“We were in this room for about 40 minutes while the raid was playing out,” Souza said. “The interesting thing to me was that some of the most powerful people in the federal government were in this room, and there was nothing they could do but watch. I think that accounts for the anxiety you see on everyone’s faces.”

Other photos reveal quiet moments in the White House. At right, President Reagan works alone in the Oval Office.

Souza also produced a book based on his time with Reagan, "Unguarded Moments: Behind the Scenes Photographs of President Reagan," featuring photos like this one.

“I set up a remote camera above the windows to capture this image in 1988,” Souza recalled.

Though technology has drastically changed since his time in the Reagan White House – Souza cites the advent of digital photography and social media among many broad changes – he said his mission remained the same.

With all of his White House photos, he strove to give the public a closer look at the presidency than news photos can typically provide.

“I try to capture the accurate mood and emotion of what is taking place, hopefully in a somewhat artistic way, without interfering with what is taking place,” he said.

“It’s a bit more intimate than what you would see from other photos in the news.”

This photo is a good example of the more informal moments Souza was privy to. Jacob Philadelphia, a 5-year-old boy whose father was leaving his post on President Obama’s national security staff, was in the Oval Office for a farewell meeting and family photo-op.

“Jacob told the president that his friends had said his haircut was just like the president’s, so the president bent over and let Jacob touch his head,” Souza recalled.

The photo quickly became popular on social media, and remains one of the best-known images from Souza’s tenure in the White House.

“I think it resonated with a lot of people, this moment of a young African-American boy touching the head of a president of the United States who looks like him,” Souza said. “I also think it tells you something about Barack Obama and the type of person he is.”

Of course, Souza also witnessed less light-hearted interactions, like this 2014 conversation with Russian President Vladimir Putin in Normandy, France, shown at right.

The photo was taken at a luncheon for heads of state amid the contentious global debate over Russia’s repeated incursions into Ukrainian territory.

“This was not a scheduled meeting,” Souza said. The two leaders stepped aside after the luncheon to talk, in what Souza recalled as a tense conversation.

“I like the body language shown in the photo,” he said. Despite the language barrier – there is an interpreter standing behind the two – “you almost get the sense that the president’s body language is a tongue of its own, and clearly understood by Putin.”

The last photo that Souza shared depicts Obama not just as a president and a man, but as a father enjoying playing in the snow with his daughters.

Malia and Sasha Obama were 10 and 7 years old, respectively, when their father took office, and they spent most of their adolescence in the White House.

“This was taken during a big snowstorm in 2010, when the president came outside and played in the Rose Garden with the girls,” Souza said. “Part of what I tried to do as the White House photographer was to show the president as a father and to share a bit of what he was like as a human being, not just as a president.”