‘Salt of the Earth' a stunning documentary

There are thousands of them, grim-faced men caked in mud and dirt, crawling in and out of an enormous hole in the ground like ants, carrying sacks on their backs as they march precariously up the sides of the chasm. The black and white pictures that fill the screen at the start of “The Salt of the Earth” seem impossible, a work of science fiction and special effects. But then we hear the voice of the man who took them, the renowned Brazilian photographer Sebastião Salgado, and he tells us how each man was there out of his own volition, not by force or under orders, and each one is hoping his bag will contain nuggets of gold from the mine, an enormous chasm in the earth that looks otherwordly, surreal.

The Oscar-nominated documentary “The Salt of the Earth,” which was co-directed by Wim Wenders and Salgado’s son Juliano Ribeiro, is a risky proposition. “A film about the life of a photographer?” Wenders himself asks early on, wondering if there will be enough here to sustain a feature-length movie. After all, Salgado’s socially conscious work has already traveled the world, being exhibited in museums and galleries and collected in mammoth books such as Workers: Archaeology of the Industrial Age, Sahel: The End of the Road and Migrations. The photos - depicting famine, poverty, war, nature and disasters - are so powerful and harrowing they don’t need explanation.

But Wenders, an artist who is equally comfortable making feature films (“Wings of Desire,” “Paris, Texas”) as he is directing documentaries (“Buena Vista Social Club,” “Pina”), becomes intrigued by Salgado. He wants to know what drives the photographer and why his work has left such a deep mark on him. And as Salgado recounts his career for us and tells us about his extraordinary journeys, from the burning oil fields in Kuwait to ravaged African regions, we begin to understand why he was driven to travel to more than 100 countries and spend years away from his wife and children in order to bring light into parts of the world that lived under shadow and capture the lives of the poor and downtrodden who live there (“The power of the portrait lives in that fraction of a second when you capture a person’s life,” he explains, a talent he possesses with no apparent limits.).

Many of Salgado’s photos, especially the ones showing starving people in Northern Ethiopia and refugees from war-torn Rwanda, are beautiful yet difficult to look at, often capturing a kind of unimaginable horror that is difficult to even think about. Salgado’s work took a deep toll on him: After his last visit to Rwanda, he lost hope in humanity. “What is there left for one to do,” he asks, “after you’ve stared into the heart of darkness and decided mankind doesn’t deserve to exist?”

The answer to that question - and the reason why Salgado continues to work today - is best left unrevealed for those unfamiliar with his extraordinary story. The “Salt of the Earth” is a celebration of the power of art to change the world, as well as an exploration of the considerable toll gifted artists sometimes pay for their talents, and their courage to push forward regardless.