On Sunday, Jamaican sprinter Usain Bolt won the men's 100 meters in Rio, retaining his status as the fastest man in the world.
One photo from the day visually defines the career of this record-breaking athlete. It's from the semifinals.
In it, Bolt is leading the pack. He glances over his left shoulder, grinning, just before he crosses the finish line. His competitors are barely nipping at his heels. Everything below the waist is a blur.
Cameron Spencer, a Getty Images photographer from Australia, captured that moment. "I think there's no greater athlete on the planet at the moment," he tells NPR's Ari Shapiro.
This is the third Summer Olympics at which Spencer has photographed Bolt. "What people love about him, and what photographers love about him as well, is he's such an entertainer," Spencer says. "He's so confident and he plays up to the crowd, and I think when he walks into that stadium, it's electric. And last night was no different."
On how Spencer knew he had the photo
When [Bolt] went past me, you know, this happens in 9 1/2 seconds, and I kind of knew at the 70-meter mark he was going to probably be ahead of the rest. ... When he passed me around the 70-meter mark, I was infield and I sort of panned my camera with him ... it wasn't till I looked at the back of my camera — firstly hoping that something was sharp and that I'd captured it — I then realized he's almost looking straight at me and he had the big grin going, and the eyes, and I knew that it was special once I saw that.
On the scene in the Olympic stadium
When there's that many people there to witness greatness and the hush goes over the crowd before that starter's gun goes off, it's spine-tingling stuff. ... He's got his famous [lightning] pose he always does, but he's done that a million times. And I think last night, giving that cheeky grin to the other competitors was something that made it different.
On what it's like to photograph Bolt
I've never met him personally, but I have done a lot of running around trying to chase him, last night included. ... I did the lap of honor with him. ... It's that balancing act between interaction and also being a fly on the wall, letting him run around — and you also have to avoid tripping over everything around the stadium because you're also running backwards in front of him.