Olar Barndõk's Image

When drops of rain in the air refract sunlight in a particular way and are seen from a particular vantage point, a rainbow appears in the sky.

As the droplets get smaller, the way the light is dispersed changes, and the arc's colours weaken. If the droplets are less than 0.05mm - if there is mist or fog rather than rain - the arc can become almost entirely white. Olar saw this magnificent fogbow on a trip to the Sibillini Mountains National Park in Italy. The valley was a mass of flowers, poppies, cornflowers and ox-eye daisies. 'After a cold June night, a layer of fog lay over the meadow,' he says. 'After sunrise, it started to lift, and this fogbow appeared. It was so big that I had to use two stitched images to do it justice. Its appearance changed minute by minute as the sun came up, and I knew I had to work quickly. Ten minutes later, the show was over.'