In 1967, when the renowned landscape photographer Paul Caponigro was living in Dublin, he learned about a herd of white deer in nearby County Wicklow. Intrigued, he asked a man who worked on a large estate there if he could get his dog to chase the deer in and out of a forest.

The late-day Irish light was failing as Mr. Caponigro waited patiently for the deer to show up.

“I thought, ‘Well, the deer are just going to disperse,’” he said in an online video interview with Epson America in 2019. “One deer took the lead, and they all followed. I thought, ‘Unbelievable.’”

He had time to capture them in only one shot, using his large-format Deardorff camera.

The resulting black-and-white photograph shows some two dozen deer in a mesmerizing blur — indistinct, eerie white figures under a canopy of trees.

“Skittish and ghostly on delicate pale legs,” the photographer Amy Miller wrote on Medium in 2016 for a “Photos We Love” feature. “A fleeting moment perhaps in a dream.”

Mr. Caponigro’s son, John Paul, a visual artist and writer, said in an email that his father “would have shot it sharp if he could have,” adding: “The blur is one of those happy accidents. Even when he developed the negative, he wasn’t sure it worked until he printed it.”

His father, he said, “always described it as a gift from the fairies.”