The glory
The glory is comparable to the cloud corona (by sun or moon). Both the glory and
corona are caused by diffraction of light around droplets. The glory, however,
occurs around the antisolar point, and is much easier to photograph because it is
far from the sun (or moon). However, the glory is also very difficult to observe,
since it is below the horizon, and you will only see it when you are in sunlight
above a cloud.
A bright glory as seen from an airplane, on an altocumulus deck. Up to 3 diffraction
rings can be seen.
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Where to look for the glory
When flying in an airplane, this situation exists. The glory, in fact, is very
commonly observed by travelers nowadays. The next time you are flying in an
airplane, book yourself a window seat on the shadow-side of the aircraft; if the
sun is not too high in the sky you will see the colorful glory around the point
opposite the sun (where the shadow of the airplane is).
The glory may also be seen when you are on a mountain and above a cloud or fog.
Such glories are very spectacular, because they are nearby, and generated by
a small area of cloud with similar droplets (as opposed to a large area, which
may differ in droplet composition).
Clouds which show glories well are the same clouds that show corona and
iridescence well: cirrocumulus or altocumulus lacunosus, lenticular clouds,
and (fresh) stratiform clouds.
Photography
Photographing the glory is easy. However, in an airplane you will be moving fast,
so fast shutter speeds are recommended in order to have the clouds sharp on the
photo.
You can use a lens ranging from 28-150mm, albeit that the 80-150mm lenses will
show the glory best. But don't zoom in on the glory too much, since there may
be higher-order colored rings which would be out of view.
At night you have a slightly higher chance to see the glory (and corona) in fog
by the moon. For this you should wait for a night with no wind and clear air,
during full moon; surface fog will form; and if the moon is low in the sky,
you have a chance to see the glory. Do a time-exposure of the antiselenic
point (where your shadow is), because maybe you don't see the glory but it will
record on a time-exposure.
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