The editors of Smithsonian magazine have just announced the 50 finalists in their 9th annual photo contest. They've kindly allowed me to share several of the final contenders below, including some amazing images from each of the competition's five categories: Americana, The Natural World, People, Altered Images, and Travel. Be sure to visit the contest page at Smithsonian.com to see all the finalists and to vote for this year's Reader's Choice winner.