I worked with Megan on her camera obscura project at Bournemouth beach. We had to cover the windows of a beach hut and then we cut a hole in a central position in the cardboard we used so that an upside down projection appears on the back wall of the hut. In order to achieve a sharper image we also measured the distance from window to wall and bought a cheap lens that matches the focal length of this, which brings the projection into focus.