Diving deep into Iridescence.

Iridescent clouds are a diffraction phenomenon caused by small water droplets or small ice crystals individually scattering light. Larger ice crystals do not produce iridescence, but can cause halos. The cloud must be optically thin, so that most rays encounter only a single droplet. Iridescence is therefore mostly seen at cloud edges or in semi-transparent clouds, while newly forming clouds produce the brightest and most colorful iridescence.

This image was captured almost 2 years back and I have processed it multiple times, and finally I'm pretty happy with it. At a high focal length, it captures a very small part of what was a larger structure.

Stack of 5 images
Exif: f/6.3, 1/80s, ISO 250, 600mm
Gear: Nikon D5600, Sigma 150-600c
Location: Kolkata, India
Date: 21st May 2021

Nikon D5600, Sigma 150-600c

Photoshop