1600 Pennsylvania Avenue is normally not a hospitable venue for return engagements.

From 1983 until January of 1989, photographer Pete Souza served as a member of the White House photographic staff documenting the presidency of Ronald Reagan. The "Gipper," as he was known, was 50 years older than the awestruck photojournalist. Pete's photographs from that time were published in his book "Images of Greatness: An Intimate Look at the Presidency of Ronald Reagan," which also became a feature on The Digital Journalist. When Reagan died, his widow Nancy asked Pete to do the official photography of the final services in Washington.

Now, at 54, Pete Souza is back at the White House as President Barack Obama's personal photographer.

Souza had first met Obama when he was sworn in as a senator from Illinois from 2005 – 2006, while Souza was the Washington bureau photographer for the Chicago Tribune. He then traveled extensively with the Democratic presidential candidate. They came to know and like each other, except this time the age gap between photographer and subject was reversed.

And with that age came a deep understanding of how the White House worked, which proved useful for both parties.

Being appointed as the official presidential photographer is not only a great honor, but also an enormous responsibility. The job carries a full presidential commission saying "having the full faith and confidence of the president."

Although Souza has hired a staff to help him, including photographer Chuck Kennedy and former Time acting picture editor Alice Gabriner, the days are very long. The photographer becomes "the shadow" of the president. Souza is always close at hand, whether in the Oval Office, the residence, or at his side on foreign trips.

Photojournalist PF Bentley, who remembers Souza from the Reagan years, says, "Pete is always an island of calm in a storm. He is a quiet and unassuming guy who knows his way around the White House and Washington, and on top of that, is a genuinely nice guy."

Souza understood what he was getting himself into when he accepted the job. "I knew what to expect," he says. "I also run the office, so was able to hire the best people to complement what I do."

Asked about his relationship with the president, Souza says, "I get along with him great. There are no ground rules, per se. I use my instincts on which meetings I can stay in for the entire time, and which ones I leave after only a few minutes."

David Hume Kennerly, who filled the same spot under President Gerald Ford, added, "Not only does Pete have great knowledge about the White House but he is unintimidated by holding that job. He also understands the importance of helping outside photographers to get access to the president. You couldn't find a better guy for the job."

In an interview with ABC's Jake Tapper, Souza put it all into perspective:

"My relationship with the president [-elect] is a professional relationship. I'm not his friend; I don't look at myself as his friend. I'm there to document for history and I think he understands that role … it's something that I have to be conscious of and I'll probably be explaining to his aides over the years the importance of documenting things even when they're not going well. That in the long run is good for the American people -- to see pictures in all kinds of situations involving the president. And again -- maybe not right away, maybe 10 years from now, maybe 50 years from now -- I really want to impress upon them the need to document the presidency for history with photographs."