bending of light. This can be observed by looking into a pool of water and noticing how a straight stick seems to bend sharply as it passes beneath the surface. Another observation can be when the sunlight hits the water and creates a breakup of reflection of the sun beams of light that is refracted in the pools surfaces itself.
The law of refraction states that when a ray of light passes into a denser medium such as glass it is bent towards a perpendicular drawn to the surface at the point of entry. (Disturbution control lighting: Scene Design and Stage Lighting by W. Oren Parker)
Photo below: An image of the Golden Gate Bridge is refracted and bent by many differing three dimensional pools of water. http://en.wikipedia.org/wiki/Refraction