Here’s one photo you probably won’t find on the White House’s “Photo of the Day” feature: President Barack Obama closely examining first dog Bo Obama’s um, droppings.

But back during President Lyndon B. Johnson’s time at 1600 Pennsylvania Ave., a similar scene was captured by White House photographer Yoichi Okamoto. (Johnson, mind you, was checking to see if one of his dogs had worms.)

Okamoto set the standard for White House photographers, according to author John Bredar, who chronicles the history of White House photogs in the new National Geographic book “The President’s Photographer: Fifty Years Inside the Oval Office.”

Most of the featured photos show presidents during pivotal moments in history, while others show their softer sides. Rare are photos of presidents examining dog doo, Bredar admits.

“Oh my God, I can’t believe that. One, he’s able to take the photo,” he jokes. “And two, LBJ would be sincerely curious whether this dog had worms.”

National Geographic also produced a documentary tied to the book, set to air Nov. 24 on PBS. The special mostly trails current White House photographer Pete Souza as he snaps shots of Obama.

Bredar, who serves as executive producer, admits it was tricky persuading Souza to participate.

“They are not interested in being the focus. It’s bad for their job,” Bredar says of White House photogs. “These are guys who spend a lot of time figuring out how to be invisible.”