AP photographer Gregory Bull discusses how he captured iconic image of Olympic gymnast Gabby Douglas

It's one of the most iconic images of the 2012 London Olympic Games, so far: a shot of U.S. gymnast Gabby Douglas leaping high above the balance beam, on her way to winning the all-around gold medal for Women's Gymnastics.

The image was shot by AP Photographer Gregory Bull and it's turned up on thousands of newspaper front pages and millions of websites around the world.

In the video at the bottom of this post, Bull talks about how he captured the shot (shown as a cropped, partial frame grab below), saying he had seen Douglas do her balance beam routine during the Olympic trials and knew the moment he wanted to capture.

"There's this moment where she just launches," Bull says, adding that he was shooting "in sort of a half crouch" so he could use the balance beam to hide the television cameras in the background.

Despite the preparation and zooming all the way out "to include a lot of extra space," he actually thought he had missed the shot.

"When it happened, I thought I cropped her arm off," Bulls says. "She went higher than I thought she would and I just went 'oh man.' I wasn't expecting it to be that high."

Because of the way he works for the AP -- shooting and then handing off his memory cards to photo editors -- Bull didn't get to see his Gabby Douglas images until two hours after the medal ceremony.

It was only then he knew he had captured an important moment in time.