The University of Wisconsin-Madison holds an annual Cool Science Images contest, inviting campus researchers to submit interesting photos and videos.
"Using a pinhole camera made of an aluminum can, duct tape and photosensitive paper and positioning the device atop Sterling Hall from winter solstice to summer solstice, yields a symmetric chart of the sun's path across the sky. The lowest arc was the sun's winter solstice trajectory and the highest arc was the sun's path at summer solstice. Gaps between the arcs are days of overcast weather.I'm amazed that the paper isn't totally bleached-out during a six-month exposure. The sensitivity of the paper must be extremely low. Very cool.