For 50 years now, camera company Nikon has been highlighting microscopic marvels with the annual Nikon Small World photomicrography competition. Headlining this year’s winners is a groundbreaking view of mouse brain tumor cells.

The 50th rendition of the annual competition showcases butterfly wings on the tips of needles and cells from mouse brains.

The winners of Nikon's Small World microphotography competition have been announced. Now in its 50th year, the annual contest zooms in on tiny wonders, featuring images taken through a light microscope. Contestants come from all areas of expertise, ranging from scientists to hobbyists.