The artist Ben Johnson has painted every building on the Liverpool skyline in one picture. He painted all 30,000 tiles of the Dome of the Rock, each with seven layers of paint. And he’s spent the equivalent of 17 years on one artwork. He is, he admits, a bit obsessive.

His work has been shown at London’s National Gallery and now for the first time, his life’s work is on display in a retrospective at Southampton City Art Gallery.

He told BBC News the story of a traumatic and chaotic childhood that lies behind these quiet, painstaking paintings.

Video journalist: Dan Curtis.