Over Christmas, while staying with my inlaws in New Mexico, I found in the bathroom library an old issue of National Geographic from May 2011. Photographer Abelardo Morell shot rooms that had been “decorated” using a camera obscura. Basically, he covered a room’s windows and allowed in only a pinprick of light, letting the image enter the room and “project” against the far wall. He sometimes used a prism to turn the image right side up.
Here is his shot of the Piazza San Marco, projected onto an office wall:
Here’s the text of the article, explaining the history of the camera obscura and Morell’s technique:
My first time seeing a camera obscura was just outside the Cliff House in San Francisco. You can peer into the camera’s dish and see the ocean waves hitting the shore or gulls flying overhead. It moves! When seeing a camera obscura image live, it’s not static like a photograph. How wonderful that Morell chose to bring us this vision of Venice!