Daylight

From Fiswiki

Jump to: navigation, search
Daylight or the light of day is the combination of all direct and indirect sunlight outdoors during the daytime (and perhaps twilight). This includes direct sunlight, diffuse sky radiation, and (often) both of these reflected from the Earth and terrestrial objects.
Daylight or the light of day is the combination of all direct and indirect sunlight outdoors during the daytime (and perhaps twilight). This includes direct sunlight, diffuse sky radiation, and (often) both of these reflected from the Earth and terrestrial objects.

Daylight or the light of day is the combination of all direct and indirect sunlight outdoors during the daytime (and perhaps twilight). This includes direct sunlight, diffuse sky radiation, and (often) both of these reflected from the Earth and terrestrial objects.

Sunlight scattered or reflected from objects in outer space (that is, beyond the Earth's atmosphere) is generally not considered daylight.

Moonlight is the light that comes to Earth from the Moon. This light does not originate from the Moon, but actually originates from sunlight. The Moon does not, however, reflect sunlight like a mirror, but it emits light from those portions of its surface which the Sun's light strikes.
Moonlight is the light that comes to Earth from the Moon. This light does not originate from the Moon, but actually originates from sunlight. The Moon does not, however, reflect sunlight like a mirror, but it emits light from those portions of its surface which the Sun's light strikes.
IlluminanceExample
120,000 luxBrightest sunlight
110,000 luxBright sunlight
20,000 luxShade illuminated by entire clear blue sky, midday
10,000 - 25,000 luxTypical overcast day, midday
<200 luxExtreme of darkest storm clouds, midday
400 luxSunrise or sunset on a clear day (ambient illumination).
40 luxFully overcast, sunset/sunrise
<1 luxExtreme of darkest storm clouds, sunset/rise

For comparison, nighttime illuminance levels are:

IlluminanceExample
<1 luxMoonlight
0.25 luxFull Moon on a clear night
0.01 luxQuarter Moon
0.002 luxStarlight clear moonless night sky including airglow
0.0002 luxStarlight clear moonless night sky excluding airglow
0.00014 luxVenus at brightest
0.0001 luxStarlight overcast moonless night sky


[edit] Also See


Return to Snow and Weather Glossary, Working with Snow, Freestyle Skiing

Personal tools