Intr 351 1 intro to lighitng

INTR 351- LIGHTING DESIGN

•Annette Hladio•[email protected]

•610-449-4049

mailto:[email protected]

LIGHTING DESIGN- IntroductionThe Power and Purpose of Light

•Why study light?•Experience comes from vision, vision comes from light

•Light is an extremely efficient way of altering perception

•So that we can make lighting decisions throughout the design process (rather than lighting as one step at the end)

•Bad lighting can ruin perfectly good design

For every design decision, there is a lighting decision that will support it or work against it.

LIGHTING DESIGN- Introduction The Design Mentality

•Design process:•What are we lighting? •How are we going to light it?•How do we control it?

•“Brainstorm”•No wrong ideas, need to justify decisions•Write it all down

•Keep a record of ideas•Turn ideas into goals

•We are all creative•Get those ideas out of your head•Make room for more

We’ve all got ideas. Get them out of your head and onto paper. Make room for more ideas, refine the ones you’ve got and convert

them to goals that will become a reality

LIGHTING DESIGN- Introduction The Design Mentality

•The responsibility of the designer•Always be aware of your environment

•Dissect the world around you•Recognize that everything is designed

•Reverse engineering•Take something that works and figure out how it works

•Put this knowledge to work to create a predictable effect

•Reverse engineering from design•Step 1: Go into the world and experience design

•Step 2: Take stock of your emotional state

•Step 3: Identify what fixtures are being used and what they are lighting that causes that emotion or feeling.

Identify what is working in the designed environment. Put that feature to use to create the same effect in your own design

LIGHTING DESIGN- IntroductionLighting Terminology

•Before we go on: an Introduction to basic lighting terms• We quantify light as “lumens”

•“pieces” of light •Lumens of light striking a surface = Illuminance

•Expressed in Foot-candles•Lumens of light leaving a surface generically = Exitance

•Exitance is simply light leaving, with no indication of direction•Lumens of light leaving a surface in a specific direction in a specific density

•Luminance is light leaving in a specific density as viewed from a specific vantage point•Luminance is most closely related to the assessment of “brightness”

•These terms are all expressions of Lumens of light interacting in different ways

Basic light interactions are always about “Lumens” of light interacting indifferent ways.

LIGHTING DESIGN- IntroductionLighting Terminology

LIGHTING DESIGN- IntroductionThe Physics of Light

•Light is a member of a large family of phenomena called electromagnetic radiation (EMR)

•EMR is raw energy•Heat, light, x-rays, microwaves, U.V. are all examples of EMR (radiation)•EMR has no mass, no taste, no color•All EMR radiation travels at the same speed: “the speed of light”•700 million miles/ hour•EMR varies only in wavelength

•Wavelength is measured in Nano-meters

•We can symbolize EMR as tiny squiggly lines vibrating through space

LIGHTING DESIGN- IntroductionThe Physics of Light

•Our eyes can detect only a small portion of the spectrum: so we call this portion the “visible spectrum”

•Because we detect this EMR we name it. We call it light!•The visible spectrum includes radiation from about 380 Nano-meters (violet) to 770 nano-meters (red) in wavelength.•Light- visually evaluated radiant energy.

LIGHTING DESIGN- IntroductionFundamentals of Vision: The Eye

•The mechanisms we use•Accommodation (focus at different distances)•Adaptation (adjust for dark or bright situations)

•Diagram the human eye•Cornea: clear transmitting / refracting / protecting device•Iris / pupil: some of our dark/light adaptation (dilate)•Crystalline lens

•Flexible to change shape to refract differently to accommodate (focus)•Presbyopia: the hardening of the lens as eye ages•Test your near point (flexibility)•Aqueous humor , vitreous humor

•The retina: home to all of our photoreceptors (light detectors)

•Described as three parts: periphery (rods), macula & fovea (cones)•Can be permanently damaged

LIGHTING DESIGN- IntroductionFundamentals of Vision: The Eye

•Cones•Populate the macula and fovea•Active in high light levels (called Photopic vision)•Responsible for color vision (if you perceive color, you are using cones)

•Rods•Populate the periphery of the eye •Active in low light situations (called Scotopic vision)•Very sensitive to change and motion•Only come in one class (therefore Scotopic rod vision is monochromatic)

LIGHTING DESIGN- IntroductionFundamentals of Vision

•Perceived visual experience

•Dependent on:•color of light•surface reflectance•visual system

•Color Blindness

LIGHTING DESIGN- IntroductionFundamentals of Vision

•Visual Acuity- •How well can you see?

•Depends on:•Size•Contrast•Length of time

LIGHTING DESIGN- IntroductionColor Science

•Completeness of spectrum•The more wavelengths that come out of a light source, the more opportunity a surfaces has to reflect light•We call this the COLOR RENDERING INDEX or CRI

•It is a numeric value ranging from 0-100 (the higher the better)•Typical CRI

•Daylight: 100•Incandescent light: 100•Fluorescent: 75 - 95•Metal halide: 75-90•High pressure sodium: 25•Low pressure sodium: 25


•Color temperature•If a light source gives of more of one wavelength than another, than our brains translation of the light is a slight color difference.•We have devised a numeric description of the color produced by the imbalance called CORELATED COLOR TEMPERATURE (CCT)

•Expressed as a temperature in degrees Kelvin K or “Kelvins”•Extracted from the behavior of black metals as they are heated up: red to orange to yellow to blue etc.•We use it most to help describe fluorescent and HID sources.


• Color mixing


•Think about what light is responsible for•Lighting as mood

•Active vs. Relaxed•Intimate vs. clinical

•Lighting as instruction•Way finding•Directional clues

•For every lighting “mood” there is a corresponding light intensity, light color and light texture.

Lighting is one of the best “bang for your buck” design ingredients

LIGHTING DESIGN- IntroductionLess is More

•Good lighting design is simply a study of where light ends up.-What do you want to light!•4 relationships shape our understanding of where light is most effective.

• 1. Adaptation: Humans have the ability to adapt to function under vastly different light levels

•High-noon Sunlight is tens of thousands of times brighter than full-moonlight, yet we can read under both.•Excess light is wasted light as our visual system works to even out our experience.

• 2. Brightness: The subjective judgment of lighted objects in an environment.•Brightness is the product of contrast. Object are judged in relation to their surrounding.•“Bright” objects need only be brighter than their neighbors.

• 3. Phototropism: Humans notice bright things and ignore dark things•A few lighted objects can define the general feeling of a space (if they are in plain sight)

• 4. Vertical Vision: Humans tend to notice what is right in front of them.•Vertical surfaces (walls and objects) do more to define the impression of a space than the floor.

•All of this means that a few well placed pieces of light can define a space as “bright”•Lighting design becomes a study of contrast and placement rather than the application of even light levels throughout a space.

A small quantity of light in the right place is much more effective than any quantity of light in the wrong place.

LIGHTING DESIGN LECTURE 1Less is More

•Lighting can be applied in two distinct steps (page 26)

•1. Lighting Specific surfaces: tasks, accents, local visual effects•Imagine that we can “paint” light on to specific objects as if with a brush or spray can.•These few specific pieces of light will draw attention and create a perceived brightness.•Every piece of applied light will inter-reflect and contribute to the overall ambience.•Assess these effects, then…

•2. Augment the feeling of brightness•Apply light on to the vertical surfaces (and reflective surfaces) to increase the perceived brightness.

•Lighting specifics, then assessing, then augmenting brightness / ambience accomplishes the following:

• Minimizes the risk of wasting light. • Creates hierarchy and visual interest,• Leaves room for impacting lighting effects.• Reduces glare and eye strain

Light specifics first, then assess the effect. Then apply light to augment the ambient brightness.


•Think about the controllable aspects of light•Intensity of light: Bright vs. dark

Bright vs. Dark


•The controllable aspects of light•Color of light: Cool vs. Warm (and saturated colors)

Cool vs. Warm


•The controllable aspects of light•Texture of Light: Diffuse vs. Directional

Diffuse vs. Directional

LIGHTING DESIGN- Introduction The Power and Purpose of Light

•Behavioral response to light•Light differs from other design elements, because our response is instinctual versus learned or conditioned

•This Instinct is called “phototropism”, meaning “light responding”

•If we control light, we control:•How people feel

•How people perceive a space

•Where people go

•We want to understand and master every tool available to us to elicit the desired response in our designed environments

Instinct and attraction make light a very powerful tool

LIGHTING DESIGN- IntroductionLess is More

• Visual Contrast • We can not light air, we need to light objects.• We discern detail by how bright an object is related to the background.• 2:1 brightness ratio is minimal.• 4:1 creates more of a focal point.

LIGHTING DESIGN- IntroductionFor Next Week

•Next week: •Lighting Fixtures

Intr 351 1 intro to lighitng

Design

Transcript of Intr 351 1 intro to lighitng