His work focuses in feature stories, reportage and documentary based on religious communities, human nature and conflicts, the later being his main focus for the past years. Contreras has studied Philosophy and Photography, conducting research for many years and dedicating himself to photography professionally for three. Contreras is currently covering the ongoing civil war in Syria. His work has been published in newspapers and magazines all over the world, among others in TIME, the Guardian, the Times, the New York Times, der Spiegel, National Geographic, the Telegraph, the Washington Post, Newsweek, Wall Street Journal, L’ Espresso among others. Contreras is currently represented by Associated Press and Polaris Images.He is available for assignments.