Green Flash Sequence from Messina, Italy
September 25, 2019
Photographer: Fabio Di Stefano
Summary Author: Fabio Di Stefano
This green flash sequence was observed from Messina, Sicily, Italy at sunset on July 11, 2019. As its name implies, a green flash is a brief burst of emerald light that can sometimes be detected as the Sun grazes the horizon during sunset or sunrise. This spectacle results from atmospheric dispersion: Various colors of light bend different amounts based on their wavelengths; shorter wavelengths (blue, violet and green) refract more strongly than longer wavelengths (yellow, orange and red). As separate images of each spectral color are generated, the uppermost rim of the Sun will momentarily flash green, particularly if the observer is overlooking the sea.
Photo Details: Canon EOS M6 camera; Canon 70 200 mm lens, f4; L USM at 200 mm, f/8; 400 ISO; exposure time variable to maintain the optimal exposure between the first and the last image.