A Camera Obscura is basically a light-proof box with a small hole called a “pinhole” that lets a little bit of bright sunlight in. Believe it or not, this small hole will project an inverted image on the opposite side of the opening. This is an optical phenomenon called “pinhole image”.
Here is what you’ll need:
- A cardboard box big enough to fit your head in (Amazon boxes anyone?!)
- White Paper
- Paper Plate (or bowl for tracing a circle)
- Packing Tabe (prefer black or brown or duck tape)
- Optional: Markers, paints or other art supplies
- Dark colored sweatshirt
- A Sunny Day. It’s June folks, I hope you’re getting some sun.
- 1-2 hours.
Here’s how you do it.
First, leave the top of the box open and make sure to tape the bottom. You don’t want any light getting in.
Next, poke a small hole with a pencil towards the middle of the bottom. This is the “pinhole”! It should be no wider than a pencil width (and should be 1 to 2 inches from the bottom of the box).
On the opposite side of the pinhole, tape the white paper or papers inside the box. Make it cover the entire side. This is your “Screen”.
Now, turn the box over to the open side. You’re going to make a hold for your head. Put the paper plate (or bowl) in the middle of the box and trace a circle with your pencil. Make sure it’s big enough to fit your head and cut the circle out.
Next look inside your box to find any light leaking through the cardboard and tape the leaks. The only light coming in should be through the pinhole.
Now you can have some fun and decorate the outside to make it a robot head.
Ok, not it’s time. Put on the dark-colored sweatshirt without the arms in the sleeves so it is just around your neck. And, wrap it around your neck to block any light from getting in. You can also use a dark scarf or fabric.
Put your head in the box so the pinhole is behind your head.
Tuck your sweatshirt or scarf into the box so no light leaks in.
Make sure your head isn’t blocking the light coming in through the pinhole.
Stand so the sun is behind you.
AND voila, you will see an image of whateverbehindhind you – only upside down!
Tips: If you can’t see the image, make the pinhole slightly bigger. Make sure there is no other light coming in. Make sure the sun is really shining. Can you sneak a hand in the box and try taking a picture of the projection? Make sure to turn off your flash.
The camera obscura really pre-dates the idea of what a camera is. The term goes back to 1600 but it’s possible that it goes back to prehistoric times. Here are some good images and additional explanation of what is going on: http://www.desertwind.us/blog/2011/06/if-the-box-fits-camera-obscura/