Rio 2016: Photographer behind Usain Bolt image explains how he took it

The photographer behind the now-viral image of Usain Bolt smiling during the Olympic 100m final has explained he wasn't even meant to cover the race.

Australian photographer Cameron Spencer was assigned to cover field events when he decided to rush over with minutes to spare and capture the 100m Olympic race.

As the Getty photographer wasn't officially assigned to capture the event, he felt he could risk trying a different blurry effect.

Mr Spencer told Mashable:

I was prepared to take a risk, So I held the camera as steady as I could, holding my breath.

I've shot him enough over the years, He runs really straight.

You have to be calm and collected and keep at the right speed. Sometimes you fail.

Speaking of his record-breaking subject, Mr Spencer said: "That smile sums up his personality, everyone knows he's an entertainer and a showman.

"He's looking at his competitors, going, 'I'm having a good time.'"

"Hundred-meter sprinters are the rock stars, super confident, Bolt's the king of looking relaxed. A larger than life character."

Usain Bolt has now won three consecutive 100m Olympic Gold Medals and is now hunting two more gold medals in the 200m and 4x100m.

If successful, he would end the games having secured nine gold medals across three different Olympics.