As the 44th president's chief photographer, Pete Souza is never far behind President Obama. Now in the National Geographic Special, The President's Photographer: 50 Years in the Oval Office, viewers can follow Souza, and those who came before him, for a behind-the-scenes look at the everyday grit of the American presidency. Offering a chance to see what it's like to cover the most powerful man in the world, for history. The presidential photographer's job is two-fold: one, taking photographs of the president greeting dignitaries, visitors and guests; and two, perhaps more challenging and gratifying: documenting for history every possible aspect of the presidency, both official events, backstage happenings and "off-duty" private moments. "Creating a good photographic archive for history is the most important part of my job, creating this archive that will live on," says Souza. "This is not so much photojournalism as photo-history." Souza and his staff produce up to 20,000 pictures a wee