| Definition/Meaning | Word/Phrase |
|---|
| tendency for a visual object to be perceived as having the same brightness under widely different conditions of illumination |
brightness constancy
|
| process of adjusting the eyes to low levels of illumination; cones adapt first; rods continue to adapt for up to four hours |
dark adaptation
|
| absence of light or illumination |
dark
,
darkness
|
| microscope with high-intensity illumination |
dark-field microscope
,
ultramicroscope
|
| normal vision in daylight; vision with sufficient illumination that the cones are active and hue is perceived |
daylight vision
,
photopic vision
|
| rheostat that varies the current through an electric light in order to control the level of illumination |
dimmer
|
| device that produces a bright light for warning or illumination or identification |
flare
|
| light that is a source of artificial illumination having a broad beam; used in photography |
flood
,
flood lamp
,
floodlight
,
photoflood
|
| beam of a car's headlights that provides distant illumination |
high beam
|
| measure of illumination |
illumination unit
|
| condition of spiritual awareness; divine illumination |
illumination
,
light
|
| cgs unit of illumination equal to the brightness of a perfectly diffusing surface that emits or reflects one lumen per square centimeter |
L
,
lambert
|
| artificial source of visible illumination |
lamp
|
| process of adjusting the eyes to relatively high levels of illumination; the pupil constricts and the cones system is operative |
light adaptation
|
| any device serving as a source of illumination |
light
,
light source
|
| having abundant light or illumination |
light
,
lighting
|
| visual effect of illumination on objects or scenes as created in pictures |
light
,
lightness
|
| beam of a car's headlights that provides illumination for a short distance |
low beam
|
| unit of illumination equal to 1 lumen per square meter; 0.0929 foot candle |
lux
,
lx
|
| game played under artificial illumination at night |
night game
|
