Halo Phenomena Explained

Consider the following poorly-put-together diagram, depicting how light refracts off of ice crystals in cirrostratus clouds to form sundogs, 46° halos, and finally 22° halos:

Sundogs are formed when light hits one plane of the ice crystal and exits orthogonally, forming a 60° angle.

A 46° halo may form when light hits ice crystal and exits the bottom, forming a 46° angle.

Lastly, the 22° halo can form when—you guessed it—the light enters and exits forming a 22° angle.