"I don't know that she would like it," he said of the way he spends his days here, which often begin at 4 or 5 in the morning. "If you are not obsessed, you wouldn't have much fun."
In fact, besides the hours he spends working on the website from his home in an industrial neighborhood outside Stuttgart, Schall's life in Germany has little to do with his life in L.A. He purposefully tries to keep them separate -- guarding his intimate relationship with Southern California like a treasure. Most of his friends don't know anything about his role as the greatest L.A. architecture nut.
"I don't talk about it much," he said. "It's something very special. It's not like football or what the other guys do."
SCHALL is an unlikely example of the ultimate L.A. tourist. For starters, he hates vacation. He said he takes time off from work, mostly doing maintenance on oil platforms in the North Sea, grudgingly because his boss forces him, really.
But L.A.'s pull is strong.
All the time, Schall said, "there are people writing e-mails, saying, 'I have a nice building here.' Then I find the architect's name and see that there are five other buildings by him. Then it starts, again and again."
People are generally receptive to his photographic musings. (Though after 9/11, he was stopped repeatedly by police while photographing buildings. "They asked, 'Are you a terrorist?' I responded, 'Tourist.' They said, 'OK, have fun.' But it was really strange, you know?")
The constantly evolving face of downtown Los Angeles, which Schall has witnessed over the last 11 years, has been both a comfort and a challenge to the photographer.
Hundreds of years of European history have taught him that "you can't prevent the city from changing."
But as the city center has begun to transform from a long-moribund office hub to a thriving residential neighborhood, Schall finds that his to-do list is getting longer. A new coat of paint does not warrant a new photo, he said. But when a building's architectural details, long hidden, are revealed by a renovation, he goes out of the way to document them.
Near 5th Street and Broadway, Schall pointed at a building that was midway through a rehab. Already, intricate cornices just above the ground floor had been revealed, as well as delicate leafy decorations farther up the edifice.
"Last year there was scaffolding on that building. I think I'll make a picture of it now," he said as he scurried into traffic to get the shot.
At the corner of 11th and Main streets, Schall noticed a tall brick structure with graffiti on its windows and storage on the upper floors. The building, home to a couple of wholesale accessories stores, was something that most people would pass by without noticing, let alone admire.
But Schall crossed the street and circled the building, almost willing it to tell him its story. Above the entrance, he noticed a clue: a few words etched in stone, partly covered by a lowered ceiling and a security gate: M. HARRIS BU.
"Now we've found it," he crowed.
Schall crouched down, pulling a special green notebook out of the pockets of his khaki jeans. He noted the building's location, the words on the sign, and drew a rough map of the corner. It was enough information to go on.
He replaced the pen in the notebook's spine and stood up.
"Maybe we should make a picture now?" he asked in a sing-song voice, light with his German accent, and walked across the street to a position kittycorner from the building.
There, Schall waited patiently for the golden moment that he says comes every 15 minutes or so: an instant when even along a busy street the building can be photographed without cars or buses in the way.
It is a moment worth waiting for, he said, when the building can show itself off in proper splendor. "If you do it, you show some respect. You show you are not in a rush. It's some respect for the building, I think."
Then the traffic subsided, and Schall stepped out into the street. He pointed his camera, a digital Canon 300D with wide-angle lens, and snapped.
When he returned to Germany, Schall searched the archives of The Times, available through the Los Angeles Public Library's website. (After years of trying, he scored a library card on this trip, allowing him free access to the site.)
He would learn that the 10-story structure was built in 1923 and touted by an ad in the newspaper at the time as being "in the heart of Los Angeles' rapid growth." He posted the building's picture at you-are-here.com along with a simple caption: "Morris Harris' Union Manufacturing Co. Building 1923 Harwood Hewitt."
"I don't know a lot about architecture," he said. "What I like is the story of who was in the building."