Small White Butterfly (Pieris rapae) 

The Small White is a highly mobile species and each year the resident population is boosted by individuals flying in from mainland Europe. It is a common visitor to gardens where it breeds on brassicas and Nasturtium, though it relies less on cultivated brassica crops than the Large White and breeds on a range of wild foodplants. Adult butterflies are attracted to white flowers where they feed and on which they are well camouflaged when roosting. This is a common and widespread species. 

This image was taken in my back garden the butterfly was attracted to a rather sad looking budhlia flower, which luckily for me was not over-looked by any other plant. It was therefore easy to isolate the butterfly against a rather even coloured sky. I illuminated using a ring flash and balanced the output to the sky, the ring flash is great for macro work as it produces almost shadowless lighting.