This document provides an introduction to lighting design concepts. It discusses why lighting is an important design element and how light impacts perception. It introduces key terminology like lumens, illuminance, and luminance used to describe light. It also covers the physics of light, how the eye works, and factors that influence vision. Color science concepts like color rendering index and correlated color temperature are defined. The document emphasizes that lighting design is about controlling the intensity, color, and texture of light to elicit specific behavioral and emotional responses from people in designed environments. A few well-placed lights can be more effective than applying even light levels throughout a space.

1. INTR 351- LIGHTING DESIGN
•Annette Hladio
•Annette@archltg.com
•610-449-4049

2. LIGHTING DESIGN- Introduction
The 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.

3. 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

4. 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

5. LIGHTING DESIGN- Introduction
Lighting 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.

6. LIGHTING DESIGN- Introduction
Lighting Terminology

7. LIGHTING DESIGN- Introduction
The 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

8. LIGHTING DESIGN- Introduction
The 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.

9. LIGHTING DESIGN- Introduction
Fundamentals 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

10. LIGHTING DESIGN- Introduction
Fundamentals 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)

11. LIGHTING DESIGN- Introduction
Fundamentals of Vision
•Perceived visual experience
•Dependent on:
•color of light
•surface reflectance
•visual system
•Color Blindness

12. LIGHTING DESIGN- Introduction
Fundamentals of Vision
•Visual Acuity-
•How well can you see?
•Depends on:
•Size
•Contrast
•Length of time

13. LIGHTING DESIGN- Introduction
Color 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

14. LIGHTING DESIGN- Introduction
Color Science
•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.

15. LIGHTING DESIGN- Introduction
Color Science
• Color mixing

16. LIGHTING DESIGN- Introduction
The Power and Purpose of Light
•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

17. LIGHTING DESIGN- Introduction
Less 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.

18. LIGHTING DESIGN LECTURE 1
Less 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.

19. LIGHTING DESIGN- Introduction
The Power and Purpose of Light
•Think about the controllable aspects of light
•Intensity of light: Bright vs. dark
Bright vs. Dark

20. LIGHTING DESIGN- Introduction
The Power and Purpose of Light
•The controllable aspects of light
•Color of light: Cool vs. Warm (and saturated colors)
Cool vs. Warm

21. LIGHTING DESIGN- Introduction
The Power and Purpose of Light
•The controllable aspects of light
•Texture of Light: Diffuse vs. Directional
Diffuse vs. Directional

22. 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

23. LIGHTING DESIGN- Introduction
Less 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.

24. LIGHTING DESIGN- Introduction
For Next Week
•Next week:
•Lighting Fixtures