Composition as well as preliminary study of digital photos of rainbow
<a href="//commons.wikimedia.org/wiki/User:Alians_PL" title="User:Alians PL">Bronisław Wesołowski</a>
CC BY-SA 4.0
<a href="//commons.wikimedia.org/wiki/User:Alians_PL" title="User:Alians PL">Bronisław Wesołowski</a>