Sophomore Architecture Studio: Lightingcharacteristics of a light source. They show the radiant power emitted by the source at each ... – Developed the incandescent carbon filament

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Sophomore Architecture Lighting Lecture 2: Optics and Controlling LightSpring 2010

Sophomore Architecture Studio: Lighting

Lecture 1:• Review of Daylight• Introduction of Electric Light• Survey the Color Spectrum• Summary of Light Sources

Lecture 2:• Controlling Light• Effects on Materials

Lecture 3:• Light in Architecture• Lighting Design Strategies

Light Sources

Generators –Transmitters

Secondary Light Sources

Modifiers and Re-transmitters

Eyes

Receivers –Encoders

Brain

Decoder –Interpreter

Sun, Discharge lamps, fluorescent lamps.

Incandescent lamps, Open flames, etc.

Atmosphere, Air, Water, Planets, Lenses, Windows, Tress – All natural or manufactured objects which modify light waves before they

reach the eye.

Cornea, Iris, Lens, Rods & Cones, Optic Nerves

Analysis, Identification Association Perception

Controlling Light Light = Color

Light = Color Light = Color

Colors by AdditionMixture of Light

Colors by SubtractionMixture of Pigments

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Light = Color

Daylight at Noon Afternoon Sun

Candle

Full Moon

Incandescent CompactFluorescent

TubularFluorescent

Light = Color

Metal Halide High Pressure Sodium

PC Laptop

PC Monitor(indigo nightlight)

Light = Color

Spectral Power Distribution Curves (SPD) provide the user with a visual profile of the color characteristics of a light source. They show the radiant power emitted by the source at each wavelength or band of wavelengths over the visible region (380 to 760 nm).

Color Spectrum

Incandescent Lamps and Natural Daylight produce smooth, continuous spectra.

Night Morning Afternoon Late Afternoon Night

Color Spectrum

Fluorescent Lamps produce a combined spectrum… a non-continuous or broad spectra with gaps from their phosphor, plus UV from the mercury discharge.

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http://www.gelighting.com/na/business_lighting/education_resources/learn_about_light/color_lamp.htm

Seeing Color

The higher the color temperature (CCT), the “cooler” the color of the lamp is in appearance.

2700 o 4100 o2200 o

The lower the color temperature (CCT) the “warmer” the color the lamp is in appearance.

This color temperature is measured in Kelvin.

Correlated Color Temperaturecolor appearance of various light sources

Correlated Color Temperaturecolor appearance of various light sources

5000 deg Kelvin 4000 deg Kelvin 3000 deg Kelvin

9000850080007500700065006000550050004500400035003000250020001500

Kelvin TemperatureCool

Warm

North Blue Sky

Direct Sunlight

Overcast Day

Fire / Candle light

Hot Embers

HalogenIncandescent

Mercury

High Pressure Sodium

Metal Halide

3000K Metal Halide

Daylight FluorescentCool White Fluorescent

4100K Fluorescent

3500K Fluourescent3000K Fluorescent

Warm White Fluorescent

Correlated Color Temperature

Color Rendering Index: The color rendering of a light source is an indicator for its ability of realistically reproduce the color of an object.

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Light Technologies

New Developments

There was a need to improve the light several ways:1. The need for a constant flame, which could me left unattended for a longer period of

time2. Decrease heat (and smoke) for interior use3. To increase the light output4. An easier way to replenish the source….thus, the development of gas and electricity5. Produce light with little waste or conserve energy

Early Electric Light Technologies

arc lamps early in the 19th century

Early Electric Light Technologies Early Electric Light TechnologiesEdison and Swan:

– Developed the incandescent carbon filament lamp in late 1870s

– Edison designed a complete electrical system and a lamp that could be mass-produced

Light Fixture

Electric Sources

LampBulb

Electric Sources

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Wiring Basics Basic Wiring

Lamps Electric SourcesLamps for General use

INCANDESCENTLAMPS (filament)

DISCHARGELAMPS

Incandescent

Halogen

FluorescentLinear

Compact

High Intensity (HID)

Electric SourcesLamps for General use

PointsBlobsLines

Lamps = Sources

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Points How Incandescent Lamps Work

How Halogen Lamps Work

Halogen Cycle

Points: General Purpose/ A-Lamps

Points: Decorative Points: Specialty / T and S - Lamps

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Points: Halogen Lamps

• Light-emitting diodes (LEDs): – Semi-conductor devices that have a chemical chip embedded in a

plastic capsule

Points: LED’s (sometime act as blobs)

How LED’s Work

When the negative end of the circuit is hooked up to the N-type layer and the positive end is hooked up to P-type

layer, electrons and holes start moving and the depletion zone disappears.

When the positive end of the circuit is hooked up to the N-type layer and the

negative end is hooked up to the P-type layer, free electrons collect on one end of the diode and holes collect on the other.

The depletion zone gets bigger.

The interaction between electrons and holes in this setup has an interesting side effect -- it generates light!

How LED’s Work

How LED’s Work Points: LED’s

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Points: LED’s LED

http://www.colorkinetics.com/showcase/videos/target.htm

http://www.colorkinetics.com/showcase/videos/wlf_04.htm

LED

http://www.lif-germany.de/film/mov07793.mpg

Blobs

“Blob” Source Halogen Lamps

ReflectionRays are Parallel

Parabola or Parabolic Reflector

Typically Specular Finish

Rays converge

2 fociEllipse, Ellipsoidal, or Elliptical Reflector

Typically Specular Finish

“Blob” Source Halogen Lamps

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Blobs Points arranged in a Line

Lines Lines: Fluorescent

How Fluorescent Lamps Work Fluorescent Lamp Design..the old way

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Fluorescent Lamp Design

Rapid start and starter switch fluorescent bulbs have two pins that slide against two contact points in an electrical circuit.

“Change a bulb and save the world!”

Fluorescent Systems

Pin Based Fluorescents (remote ballast):

Tubular T5, T8, T12Double, Triple, Hex, BIAX

• Ballast Options: Power Factor– High Power Factor = > 0.9– Normal Power Factor = 0.4 – 0.6

• Ballast Options: Dimmable– 1% to 100%– 5% to 100%– 10% to 100%– Multi-level

• Lamp Life = 10,000 hours• Ballast Life = 100,000 plus hours

Screw Fluorescents (integral ballast):

Medium base Compact FluorescentCandelabra base Compact

Fluorescent

• Ballast Options: Power Factor– Normal Power Factor = 0.4

• Ballast Options: Dimmable– Range Not Known

• Life = 5,000

Incandescent lamps are a simple thing. A bit of wire that gets very hot. It presents a very simple, resistive load to the electricity supply.

Fluorescents on the other hand is much more complex. The electronics required to make these lamps work present what is known as a reactive load. A ballast is required to operate the source, but the power required to operate the ballast may not be efficient.

• Poor spectrum, poor color, poor rendering (CRI = 90-40)

• Screw base difficult to dim (“dims to greenish brown color…”), pin base requires special ballast and control

• Long Life (limited to 3-hour on cycle)

• High efficacy rating (lumen/watt)

• Cannot replace point source bulbs in point-source fixtures, Cannot replace all 1000+ incandescent bulb types

• Contains toxic mercury (if incandescent is banned, 50,000 lbs of mercury will be introduced into landfills upon disposal every 7 to 10 years)

• High embodied energy (several times that of incandescent), most are made in China, which uses coal fired methyl mercury producing power plants

• Customer Dissatisfaction: limit uses, high initial cost; high failure rate (many fail after 2 to 20 hours)

Lamp Pros and Cons

• Excellent color, reliable, highest color rendering (CRI = 100)

• Dims easily without specialized equipment.

• Dimming extends life and energy consumption.

• Halogen vs incandescent are 30% more efficient, approach CFL efficiency with controls and beat fluorescents in many categories.

• Do not have negative disposal impacts, fully recyclable

• More efficient to produce, i.e., less embodied energy

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What is inside the lamp

1. glass 2. steel 3. a small amount of high temperature plastic insulation4. (lead free?) solder 5. plating material for exposed metal, probably nickel

6. tungsten 7. inert (and naturally occurring) gas

1. glass 2. steel 3. a small amount of high temperature plastic insulation 4. (lead free?) solder 5. plating material for exposed metal, probably nickel

6. phosphors ** 7. mercury + mercury vapor ** 8. silicon (in ICs, transistors, MOSFETs, diodes, etc.)9. fiberglass and epoxy resins (PCB, semiconductor

cases)10. aluminum (electrolytic capacitor)11. various plastics (main housing, film capacitors)12. ferrites / ceramics (resistor bodies, choke cores) 13. copper wire and PCB traces

** are either toxic, or may be toxic when mixed with other chemicals in landfill.

Screw it Where?

Most screw base CFL packaging states that the lamps must not be used in fully enclosed light fittings. The reason is temperature. Because of the electronic circuitry, all CFLs can only be used where they have reasonable ventilation to prevent overheating. (Excess heat doesn't bother an incandescent lamp, and temperatures well in excess of 100°C won't cause them any problems at all. )

$2,000 Clean-Up Bill

Many people would have seen the story circulating the Net about a woman in Maine (US) who broke a CFL in her daughter's bedroom, and was quoted $2,000 to clean up the mercury.

Yes, mercury is a potent neurotoxin, but metallic mercury is relatively safe. The real danger comes from the vapor and various salts andcompounds (as may easily be created in landfill for example) ... not from 5mg of mercury buried in the carpet.

How Florescent Lamps are Recycled Cold Cathode

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Neon

ten digits of a Z560M Nixie Tube.

Light Direction

Light travels in a straight line…radiates out from the source

Light Direction of Small or Clear Sources


…. add a clear enclosure or envelope around the source, the light will still travel in a straight line.

Light Reflects

• Luminaires can shape light by reflection

• Reflectors finishes may be – Specular – shiny, polished

– Semi-Specular

– Diffuse – dull, matte

Light Source

Light Reflects

• Luminaires can shape light by reflection

• Reflectors may be – Specular – shiny, polished

– Semi-Specular

– Diffuse – dull, matte

Light Source

Light Reflects

• For “specular” reflectors, the angle of incidence equals the angle of reflection

Light Source

Incidence

Reflection = the light that exitsIncidence = the light that enters

Reflectance

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Light Reflects

• Optics– Absorption

– ReflectionLight

100%

80% 80%

Example: The material absorbs 20% - reflects

80%

Typical Materials:MetalMirrorWood

Projections

Light Direction of Large or Frosted Sources


…. add a coated or frosted enclosure or envelope around the source, the direction of light will bend and radiate from the surface of the enclosure

Light Transmits

• Optics– Absorption

– TransmissionLight

100%

80% 80%

Example: The material absorbs 20% - transmits

80%

Typical Materials:GlassPlasticFabric

Light Bends

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Lighting Design is Shade and Shadow

Light and shadow belong together.

Yet the increasing number of artificial light sources on earth are resulting in continuously decreasing zones of shadow and darkness.

In architecture, the growing use of glass and other translucent layers questions the very significance of shadows.

Do they protect against or cause a loss of brightness?

Do we even need shadows today at all?

Shadows are full of Secrets

The table cast a shadow on the grass.

Why do we say the table cast a shadow on the grass, and not the grass cast a shadow on the table?

Shadows are full of Secrets

A shadow is the absence of light.

…a negative entity, an absence, a hole in the light, there is nothing within the shadow to give it direction.

Shadow Terminology

Shading

Attached Shadow

Inter-reflection

Cast Shadow

Penumbra

Shadow Terminology

Highlight

Refracted Shadow

Refracted Light

Cast Shadow

Penumbra

Shadow Terminology

Shading

Shading

Highlight

Diffuse

Glossy

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Penumbra

Small light source

Full Light

100%

0%

No light

penunbra

Penumbra

Large light source

Full Light

100%

0%

No light

penunbra

Shade and Shadow

Shade

Shadow

Shadows in Science

Shadows Teach Us Shadows Teach Us

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Shadow Recognition (identification)

We see a shadow, then activate a recognition process that triggers the category of the object

Shadow Recognition (identification)

We see a shadow, then activate a recognition process that triggers the category of the object

Shadows Proofs

Typically shadows hide. But, a shadows can also reveal. In this case, the round shadow cast from some object out of view can sharpen the contrast of the small shadow , and make it more visible.

Losing Shadows

The image of a face is seen on the left – shadows reveal the contour,But, outline the shadow, and the effect is lost.

The outlining turns the shadow into a non-shadow, and prevents vision from using it to reconstruct the 3-D structure of object.

Famous Shadows Famous Shadows

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Famous Shadows Famous Shadows

For light lends a building its contour….

..and shadow lends it depth.

Light And Shade:

Highlights and shadows can provide information about an object's dimensions and depth.

Our visual system assumes the light comes from above, a totally different perception is obtained if the image is viewed upside down.

Are these shapes convex or concave?

The direction of light provides visual information about an objects shape

Basic Concepts for Illumination of 3d Objects

Light from multiple directions..

• models a sculpture• expresses depth by highlighting some areas while

allowing others to fall into shadow• different angles render material variations with lesser

or greater emphasis

Irrespective of size, a three-dimensional artifact must be illuminated from several different directions.

Key light only Fill light only Back light only

Combination Key, Fill, and Back light

Shadows

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Kumi Yamashita Fabrizio Corneli

Larry Kagan Photographs

Using warm and cool sources for Key and Fill light not only increases sense of shape and depth of an object, but assist with defining direction of light


Using warm and cool sources for Key and Fill light not only increases sense of shape and depth of an object, but assist with defining direction of light

Cool Light And Warm Shade:

Color also can provide information about an object's dimensions and depth.

Our visual system assumes the light comes from above, we rely on our visual experience with nature to explain direction of light

“visual experience tells us warm light comes from the interior illumination, a cooler light source comes from nature – daylight at day, moonlight at night”


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Alexander Hamilton US Customs House, NYC Projections

Light in Art Light in Art

Rufus Knightwebb Dan Flavin

Light sculptures that illuminate space around them. They inhabit space. They bathe space - and visitors - in a warm and completely artificial glow

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Dan Flavin Dan Flavin



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Robert Irwin

Light create sensations, a transformative of experience of wordless thought. Neither object nor image, the works give form to perception.

Jason Bruges

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Jason Bruges Esa Laurema

James Turrel James Turrell

James Turrell James Turrell

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James Turrell "Skeet" James Turrell


James Turrell http://www.youtube.com/watch?v=gjRMs0izHSE James Turrell "Wide Out"

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James Turrell

Light Works that amplify perception, give form. Each installation activates a heightened sensory awareness that promotes discovery

James Turrell http://www.youtube.com/watch?v=2m08kGQEBZ4 James Turrell “Out of Corner”

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James Turrell “Out of Corner” James Turrell “Out of Corner”

James Turrell “Out of Corner” James Turrell “Out of Corner”

James Turrell “Out of Corner” James Turrell

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James Turrell “Wedgework” James Turrell “Wedgework”

James Turrell Peter Freeman

Fiber-optic light points change color and sparkle, creating glittering colored surfaces. The mass of the sculpture is made from white sprayed concrete.

Peter Freeman Peter FreemanLight interventions work closely with the architecture to create an installation that expresses the spirit, function and the form of the building.

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Peter Freeman

Artificial light compliments the daylight creating a sense of wonder, excitement and security for the night landscape of the built environment.

Light and water are essential to life. Where they mix and interact they create beautiful colors and reflections

Paul Friedlander

A space where technology meets creativity in an environment designed to appeal to a style

Paul Friedlander Paul Friedlander

Works that are three-dimensional moving light projections. Practice of kinetic art is the development of new media and techniques

Paul Friedlander Jorge Pardo

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Dan Graham

Theme of the transparency/reflection duality, the scattering of the boundary between observer and observed

Dan Graham

Ingo Mauer

Transforming with light objects and images to emotions, joy and fun

Ingo Mauer

Ingo Mauer Targetti Light Art Collection

http://www.targetti.it/art/en/section_1/Light_Art_Collection

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• Daylighting Models

Building a Model

Tip 1

Do not use Foam Core – the material glows and creates light leaks

Use black paper on white board and cover or tape all light leaks

Black Foam Core is expensive.

Tip 2

White Foam Core is reflective and shiny.

Cover the insides with appropriate surface reflectance or color material.

Tip 3

Make a modular model with interchangeable parts.

Tip 4

Mirrors can enhance the depth of a model.

Mirrors are useful in large space with respective plans.

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Tip 5

Know true north and latitude.

Draw north arrow on your model.

Tip 6

Include accessible large view ports.

Large enough for use cameras or yield a good view of the interior.

Tip 7

Include people or objects for scale.

Documents

Sophomore Architecture Studio: Lightingcharacteristics of a light source. They show the radiant power emitted by the source at each ... – Developed the incandescent carbon filament