Classroom-Sized Camera Obscura

I thought this was too cool not to share. The high school teacher completely blacked out his room by sealing up all the cracks along the doors and windows. He then cut a small hole into the cardboard covering the window and placed a large sheet that hung from the ceiling. After we turned off the lights and sat in the dark for a short period of time, we began to see a projection on the sheet of what was outside the window. We even sent students outside to walk around and they could be seen being projected onto the sheet.

If you look closely, you can see the upside down pine trees.