This searching documentary portrait of the photographer Don McCullin is also, necessarily, a distillation of the most harrowing atrocities witnessed since the Second World War.
McCullin doesn't like being called a war photographer, but the front line is the place he made his name – Cyprus, the Congo, Vietnam, Northern Ireland, Lebanon – and where he has kept going back. (Now aged 77, he recently returned from duty in Syria).
His startling images, some beautiful, many horrible, attest to his bravery, but also to his quick eye and artistic sense of composition: the picture of a shocked Belfast woman cowering in a doorway as soldiers charge past is a marvel of timing. His portrait of a starving albino boy in Biafra is simply appalled, and appalling, an illustration of why his old friend and employer Harold Evans calls him "a conscience with a camera".
McCullin in interview presents a cautious, decent, soft-spoken character, deeply divided about his life's work; on the one hand, his photographs have alerted the world to its "insanity" (a word he keeps using), on the other, he admits his obsessive nature as a "war junkie" effectively destroyed his first marriage.
Perhaps the things he has seen over a lifetime would kill the twinkle in anyone's eye, but it's remarkable all the same how civilised and self-possessed he appears. Directors Jacqui and David Morris have done a good, unfussy job with dynamite material.