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30 Cards in this Set
- Front
- Back
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Name 3 factors that can affect the perceived color in a room? |
What can these factors affect? Time of day sky condition geographic location time of year direction of light |
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Ideal design has a balanced ____________ of light. |
Ideal design must have a _____________spectrum of light. |
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What is chromacity? |
Color temperature is ____________________. |
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What is the temp in Kelvin for neutral (daylight) |
________________ has a temperature of 3500k |
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What color temperature range is considered warm? |
2000k to 3200k provides _______ apparent light |
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What color temperature is considered "cool"? |
What color temperatures do lights in the 4100k-5500 K provide? |
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What are common chromacity ratings for fluroescent sources? |
3000k, 3500k and 4100k are common temps for which sources of light? |
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What is a CRI? |
Color Rendering Index |
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What does the CRI measure? |
What measures how faithfully a light sources reveals the true colors of objects? |
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What are Initial Lumens? |
What is the light output when the luminaire is initially installed? |
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What are the mean lumens? |
What is the average light output over the life of the lamp? |
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Define brightness |
Illumination + reflectance = |
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Define reflectance. |
What is the amount of light reflected off various surfaces? |
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Define a footcandle. |
The amount of light that falls on a surface within a 1-foot radius of the source. |
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What is another name for footcandle (fc)? |
What is another name for lux (lx) |
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Name at least 3 factors that affect brightness. |
What can the following affect? reflectance illuminance location of the source context (cloudy day vs. sunny day) vision of user source of light, characteristics of the element in space subjectivity based on experience |
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Define glare. |
Define excessive brightness |
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An unshielded lamp greater than 25 watts will cause glare. |
True |
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What is a veiling reflection? |
Define: Indirect light that is reflected from a surface in a task area. |
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What is the difference between discomfort glare and disability glare? |
Glare from a naturally or electric light source that is uncomfortable but still allows an individual to see objects and complete a task vs. glare so severe that a person cannot see |
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Name 3 ways to control glare. |
Increased number of lower wattage lamps, locating luminaires out of the field of vision, using shades, baffles and louvers or lenses or awnings are all ways to ______________. |
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Define the angle of incidence. |
What is the: angle at which rays of light emitted from a light source strike an object or surface before reflection. |
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When does interreflection occur? |
When light is contained within a structure an is continuously reflected from its surfaces, it is called ________________________. |
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What is specular reflectance and what can it cause? |
The result of all of the light falling on a (glossy) surface is reflected. It can cause discomfort or disability glare. |
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When is semi-specular reflectance observed? |
When most of a light is reflected from an etched or irregular surface (like a hammered finish). |
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When does diffused reflectance occur? |
When light is scattered at a variety of angles (light hitting a matte surface). |
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Name 3 types of reflector lamps. |
R, PAR, MR are what kind of lamp? |
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What are some common shapes for luminaires with reflector contours? |
Ellipses, parabolas and circles are shapes for these types of luminaires. |
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What is the term used to describe the passage of light through a material? |
Transmission |
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What are the 3 types of transmission of light? |
Direct, diffused and mixed are three types of ________________. |
