Nikon's annual Small World competition showcases images of a world that humans can't usually see, as captured through the lens of a microscope.

A mouse's tumours, scales from a butterfly's wings and a smiling cross-section of a bracken fern are some of the incredible images from the Nikon Small World photography competition

From spines on neurons to pollen on an insect’s eye, the winners of Nikon’s Small World photo contest offer a kaleidoscopic glimpse into a tiny world.