The strongest northern lights photographer Kristjan Unnar Kristjansson had ever seen, over Seltjarnarnes beach in Iceland. A 6 second exposure was used for this picture, when usually 20-30 seconds were required using the same settings. Dancing across the clear skies the amazing aurora borealis are a sight to behold. Icelandic photographer Kristjan Unnar Kristjansson has spent the last nine years capturing the kaleidoscopic light show. Also known as the northern and southern polar lights the natural light displays are governed by sun storms and are usually observed at night. In northern latitudes the effect is known as the aurora borealis, named after the Roman goddess of dawn, Aurora and the Greek name for the north wind, Boreas. [CFP]