Daylight
From FIS Freestyle wiki
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.
Illuminance | Example |
---|---|
120,000 lux | Brightest sunlight |
110,000 lux | Bright sunlight |
20,000 lux | Shade illuminated by entire clear blue sky, midday |
10,000 - 25,000 lux | Typical overcast day, midday |
<200 lux | Extreme of darkest storm clouds, midday |
400 lux | Sunrise or sunset on a clear day (ambient illumination). |
40 lux | Fully overcast, sunset/sunrise |
<1 lux | Extreme of darkest storm clouds, sunset/rise |
For comparison, nighttime illuminance levels are:
Illuminance | Example |
---|---|
<1 lux | Moonlight |
0.25 lux | Full Moon on a clear night |
0.01 lux | Quarter Moon |
0.002 lux | Starlight clear moonless night sky including airglow |
0.0002 lux | Starlight clear moonless night sky excluding airglow |
0.00014 lux | Venus at brightest |
0.0001 lux | Starlight overcast moonless night sky |
[edit] Also See
Return to Snow and Weather Glossary, Working with Snow, Freestyle Skiing