Andrew Crommelin and Charles Davidson took the photograph that proved Einstein right about the universe in 1919. So why does history only remember Arthur Eddington's name?

A publicity still from the BBC drama Einstein and Eddington shows David Tennant as Eddington and Andy Serkis as Einstein, standing together in period suits in front of a chalkboard.

Almost every photographer has watched someone else get the credit for a picture they actually took.

Usually it's a minor issue: a mistyped byline, a client who thanks the wrong assistant. But in May 1919, it happened on a scale that reshaped our understanding of the entire universe – and the person who ended up with the glory wasn't the one holding the camera that mattered.