My friend Audrey recently asked me to join her in writing for her new blogsite which she has initiated for sharing of creative inspiration, called 365 Just Show Up. This image is one I posted there recently, after an early morning shoot with friends near Palm Beach in Sydney's north.
With photography, light and timing is everything. And sometimes that means 'showing up' when the rest of the world is sleeping. This weekend, fellow photographers Richard, Anastasia and Vlad and I arranged to meet near Palm Beach on Sydney's northern beaches area, to catch the sunrise over the water. We needed to arrive at the location somewhere between Astronomical Twilight (which was 5.17am on 7/8/10) and Nautical Twilight (5.46am on 7/8/10), in order to scout the location, get set up, and have an hour's shooting time in the magical pre-dawn light.
For those of a technical mind, Twilight has 3 defined phases: Astronomical, Nautical and Civil that refer to specific points in 6° increments of the sun's angle to the horizon before sunrise and after sunset. Each phase lasts approximately half an hour. (Australian readers can use this Geoscience Australia calculator to obtain the Sunrise / Sunset and Twilight times.)
Astronomical Twilight = the instant in the morning (or evening) when the centre of the sun is at an angle of 18° below the horizon. At this time it is possible to still see the light of stars in the sky.
Nautical Twilight = when the centre of the sun is at an angle of 12° below the horizon. At this time in the absence of moonlight, artificial lighting or adverse atmospheric conditions, it is dark for normal practical purposes. For navigation purposes at sea, the sea horizon is not normally visible. (Occurs approx. half an hour after Astronomical Twilight)
Civil Twilight = when the centre of the sun is at a 6° angle below the horizon. At this time in the absence of moonlight, artificial lighting or adverse atmospheric conditions, the illumination is such that large objects may be seen but no detail is discernible. The brightest stars and planets can be seen and for navigation purposes at sea, the sea horizon is clearly defined. (Occurs approx. half an hour after Nautical Twilight)
Sunrise: (Occurs approx. half an hour after Morning Civil Twilight)
The reverse occurs in the Evening: Sunset, Civil Twilight, Nautical Twilight, Astronomical Twilight, fading into the darkness of night.