Joe McNally (@joemcnallyphoto) has been recognized as one of the best photographers in the world. He's contributed to National Geographic for more than 25 years, captured images on 70+ countries around the world, and has been awarded four World Press Photos for his work. We chat about what it takes to hold a successful photography career that spans decades, the “democracy of digital,” and one of his most notable works: capturing the Faces of Ground Zero, following the tragedy of September 11th.