Rainbow in the Cairngorms
A rainbow appears over the forests near Loch Morlich in the Cairngorms (Cairngorm National Park, near Aviemore, Scotland UK).
I slightly enhanced the colours using a circular polarizing filter. Depending on the position of such a filter, it will either enhance the colours - or even eliminate the rainbow effect!
(A polarizer actually consists of two glass filters that are rotated against each other and is very useful for eliminating or enhancing all sorts of reflections)