The talk starts with the ideas explaining how rainbows are formed and then goes on to explain a variety of other atmospheric phenomena such as haloes, glories, sun dogs, the green flash etc.

Many of the optical phenomena which can be seen in the atmosphere are produced by reflection and refraction through water droplets or through ice crystals. Raindrops are of just the right size to produce rainbows. As the radius decreased so the rainbow becomes less clear, eventually losing the colours in a fog bow. As the radius gets smaller still then we are able to see glories. Haloes are produced by light passing through ice crystals. Such crystals are hexagonal and there is a wide variety of possible paths through these crystals leading to different types of halo phenomena.