This spherical image shows the erupting volcano Etna taken from Monte Cagliato. Photography has a particularity because it captures the moment in which a bank of fog reaches the shooting location. The sky and the landscape are not completely covered and the Moon illuminates the environment by brightening it. Yet this is not the main peculiarity of the image. Around the Moon it is possible to observe a series of concentric rings with the shades of the rainbow. They are crowns that form as a result of the scattering and diffraction of moonlight induced by tiny drops of water. Yet these are not actual crowns in the sky. Here the effect was created due to a thin layer of humidity which was deposited on the lens.
Normally these halos have a more diffused and softer appearance than real crowns. Knowing how to distinguish them is important to correctly evaluate the observed physical phenomena.
Interesting right?

Canon 6d, Canon 8-15mm, 30 sec f/4, iso 3200