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Photographer's Note

Sunset is the time at which the sun disappears below the horizon in the west. It should not be confused with dusk, which is the point at which darkness falls, some time after the beginning of twilight when the sun itself sets.
The sunset is often more brightly colored than the sunrise, with the shades of red and orange being more vibrant. The atmosphere responds in a number of ways to exposure to the sun during daylight hours. In particular, there tends to be more dust in the lower atmosphere at the end of the day than at the beginning. During the day, the sun heats the surface of the Earth, lowering the relative humidity and increasing wind speed and turbulence, which serves to lift dust into the air.

The red hues of the sky at sunset and sunrise are caused by Rayleigh scattering, the same mechanism that causes the sky to be blue.
As light travels through the atmosphere, some of it is scattered at large angles by small particles. This type of scattering, where the particles are much smaller than the wavelength, is called Rayleigh scattering. Because Rayleigh scattering is much stronger for shorter wavelengths, like blue, the light from a clear sky is blue. Likewise, as the blue component is scattered out of a ray of sunlight, the remaining light becomes yellower. At sunrise or sunset the light has traveled a long distance through the atmosphere leaving only the longest wavelengths like orange and red. The reddened sunlight illuminates clouds and other particles. The combination of orange and red clouds and the blue sky can produce a variety of colors.
Volcanic eruptions release particles into the atmosphere that affect scattering. A number of eruptions in recent times, such as those of Mount Pinatubo in 1991 and Krakatoa in 1883, have been sufficiently large to produce remarkable sunsets and sunrises all over the world.
Sometimes just before sunrise or after sunset a green flash can be seen.


Model: NIKON D40
Software: Ver.1.10
Exposure Time: 10/600 sec
F-Stop: f/4.5
ISO Speed Ratings: 1600
Focal Length: 34 mm
Date Taken: 2008-05-01 18:21
Metering Mode: Pattern
Flash: Flash fired, auto mode, return light not detected
File Size: 190 kb

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Additional Photos by Paolo Motta (Paolo) Gold Star Critiquer/Gold Star Workshop Editor/Gold Note Writer [C: 3781 W: 144 N: 8843] (41222)
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