In the same camera-making class mentioned in my last post, Peter Renn turned the room itself into a camera obscura (a dark room) with a large single lens you can see in the first image. It has a focal length of something between 1000 and 2000mm, casting a massive image circle. In the first picture above you can see the lens and part of the image on the floor. In the next couple of images you can see different parts of the image transmissively through a large, hand-held roll of tracing paper bringing different parts of the image into focus by moving back and forth. Next we used a large foam stage flat, and I took pictures of different parts of the image projected onto it. Click any of the pictures to see them all full-sized.