Award-winning photographer, artist and filmmaker Tomas van Houtryve was selected to visually document the devastation wrought by the massive blaze that ripped through Paris's Notre-Dame Cathedral four years ago. Over the course of 12 months, he enjoyed rare access to the monument and the teams assigned to painstakingly restore it to its former glory. His exhibition "Notre Dame: Rebuilding an Icon" can now be seen outside the cathedral, where it will remain until next summer. He joined us for Perspective.