One of my favourite times for taking photos is at twilight. Especially during the spring and summer, the seasons when the light is at its most magical at this time of evening.
I’ve always liked the idea that great photography happens on the edges. Twilight, the transition between night and day, is an edge. While the low light levels can be technically challenging, the reward in terms of quality of light are well worth it. I think of it as the ‘magic hour’. You may also see it referred to as the blue hour, a reference to the colour of the ambient light as night falls.
What is twilight?
Twilight is the time that marks the transition between day and night. It starts after the sun has set and continues until night completely falls. The quality of light during twilight can be truly beautiful, especially after a bright sunny day. The duration depends on your distance from the equator. In the tropics night falls very fast and twilight is short. Go far enough north (or south) in the summer and it can last for over an hour.
Read more: http://digital-photography-school.com/the-magic-of-natural-light-twilight#ixzz2e2pH13QX