The glory is not a full circle rainbow. A full circle rainbow also is centered at the shadow of the observer however its angular diameter is $84^\circ$ whereas the angular diameter of the glory is less than $20^\circ$. Unlikely the rainbow the glory cannot be explained just in terms of geometrical optics.

Sep 20, 2023 · A glory is the technical name for a full circle rainbow, such as is sometimes (but rarely) seen from below above a waterfall, or below from above a cloud. I am asking this question here. because it concerns an optical device I once owned, and an optical phenomenon I could never understand.

Sep 11, 2023 · Consider the atmospheric optical phenomenon appearing in this video. A screenshot at the appropriate time is shown below: A screenshot at the appropriate time is shown below: The video is footage from a drone flying just above a low-lying, thin layer of wispy clouds, over an icy water body.

Aug 21, 2017 · It's much more consistent with pictures of a glory (rainbows have a much wider circle they form due to their mechanism). It's an interference pattern caused by refraction of light in the small droplets. I also meant to add this to my answer. What is the explanation of the glory (optical phenomenon)? (Diracology also linked in comments).

Aug 7, 2022 · This reminded me of the optical effect of a halo which can sometimes be observed when looking at the sun or moon, but the reason for these phenomena is due to refraction from light crystals in the air, which is different to what is being observed here (or maybe it is the same).

Jan 20, 2015 · A rainbow is an optical and meteorological phenomenon that is caused by reflection, refraction and dispersion of light in water droplets... Given that we require reflection, refraction and dispersion to take place, I was quite intrigued when I saw that the reflection of light on the TV has scattered into a rainbow. This is how the light looks like:

May 5, 2023 · What is the explanation of the glory (optical phenomenon)? 1 What determines the colour of viewed light that has been linearly then circularly polarised and viewed through a linear polarising filter?

Mar 3, 2017 · Wilson started to develop the Cloud Chamber in the late 19th to reproduce the optical glory. He soon recognized it could be used to detect particles. In 1911 he perfected his device to take pictures and started tests with X-rays and beta particles.

Feb 2, 2021 · There is a proper explanation of this phenomenon in atoptics: Shadows in the sky appear by perspective effects to converge towards the antisolar point, which is also the centre of rainbows. When clouds or dense rain showers shadow the light falling into your rainbow cone the shadowed raindrops can no longer send the rainbow's rays towards your eye.

According to the Wikipedia article, this phenomenon occurs because all the light coming through from the sun at that time is collimated and susceptible to atmospheric scattering effects. Does a crescent moon have the same properties as a "crescent sun," and if so, would it at least in theory be possible to detect extremely faint shadow bands ...