All of the light we receive on Earth comes from the Sun. The light from the Sun is so bright that we cannot directly look at it, even during an eclipse. If we did look at the Sun, the light would damage our eyesight and could lead to blindness. Instead, we need to use equipment to observe the Sun. Some equipment, like hydrogen filters, can be added to telescopes, but others can be cheap and easy to make at school or at home!
In this activity, you will make and use a pinhole camera. You can use this tool to view sources of light without damaging your eyes. Light from a source enters the pinhole and is projected onto the viewing window. You can use it to view the Sun (through the camera at arm’s length) or other light sources like lamps.
When you look through the pinhole camera viewing window, you will notice that the object you are looking at is upside down. This happens because light travels in a straight line from the object, through the hole, and to the screen. Light from the top of the object ends up at the bottom and light from the bottoms ends up at the top! The same happens inside our eyes, but our brain learns to flip these images the right-way-round to make sense of the world.
By the end of this activity you will:
- Have made your own pinhole camera.
- Have made observations of different objects using the camera.
- Understand more about light, its dangers and how it travels.
To complete this activity you will need:
- A shoe box or long cardboard tube
- Scissors or crafting knife
- Ruler
- A light source to look at (e.g., a lamp or the Sun)
- Aluminium foil
- A pin
- Sticky tape
- Thin paper or baking paper
Have a go!
First, make sure you have all the things you need to complete this activity from the list above. Then, read through the safety advice below.
Once you have done that, you are ready to follow the instructions and make your own pinhole camera (there is a PDF of the instructions you can download and print if you prefer).
Safety advice
- Remember, never look directly at the Sun.
- Take care when using the scissors or crafting knife to cut through the card.
Instructions
- If using a shoe box, carefully cut a hole about 3 cm high and 5 cm wide on each side of the box. Make sure that the holes line up with the other so you can see straight through the box. If using a cardboard tube, go straight to Step 2.
- Cover the hole on one side of your ‘camera’ with a piece of tin foil and attach the foil with sticky tape.
- Use a pin to carefully place a single pin-sized hole in the centre of the foil window.
- Cover the other window of your ‘camera’ with the paper.
- Point the pinhole side of your camera towards the light source or Sun.
- View the image by looking at the paper-covered window from at least an arm's distance.
You should be able to see a projection of the object you are looking at on the viewing window. It will appear upside down!
Alternative to steps 4 - 6:
- 4. Leave the other window uncovered
- 5. Place a piece of paper on the floor underneath the camera.
- 6. Point the pinhole to the light source and view the image on the paper on the floor.
What’s going on?
Now that you can view your light source safely, you should be able to see an image of the object you are looking at projected onto the viewing window. The object you are viewing will appear upside down as light travels in straight lines from the object, through the pinhole, and onto the screen. The light from the top of the object travels to the bottom of the screen and vice versa. The light may be coming from the object itself, such as the Sun or a lamp, or will be light reflected by the object from another light source, such as the sunlight being reflected off a tree and into the camera.
If you look at the Sun during a Solar eclipse using a pinhole camera, you will see the Sun change shape as the Moon blocks our view of it. If a planet passes in front of the Sun, you would see a small dark spot moving across the surface. The Sun can also sometimes have dark patches on the surface called sunspots, these are cooler areas on the hot surface of the Sun, if these are large enough you may also see them on your projection.
You can view any object which is creating or reflecting enough light through your pinhole camera, so why not explore how other things appear?!