DIY published instructions for a diy solar eclipse viewer made from a cereal box, paper, tin foil, a pen, sellotape, drawing pins and scissors. The setup lets people watch today's eclipse indirectly, a practical option for anyone who does not have official eclipse glasses.
The build is simple: trace the cereal box bottom onto white paper, cut it out and tape it inside the box. Then cut a square on the top left and top right of the lid, seal the middle section, cover the left opening with tin foil, and make a tiny pinhole in the foil.
UK eclipse reaches 90-96%
From British soil, today's eclipse is set to be almost total, with 90-96% of the sun obscured depending on location. The UK will not see another total solar eclipse until 2090, and the last total eclipse took place 27 years ago, which explains why a low-cost box projector is being offered as a simple fallback for households that want to observe it.
At the time of the eclipse, the sun should be behind you, the bottom of the box should point toward the ground, and the box should be angled so sunlight travels through the pinhole. You then look into the uncovered corner to see the eclipse safely and indirectly, using the cardboard box as a basic projector rather than staring at the sun itself.
Tin foil pinhole method
The left top corner is covered with tin foil because the pinhole is the only entry point for light. The right top corner stays open so your eye can receive the image formed inside the box, while the sealed middle section keeps stray light from washing out the projection.
That setup is the key practical step for readers who want a quick home build before the eclipse reaches its peak. The article gives a home method, but it also warns that looking directly at the sun without official eclipse glasses can cause permanent damage to the retina, and an unfiltered phone camera pointed at the sun for more than a couple of seconds can damage the internal sensor.
Direct sun exposure risk
The viewer is meant as an indirect viewing tool, not a substitute for safety rules. It offers a way to follow the eclipse with household materials, but it does not change the basic risk that direct viewing without proper protection can harm eyes and, in the case of a phone, the camera hardware.
For anyone preparing at home, the useful part is the sequence: build the box, face away from the sun, angle the viewer, and watch the image rather than the sun itself. How the homemade projector compares with official eclipse glasses is not explained, but the instructions do give readers a way to see today's event without needing to improvise with unsafe filters.
