Mysterious Blue Crescent Decoding in Many Photos of Total Eclipse

On August 21, Americans had the opportunity to admire the total solar eclipse of "one hundred years". In the moment the Sun disappeared in the sky of America, many people were fortunate to capture one of the most remarkable astronomical phenomena this year.

Key Facts About Blue Crescent

A photo of an eclipse near the Capitol (left) and a Flatiron building (right) with a smartphone with a mysterious blue crescent.(Photo: Emily Cohn.)

According to experts, this blue crescent is actually an illusion phenomenon that appears due to the "Lens Flare" effect of the camera and smartphone. When the camera is shooting under strong light conditions this effect will occur because the lens reflects part of the light.

Why Blue Crescent Matters

A photo taken by camera eclipse often has the appearance of a blue crescent.(Photo: Rebecca Harrington.)

Because the intensity of the light is so strong, the Sun images when eclipses are taken with smartphones and regular cameras are often dazzling and not sharp.

Typically, the "Lens Flare" effect appears in a circle or small dots. But when the solar eclipse occurred, because the Sun was partially obscured by the Moon, the light intensity was also weaker, causing blue crescent images to appear on digital images.

In this eclipse photo, three crescent images appear.(Photo: Rebecca Harrington.)