Pete Souza: 'My life as President Obama's official photographer'

US president Barack Obama's official photographer has reflected on almost eight years capturing images of the most powerful man in the world in an interview with Newstalk ZB's Mike Hosking this morning.

Obama will end his presidency in January next year, but thanks to the work of Pete Souza, his ascendancy to the Oval Office is well documented for historians.

• Photos: Moments in the Obama Presidency

Souza told Hosking he shot between 500 and 2000 photos of Obama every day, from functions to meetings to interaction with some of his youngest constituents, and all were kept.

"I have a photo editor who downloads all the photos and captions them. The Presidential Records Act means we save every photo we take. They're all archived, so at end of the administration all are turned over to the National Archives for perpetuity.

"Often I'm the only obvserver in the room. I realise there is going to be a time when 50 years from now, maybe as many as 500 years from now, people are going to be looking through my pictures from different meetings and it's up to me to capture the essence of what took place in that meeting or that event. So I take it very seriously. There's some pressure."

He was a photographer at the Chicago Tribune, and got to know Obama when the rising political star was an Illinois senator.

The tap to join Obama at the White House was "absolutely a dream come true", Souza said.

"It's a once-in-a-lifetime opportunity to have a front row seat to history, to be documenting history with a camera. It's been quite a ride for the last almost eight years."

He tagged along with Obama from the start of the president's working day until Obama returned to the White House residence. He had been in meetings where important discussions occurred and decisions were made, but could not say anything about what he heard.

"I've established a trust with this president. I think that is the main reason I've been successful in being there when important things happen; he trusts me. I think that is probably the most important part of our relationship, is the trust he has with me."

His impact was deliberately minor - he used quiet cameras and did not use flash.

Although he did some planning, he also had to be ready for unexpected moments, Souza said.

"People seem to gravitate to what's called the Situation Room photo, which is when he and his aides were watching the bin Laden raid unfold. That photo has gained notoriety because of the situation itself. But there's so many pictures that I'm proud of that really were not taken when big events were going on. Some of the pictures where he's interacting with little kids, that were sort of unexpected.

"To me it tells you a lot about him as a person and his personality."

He still believed in the power of photography to capture something that video could not.

"It does have a lasting effect. A certain moment in time can sear in your mind, more so than video. I think that's certainly the case with what I do and with the presidency. The singular moments are ones that people remember."