At sunset, the sun appears red (the blue light has been scattered out of that image, too), so the cells of the eye that detect red are overloaded and incapable of registering weaker red signals.

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The indoor lighting levels in their enclosures now simulate those of natural light levels, in line with sunrise and sunset.

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This hybrid system guarantees the photographer sharp, blur-free images even under demanding shooting conditions prone to camera shake, such as when using a telephoto lens, shooting with incident light in poorly lit locations, or photographing sunset scenes.

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This hybrid system assures the photographer of sharp, blur-free images and video even under demanding, camera-shake-prone shooting conditions, such as when using a telephoto lens, shooting with incident light in poorly lit locations, or photographing sunset scenes.

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The planet, 200 million light years away, orbits two stars rather than one and so enjoys a double sunset.

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Irregularly shaped windows in the karsheef walls provided natural light, and a stack of thick candles indicated where illumination would come from after sunset.

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The electric light bulb has made darkness optional, eliminating the enforced idleness that used to begin at sunset.

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