When Red Bull athlete Alex Mason completed a masterfully daring feat—slacklining his way above a 150-foot crevasse in Jackson Hole, Wyoming, during Monday’s total solar eclipse—Keith Ladzinski was there to immortalize it.

In a chilly pseudo-twilight dark enough to see stars, surrounded by the delighted hollering of the huge crowd watching the eclipse from a nearby peak, Mason “just kept walking, almost braille-ing his way across this thing with his feet,” Ladzinski says.

Mason’s stunt is remarkable—and so is Ladzinski’s shot, an in-camera double exposure he was “lucky” to capture.

While scouting the shooting location, a famous ski drop called Corbet’s Couloir, Ladzinski realized that at the moment of totality, the sun would be almost directly overhead—meaning that to