Safety Note
Please always wear very strong / dark sunglasses for this activity, ensuring adequate UV protection for your eyes. Never ever look directly at the sun or the focused light from the magnifying glass to protect your eyesight. After using the magnifying glass, put it back into a container or out of the sunlight, as it could cause a fire.
Activity Guide
- Find an outdoor area with direct sunlight.
- Take the small board and use a pencil to draw or write or draw something of your choice on its surface.
- Wear strong sunglasses with good UV protection to protect your eyes during the activity.
- Hold the magnifying glass and orient it towards the sun, adjusting its angle until you find the point where the sunrays are most concentrated on your surface to be engraved. You will see the sunrays as a small, very bright spot with clear-cut borders. Then you have the maximum concentration and highest temperature.
- Soon, you will notice that the surface slightly burns and turns black in this focal point.
- "Draw" the lines of your sketch on the surface you marked in pencil with the focused beam of light coming out of the magnifying glass. Be patient and careful in creating your art.
- When you're done, remove the magnifying glasses from the sunlight, put them in the shadow and/or cover them.
Exploring the Science Behind
Through a lens like a magnifying glass, sunlight can be focused to a point without being reflected. This point is called the focus or focal point. At this point, all the energy from sunlight is concentrated, allowing the surface, such as wood, to be burned, creating your artwork.
The magnifying glass, like any lens, does not increase the energy of the sun's rays, but it does make them come together so that they are concentrated at one point: the focus or focal point. All the energy is concentrated in it, which allows the surface to be burned, in this case, the wood.
Did you know
- On a sunny day, you can even start a fire using the same technique of focusing sunlight with a lens.
- Famous Filipino artist Jordan Mang-osan creates stunning works of art on wood using only a magnifying glass and the sun's rays.
Reflection Questions
- What is the difference between using the magnifying glass technique and using an electric tool that has similar effects (electric pyrography pen) for art?
- What are the advantages of using sunlight when making art this way?
- If you try out the experiment with and without pencil lines, you will see that without, it takes much longer to start burning. Why is this so? Why does the pencil line burn faster than the wood/cardboard without?
- How do you feel about contributing to the planet by creating art in an eco-friendly manner?
Additional activities
Discuss how lenses, like magnifying glasses or parabolic mirrors, concentrate sunlight onto the cooking post in a parabolic solar cooker .
Discuss also the question of the ‘moving focal point’ due to the apparent movement of the sun and the use of ‘solar trackers’ for instance in solar thermal power plants.
