Join our 4-H teens as they learn about light and vision!
What are we learning about today?
Have you ever wondered how a camera actually works – or how your eyes see the world around you? Well, guess what? You can make one too!
A "camera obscura" is a dark space with one tiny hole that lets light in. That light projects an upside-down, backward image onto a screen inside the tube or box – just like how light enters your eyes and hits the back of your retina.
To help understand a camera obscura better, think about how your eyes help you see. Take a moment to look at something around you. You can see it because light rays from either the sun or the lighting around you are shining on the object and reflecting into your eye. Then those light rays make a projection or picture on the back of your eye in the light-sensitive area called the retina. A camera obscura works in a very similar way.
Now, let's make one!
What do you need?
- 1 paper towel tube (or two toilet paper tubes)
- Aluminum foil
- Tracing paper, wax paper, or parchment paper
- Tape
- Scissors
- Pushpin
- Dark-colored construction paper for decorating and blocking out extra light
Try it yourself!
- Get the tube ready – The tube makes sure no extra light gets in so you've got a sharp image.
- If you're using a paper towel tube, cut it into two parts – one short and one long.
- If you're using two toilet paper tubes, just cut one in half and keep one piece.
- Make the screen – The screen projects an upside-down image of whatever you're pointing the camera at.
- Cut a small square of tracing paper and tape it tightly over one end of the longer tube.
- This is your screen where the image will appear.
- Make the pinhole – This allows the light to enter the camera and make the image.
- Cut a square of aluminum foil and tape it over one end of the shorter tube. Then gently poke one small hole in the center using your pushpin. This is your lens!
- Put it all together!
- Tape the two tubes together so the tracing paper is in the middle, and aluminum foil is on the end.
- Wrap the whole thing in dark construction paper to keep extra light out – but leave the ends open!
- We've got a camera – Let's test it out!
- Go outside or find a bright area indoors.
- Point the foil/pinhole end toward something light – like a window, a lamp, or a bright object.
- Close one eye, hold the open end up to the other, and look at the tracing paper screen inside.
- Give your eyes a few seconds to adjust.
- What do you see?
- An upside-down image! That's light in action – traveling through the pinhole and projecting the world onto your screen.
Open and print the supply and test list for yourself!
Want to learn more?