Chapter 5: Brightness

Question 1

The intensity of light falling on a given region of the retina at a certain time is a result of?

Answer 1

Brightness

Question 2

The intensity of light that the retina has been subject to in the recent past is a result of?

Answer 2

Brightness

Question 3

The intensities of light falling on other regions of the retina is a result of?

Answer 3

Brightness

Question 4

We quantify light as?

Answer 4

Lumens

Question 5

Lumens of light striking a surface will cause?

Answer 5

Illuminance

Question 6

Illuminance is expressed in?

Answer 6

Foot-candles

Question 7

Light that is reflected from a surface ina given direction back toward the eyes is defined as?

Answer 7

Luminance

Question 8

Lumens of light leaving a surface generally = ___

Answer 8

Exitance

Question 9

____ is light leaving

Answer 9

Exitance

Question 10

Exitance is measured in?

Answer 10

lm/ft^2

Question 11

Luminance is most closely related to the assessment of “____”

Answer 11

Brightness

Question 12

How is luminance measured?

Answer 12

cd/ft^2

Question 13

we talk about illuminance “___” a surface

Answer 13

Onto

Question 14

we talk about the exitance “__” or “___” a surface

Answer 14

of; from

Question 15

we talk about the luminance “_” or “__” a surface

Answer 15

of; from

Question 16

____ is light leaving in a specific density as viewed from a specific vantage point

Answer 16

Luminance

Question 17

What are the 3 interactions of light?

Answer 17

Light Source; Viewer; Reflective Surface

Question 18

___ is the sensation produced by an extreme illuminance within the normal field of view that is sufficiently greater than the luminance to which the eyes are adapted

Answer 18

Glare or Reflected Glare

Question 19

____ _____ is the degree of visual satisfaction produced by the luminous environment, resulting from the reduction of glare and distracting illuminance in the field of view

Answer 19

Visual Comfort

Question 20

VCP stands for?

Answer 20

Visual Comfort Probability

Question 21

a VCP < ___-___ is not recommended for general office

Answer 21

70-80

Question 22

Luminares emit light (lumens) in one of 3 directions. What are they?

Answer 22

Downward; Upward; Multidirectional

Question 23

These are all examples of the 7 different ____/_____ types
1. Concentrated Downward(Direct)
2. Diffused Downward(Direct)
3. Concentrated Upward (Indirect)
4. Diffuse Upward (Indirect)
5. Multidirectional Concentrated (Semi Direct or Semi Indirect per amount of light going up or down)
6. Direct/Indirect
7. Multidriectional Diffuse (General Diffuse)

Answer 23

Direction/distribution types

Question 24

___ ___ = sunlight casting shadows and modeling shapes

Answer 24

Direct Light

Question 25

___ ___= softens the shadows and fills the voids

Answer 25

Indirect Light

Question 26

____ results from the intensity of light that intially strikes a surface and the reflecting or transmitting properties of that surface

Answer 26

Brightness

Question 27

Darl/ low reflectance surfaces ____ light

Answer 27

Absorb

Question 28

Light colored, highly reflective finishes ___ much more light

Answer 28

reflect

Question 29

These are all examples of how to ___ ____
1. Limit the amount of light emitted in the direction of the eye
2. Increase the area from which the light is emitted
3. Direct the light away from the main visual field

Answer 29

Reduce Glare

Question 30

______ is an archaic term used to quantify reflected light

Answer 30

Footlamberts

Question 31

What is Grazing light?

Answer 31

When you want to illuminate a textured wall

Question 32

What is Acuity

Answer 32

The ability of an eye to focus

Question 33

what is the difference between direct glare and indirect glare?

Answer 33

Direct glare is right into the eye. Indirect light is a reflection of light off something (such as a computer screen) into the eye.