When it comes to defining Ellen Kuras, it's simplest just to call her a filmmaker. The bulk of her work is as director of photography for many of the great film directors of our time. She also makes commercials. Last year, her film "The Betrayal" received a nomination for best documentary Oscar. Kuras will speak about her work Saturday night at the Walker Art Center in Minneapolis. She says the different facets of what she does are very much intertwined. Ellen Kuras went to college to study Egyptology and anthropology. To hear her tell it, the path to becoming a cinematographer was a natural progression. "Basically I realized I was interested in people and history, and how people relate to each other and culture. And it was that that led me to an interest in documentary filmmaking," Kuras said. "I have a very strong sense of the political. And I thought, I want to make films that move people, I want people to be educated about the nature of the world, or about stories about people." Kuras started work on a film about a family of Laotian refugees living in New York. Like the Hmong, they fled Laos after helping the U.S. military in the so-called secret war in their country. Kuras directed the film about their struggles in America. She knew it was a great story. Yet as she reviewed the material her crew shot, she became uneasy. The footage was technically great, but she felt something was missing.