I noticed yesterday evening that my room had become a pinhole camera.
The sun shining through the blinds was projecting an unmistakable circle on the opposite wall. I knew that this was an actual projection of the sun, rather than just a diffuse circle of light.
I watched it for a while, then shot this time-lapse of the sun setting through some branches of the tree. Because of how the pinhole camera works, the sun appears to be going up, but that is just because a lens or pinhole will flip the image.
Here is an image looking out the window at the sun behind the tree.
And looking back from where the image was projected, back toward the window.