Pin Hole Theatre

I’m working through more of the SGSI roadmap. Today, I built a pinhole theater using a cardboard box, some duct tape, a white piece of paper, and aluminum foil. The box is big enough to put your head in, the duct tape is to block out all the light at the corners and seams of the box, and the aluminum foil is covering a hole I cut out, which makes it easy to create the pin hole and then change the pinhole size or shape. Across from the pinhole is taped a white piece of paper. When I stick my head in, I just use a sweatshirt to block out the light around my neck, and look at the white paper.

To me, pinhole theatres are more engaging and interactive than pinhole cameras, because it’s like a movie.As you move, what’s showing on the screen changes.

Here are questions that I think can arise in building one and taking it outside:

• How does it work?
• Why is the image “inverted”?
• Why do we need a pinhole?
• Why does the picture get blurry with bigger holes? What makes things blurry in general?
• Why do other shapes (e.g., small triangle) work?

Other things can come up as well. For example, when shining light on the white paper in the theatre, you need a pinhole to show an “image” (technically not an image), BUT with a mirror, a mirror always shows an image without a pinhole. How is a mirror different from a white piece of paper? Doesn’t white reflect all light?

To make sense of these questions, new investigations arise. Including shining light through holes, down tubes, onto paper, shining multiple lights through holes, shining lights through multiple holes, eventually toward figuring out how light gets from sun to objects in the world, to the screen, to your eye, and what happens to the light at each stage.

So, we have mag-lites, then pin hole theatres driving our investigations, and then I think it’s onto eyes.