Scottish photographer Nick Sidle loves the creative opportunities that aerial photography provides. And in recent years, he's become a fan of drone photography, which provides more flexibility than having to organize shoots from airplanes or helicopters. His success in the field is exemplified by a recent image, in which he captured a rare full-circle rainbow.
Sidle was up at dawn taking photos in the Scottish Highlands when the opportunity presented itself. “Although, in theory, all rainbows optically are full circles, the true full circle phenomenon I have been told is rarely seen,” he tells My Modern Met. “From the ground, this rainbow although appearing closer than average, only looked like the usual half-circle. Watching the feed from the drone as it climbed steadily, the lower half was revealed. Personally, this was a first, even from the air I had never seen a full circle, full-scale rainbow.”
As the rainbow was so close, it wasn't possible to fit it all into one shot. Not wanting to risk breaking the illusion by changing the angle or losing the view through the clouds, Sidle made the decision to take multiple images. Later, using Photoshop's Photomerge command, he sewed together 22 photos to create the final image.
So why are full-circle rainbows so rare? As it's an optical illusion, several factors need to line up for the circle rainbow to come into view. Rainbows form when sunlight is scattered through water droplets in a phenomenon called refraction. This breaks up the light into different colors. In order to see the part of the rainbow on the ground—the other half of the circle—we would need to see water droplets below the horizon. As that's not possible, rainbows almost always appear as arcs.
To see a true full-circle rainbow, you need to be up high. In fact, it's most often pilots that observe the entire circle, as their high altitude and large viewing window are ideal. They can also be viewed from very tall buildings or, in this case, from a drone. In fact, Sidle only saw the arc from his perspective on the ground. It was all thanks to drone technology that he then got a view of something even more special.