Meravigliose iridescenze sulle scie di condensazione di un aereo riprese da Soumyadeep Mukherjee, che così scrive:

“And finally, I was able to capture my dream shot. I had always wondered about rainbow contrails, and incidentally, I was checking some images on the day. In the afternoon, I went to the terrace planning to capture the ISS transit of the sun. However, thanks to clouds, the sun wasn’t visible at the time of the transit. But nature never disappoints. I was able to capture this optical phenomenon for the first time in my life. This phenomenon is considered to be extremely rare in countries like India and I might be the first person to capture this in the country.
Aircraft contrails have two sources. The major one is water droplets condensed from water vapour generated in the engines. Combustion of aviation fuel gives water vapour, carbon dioxide and traces of NOx and soot. The second generator is water vapour already in the air condensed to droplets by airflow over the fuselage and wings. Air passing over the top of wings or convex fuselage sections travels faster, expands and cools. Sometimes, if the air is sufficiently humid, water vapour then condenses out into a fine droplet mist. The iridescent colours are produced by individual water droplets diffracting sunlight. When the droplets are locally of similar size they all diffract their coloured light into the same direction and so colours become evident to us. (Les Cowley, Atmospheric Optics)
The final image is a collage of 7 individual images captured over a period of 40 seconds showing some changes in the iridescent colours and also in the contrail shape.”

Gear: Nikon Z6II, Sigma 150-600c
Location: Kolkata, India
Date: 19th July 2023
Per approfondire il tema delle Iridescenze consigliamo di leggere l’articolo: