Lighting Exam 1

¡Supera tus tareas y exámenes ahora con Quizwiz!

The Illuminance recommendation for offices is 30 fc. In general, since more than half of the population's age in offices is between 25 and 65, the illuminance provided should be:

30 fc

The candela (or candlepower) is the unit used for luminous intensity. Luminous intensity is adensity that is best described by which of the following expressions?

lumens per steradian

The three types of cones are labelled L, M, S, for their response to long, medium and short wavelength ranges. The response to a particular color is the result of the individual response of each of these cones.

True

The visible spectrum is bounded by ultraviolet (UV) radiation on one side and in infrared (IR) radiation on the other.

True

True or false: In the IES TM-30 system, the R(f) metric has a range of values from 0 to 100.

True

The property of radiant power waves that most closely corresponds to our perception of color is

Wavelength?

The accumulation of dirt on a luminaire directly affects this value

light loss factor

True or false: The IES Illuminance Recommendations ensure that tasks receive enough light without wasting energy to maintain task performance constant on the plateau per the relative visual performance model. Because of this, the age of the viewer is not relevant.

False

True or false: The cornea provides adjustable focusing power, while the lens provides most of the focusing power.

False

True or false: The lighting quantities of illuminance and exitance both have units of lumens per area, with area in square feet or square meters. For both illuminance and exitance, the footcandle is used as the unit when the expression is lumens per square foot.

False

True or false: The term "brightness" means the same thing as the term "luminance"

False

The 'E' in the formula above corresponds to

Illuminance

The IES is the body in the lighting industry that sets the standards for lighting practice. IES stands for:

Illuminating Engineering Society

If the light meter indicates that there are 35 fc on the desk, the equivalent in lx is?

350 lx

Color mixing with light is known as

Additive

Luminous intensity coming from a light source has units of

Candela (Candlepower or lumens per steradian)

When you are looking at a small object, at which part of the retina is the image being focused?

Fovea

Color preferences seem to be mostly affected by the saturation level of which hues?

Red

Another word for chroma is

Saturation

A lobby has a wall insert of highly polished chrome. Light reflected from this surface is an example of what type of reflection?

Specular

Per the previous question, what would happen to color space if the RGB primaries would be moved closer together?

The range of colors that could be represented would decrease

True or false: Color constancy is a mechanism by which chromatic signals are compared across most of our field of view, therefore we can extract information about the color of an object correctly in spite of the spectral composition of the source illuminating the object

True

1. Which of the following is not one of the forms of lightplay defined by Richard Kelly? a. Ambient luminescence b. Layers of light c. Focal glow d. Play of brilliants

b. Layers of light

If the E of a light source at a point is 30 fc and the source is 10 ft. away, what is the intensity of the source?

.3?

The solid wood paneling in a hotel room has a reflectance value of 0.25. The transmittance value is what?

0.0?? Or .75

True or false: According to Flynn, impressions of privacy can be reinforced by bright lighting that emphasizes central architectural surfaces.

False

True or false: According to the IES, the recommended illuminance for a kitchen counter with a critical task is 50fc. This value in lux would be 5 lx.

False

True or false: Additive color mixing means the combination of light beams with different spectral components. If I were to mix yellow and blue light I get green.

False

True or false: In the IES TM-30 system, the R(g) metric has a range of values from 0 to 100.

False

True or false: Research shows that we have a preference for red saturation. The more saturated the color the more we like it.

False

True or false: The IES Illuminance Recommendations ensure that tasks receive enough light without wasting energy to maintain task performance constant on the plateau per the relative visual performance model. Because of this, the age of the viewer is not relevant.

False

True or false: The SPD curve for a light source describes the potential for providing the appropriate density of light; SPD means Source Potential Distribution

False

True or false: The bending of light as it is transmitted through glass is know as absorptance

False

True or false: The lumen rating of a light source expresses its total output without considering the human visual system; it is a sum of the radiant power across all wavelengths.

False

True or false: The photoreceptors providing the ability to see color objects are the cones; they are plentiful in the periphery of the retina, more so than the rods which are concentrated in the fovea.

False

True or false: The photoreceptors providing the ability to see color objects are the cones; they are plentiful in the periphery of the retina, more so than the rods which are concentrated in the fovea.

False

True or false: The type of photopigment or "opsin" indicates the photoreceptor 's response to light. There are five types of "opsins", one of them being melatonin.

False

True or false: The type of photopigment or "opsin" indicates the photoreceptor's response to light. There are five types of "opsins", one of them being melatonin.

False

True or false: a light source converts radiant power (Watts in) to electric power (Watts out). The efficiency of the light source is determined by the ratio of these two.

False

According to color vision theory, a B-Y receptive field could have a blue excitatory center and a yellow inhibitory surround but not the other way around.

False (To summarize: the B-Y channel = S - (L + M); the G-R channel = M - (L + S); the Luminance channel = L + M)

True or false: light source converts radiant power (Watts in) to electric power (Watts out). The efficiency of the light source is determined by the ratio of these two.

False (electric power--->radiant power

True or false: The main difference between Exitance and Luminance is that Exitance doesn't tell us what we see.

False?

One of the IES TM-30 color rendering metrics measures how well a set of test colors under a light source match their appearance under a reference light source. This type of color metric is a measure of:

Fidelity

A campfire, a follow-spot in the theater, and an airplane seat light are all examples of

Focal Glow

For the example where source 2 has lower intensity and the same size as source 1, what statement best describes the relationship of the luminance of source 2 compared to source 1?

The luminance of source 2 is less than the luminance of source 1

For the two light sources discussed which have the same intensity and size, but different spectrum, which statement best describes the relationship between the luminances?

The luminance of source 2 is the same as the luminance of source 1

True or False: According to Flynn, impressions of spaciousness can be reinforced by uniform lighting that emphasizes perimeter architectural surfaces.

True

True or false: A metameric match tells us that two colors can be perceived as being the same, even when their spectral components are different from each other.

True

True or false: Cones and rods do not send their individual responses up the chain of information. Instead, the signals are combined into opposite color channels. This is the fundamental way color vision occurs.

True

True or false: Cones are wired to various ganglion cells; the same cones send information from more than one receptive field, and these fields can overlap.

True

True or false: If the fidelity of a source is different from that of a reference source, meaning that the Rf value for that source is less than 100, it is possible that colors rendered under it would result in higher preference and better discrimination.

True

True or false: Illuminance changes (diminishes or increases) with distance and angle of incidence.

True

True or false: Illuminance is derived from the lumen, which in turn it is based on the photopic efficiency curve V (Lambda). A multiplier is necessary to adjust for the fact that when our eyes are mesopically adapted, our eyes are more sensitive to longer wavelength.

True

True or false: In general, people prefer colors that are more saturated than they appear under the reference light source.

True

True or false: In order to account for the light not hitting a surface perpendicularly we add the cosine of the angle to the Inverse Square Law formula.

True

True or false: Our visual system can only see a portion of optical radiation.

True

True or false: The Lumen Method only works if the light in the space comes from a uniform ceiling layout

True

True or false: The formula for the Inverse Square Law is E = I / D2

True

True or false: The problem with referring to the cones as L, M, S is that by doing so we imply that the cones are most sensitive to red, green and blue wavelengths.

True

True or false: The problem with referring to the cones as L, M, S is that by doing so we imply that the cones are most sensitive to red, green and blue wavelengths.

True

True or false: The reference light source used for establishing color rendering metrics is called the blackbody radiator.

True

True or false: The third parameter of a three-dimensional color space is luminance.

True

True or false: The three types of cones are labelled L, M, S, for their response to long, medium and short wavelength ranges. The response to a particular color is the result of the individual response of each of these cones.

True

True or false: The types are photoreceptors are rods, cones and ipRGCs

True

True or false: The visible spectrum is an example of one-dimensional color space. Here, I can map the color perception of a monochromatic light such as yellow, for example; its parameter would be 580 nm. [Assume that 580 nm is an accurate number for pure yellow.]

True

The lumen is defined based on ______________ also known as ______________ curve.

V (lambda) | photopic

Definition of light:

Visually evaluated radiant energy OR spectral stimulus that produces a visual sensation via the interaction with materials

Electric power going into a light source has units of

Watts

Radiant power coming from a light source has units of

Watts

True or false: The process whereby the eye focuses incoming light on to the retina is called adaptation. The process that allows the eye to adjust to the amount of light is called accommodation.

false

Footcandles and lux are both units of illuminance. Which of the following best describes the quantity expressed by footcandles?

lumens per square foot

Lumen output of the luminaire directly affects this value A. Coefficient of utilization B. Light loss factor C. Room Cavity Ration D. None of the above

none of the above

If the amount of light arriving to the eye is high, the ________ aperture will reduce in size as the _________ relaxes and closes down,

pupil, iris

If the amount of light arriving to the eye is high, the ________ aperture will reduce in size as the _________ relaxes and closes down.

pupil, iris

The three primary colors of light are

red, green, blue

The Lumen Method allows a designer to calculate _____?

The average illuminance over an entire area.

Suppose that you wanted to produce an illuminance of 200 footcandles on a statue, from a light source that is mounted 10 ft from the statue. What value of luminous intensity do you need coming from the light source in the direction of the statue?

20000cd

The Lumen Method allows a designer to determine the ____________ level of light level over a(n) ______________. a. Initial / Rectangular area b. Maintained / Given point c. Average / Entire area

c. Average / Entire area

Which of the following is not one of the Flynn lighting modes? a. Intensity: Bright / Dim b. Color tone: Warm / Cool c. Daylight: Windows / No windows d. Distribution: Uniform / Non-uniform e. Emphasis: Central / Perimeter

c. Daylight: Windows / No windows

If the total LLF is 0.80 and the CU is 0.80. What is the new resulting E?

32 footcandles? Using numbers from previous equation: (10)(2000)(.8)(.8)/(20)(20)

The wavelength range for visible light (in nanometers) within the electromagnetic spectrum is:

380 to 700 nanometers

An office is 15 ft by 15 ft with two luminaires, each of which has lamps producing 6000 lumens. If the CU value for the luminaires is 75% for the desktops, what is the estimated average illuminance on the desktops? - 40fc. For the same luminaire used in #9 (6000 lumens output), the CU value for a 20' by 30' room is 0.80. How many luminaires would you need in this larger room to achieve an average illuminance of 64 fc?

3:8

A light source has luminous intensity of 1000 candlepower at the center of its beam, and is mounted five feet above a table. The estimated illuminance on the table directly beneath the light source is:

40 lux

An office is 15ft x 15ft with two luminaires, each of which has lamps producing 6000 lumens. If the CU value for the luminaires is 75% for the desktops, what is the estimated average illuminance on the desktops?

40fc

A 20 x 20 ft. room has 10 luminaires. Each luminaire has 1 lamp, which produces 2000 lm. What is the resulting E?

5 footcandles? (10)(2000)/(20)(20)

The IES TM-30 color rendering method uses a set of how many test colors?

99

A snowy morning, haze at twilight, and the diffuse light from the fabric structure at DIA are all examples of

Ambient Luminescence

When you are looking at a colorful object, which photoreceptors are providing the ability to see colors?

Cones

The transparent, bulged covering at the front of the eye that provides refractive power for focusing light is the

Cornea

A wall in an office space has a flat off-white paint finish. Light reflected from this surface is an example of what type of reflection? a. Specular b. Refractive c. Diffuse d. Semi-Specular

Diffuse

The formula for the Inverse Square Law is?

E=cp/d squared

An example of a _________ texture is the skin of an apple

Mircro-macro

One of the IES TM-30 color rendering metrics measures how the color saturation of a set of test colors shifts compared to their appearance under a reference light source. This type of color metric is a measure of:

Gamut

If test colors under a light source appear to be more saturated than under the reference light source, the R(g) metric is

Greater than 100

The radiant power of a light source takes form in waves that have two distinct properties:

Height of the wave and the distance between the peaks of such wave

The density of light onto a surface is defined as illuminance. Moving the light farther away from a surface causes which of the following to happen?

Illuminance decreases

What does IALD stand for?

International Association of Lighting Designers

What does CIE stand for?

International Commission of Illumination

What does ipRGCs stand for

Intrinsically photosensitive retinal ganglion cells

This calculation method is used to estimate the illuminance at a specific point & this calculation accounts for direct light only

Inverse square cosine law method

The opening in the eye that changes in size to adjust to different levels of light is the

Iris

The part of the eye that is pigmented, resulting in differences in eye color is the

Iris?

The part of the eye that provides adjustable focusing power is the

Lens

Task categories describe the level of task difficulty going from A to Y. A task labelled C will be __________ difficult than a task labelled R. (more/less/equally?)

Less

Luminous power coming from a light source has units of

Lumens

What does NCQLP stand for?

National Council on Qualifications of the Light Professions

The window in a hotel room has a reflectance of 0.25. The transmittance value is what?

Not enough information

The rod photoreceptors are primarily located in which part of the retina?

Periphery

Christmas tree lights, crystal chandeliers, and a sparkling water feature are all examples of

Play of Brilliants

A two-dimensional color space maps perceptions of light produced by a combination of primary colored lights ( ___________) in different _____________.

R, G, B | amounts

The density (amount) of light coming off of a surface is largely a function of: Matte surfaces Reflectance Diffusion Surface textures

Reflectance

The inner part of the eye that contains the photoreceptors that are responsible for sensing light is the

Retina

When you are in very dark room, which photoreceptors are helping you see?

Rods

The height and proportions of a room are used to calculate this value

Room cavity ratio

The IES TM-30 color gamut metric R(g) expresses how a light source affects which aspects of the color appearance of objects?

Saturation

The tough covering that protects the internal portions of the eye and maintains the spherical shape (but does not transmit light) is the

Sclera

My kitchen has a polished hardwood floor. Light reflected from this surface is an example of what of what type of reflection?

Semi-specular

If a signal activates both channels (R-G and B-Y) the resulting color I perceive would be:

Something other than blue, yellow, green, red

If a surface color is defined by C = r R + g G + b B, what happens to the color perception if the visual system is presented with this: 2r R + 2g G + 2b B?

The color stays the same but it's colorfulness (saturation) and lightness will increase.

The Lumen Method allows a designer to calculate _______.

The average light over an entire area

The curve that is commonly called, "V-lambda," which is best described by which of the following?

The human visual response as a function of the wavelength of light

This calculation method is used to estimate the average illuminance on a work plane & this calculation ,accounts accounts for both direct and inter-reflected light

Zonal Cavity Method

The formula above is used to find E at a point when the light hitting the surface is perpendicular. What needs to be added to the formula in order to account for the light hitting a slanted (not perpendicular) surface?

cosign?

The RGCs carry ______________ to the __________ from the _____________ . The ipRGCs are also ________________, but their information is ____________ forming.

information | visual cortex | rods and cones | photoreceptors | non-image

The RGCs carry ______________ to the __________ from the _____________ . The ipRGCs are also _______________, but their information is ____________ forming.

information | visual cortex | rods and cones | photoreceptors | non-image

The reflectance values of room surfaces directly affect this value

inverse square cosine law method

Which photoreceptors connect to the non image forming parts of the brain?

ipRGCs


Conjuntos de estudio relacionados

EEL 4804 Intro to Malware Reverse Engineering

View Set

Unit 11: Involuntary Liens And Homestead

View Set

Chapter 12: Dimensions of Marketing Strategy

View Set

Unit 4 4.2 Prokaryotic cells do not have a nucleus

View Set

Roll of Thunder, Hear My Cry Chapters 1 -3

View Set