National Geographic has published some amazing photographs over the years, but for every great shot the magazine prints, there are probably thousands that didn't make the cut.

Now you can see just how National Geographic photographers got those incredible photos in a new iPad app, the 50 Greatest Photographs of National Geographic ($4.99).
The app not only contains the 50 iconic photos but also the stories behind them. The photographers behind the pictures have contributed their stories, often on video, sharing their journeys and the months or even years they spent waiting for that perfect image to appear in front of the lens. You'll also see the near misses — the photos that didn't quite achieve the brilliance for which the magazine is noted.
The photos, most of which are famous, were worth the wait. As the New York Times reports, photographer Paul Nicklen waited nearly a decade to get his photo of a polar bear swimming underwater, and when he did get it, it was just a matter of opportunity: "It was a shot he had thought about for almost 10 years, but when the opportunity presented itself, he just stuck a submersible camera below the water’s surface and blindly fired away."
The app comes with a promotional video from Canon (as the Times writes, "C’mon guys, either charge or make it ad supported, but not both."), but you can skip it if you hit the right buttons quickly enough.
The app is available through the iTunes store.