Definition of Twilight
With some relief that the Inland Northwest has received a normal ration of snow, we can look forward to composing images for the Winter Scene at Twilight subject for March. But what is twilight? Harvey Brown submitted a clear definition:
twilight: the light from the sky between full night and sunrise or between sunset and full night produced by diffusion of sunlight through the atmosphere and its dust.
There are 3 stages of twilight that occur before sunrise or after sunset as follows:
- Civil: 30-35 min. after sunrise/sunset
- Nautical: Next 40 min. after Civil
- Astronomical: Next 40 min. after Nautical