How to make pinhole projector for solar eclipse as stocks run low on special glasses

Solar eclipse: How to make pinhole projector at home as stocks run low on special glasses

A partial solar eclipse - with around 90 to 96% coverage - will be visible from the UK on Wednesday.

A partial solar eclipse will be visible across the UK on Wednesday August 12, with around 90 to 96% of the Sun covered by the Moon.

During late afternoon on Wednesday, the Moon and the Sun will gradually move closer together in the sky.

After 6pm (timings vary slightly for different parts of the UK), ‘first contact’ - when the Moon first covers part of the Sun - will occur. The Moon will move slowly in front of the Sun until roughly 90% of the Sun is covered (the eclipse’s maximum). This will be after 7pm, again timings differ slightly depending on where in the UK you are.

A woman uses two sheets of paper as the Sun is obscured by the Moon during a partial solar eclipse at Skegness seafront in Lincolnshire, north England on 20 March 2015.

However, for many it’s proving difficult to secure eclipse glasses, which have specially designed filters, as stocks run low.

Here, we’ve detailed why it’s important to watch a solar eclipse safely and how to make a pinhole viewer.

Watch our 60-second solar eclipse video explainer in the player above, detailing what a solar eclipse is, when to see it this week and how to view it safely.

Why it’s important to watch a solar eclipse safely

The Sun appears dimmer than usual during an eclipse. The reduced brightness of the Sun can override the body's natural reflex to look away - allowing intense sunlight to reach and damage the retina. The damage happens without causing pain so you may not realise it’s occurring until too late.

Why sunglasses are not adequate protection for watching a solar eclipse

Ordinary sunglasses - no matter how dark - don’t provide adequate protection for watching a solar eclipse. Sunglasses reduce glare, making it feel more comfortable to look at the Sun for longer, while still allowing harmful solar radiation to reach the retina. Never use regular sunglasses to look at the Sun during an eclipse.

How to watch a solar eclipse safely

There are two safe ways to watch a solar eclipse - specialist eclipse viewers or indirect viewing methods.

Specialist eclipse viewers

If using eclipse glasses or handheld solar viewers, make sure they are genuine with specially designed filters that meet the international safety standard ISO 12312-2:2015(E). Don’t use the product if you’re unsure it’s certified or if the lenses are scratched, torn or damaged.

Indirect viewing methods - how to make a pinhole projector

You can watch the eclipse indirectly by using a pinhole projector, which allows you to see the eclipse by projecting the Sun’s light, and the bite being taken out of it, onto another surface. This can be done from home by using paper, a colander or tree leaves.

To use the paper method, you should make a small hole in one piece of paper and hold it above another piece of paper to see the shadow being cast on the Sun replicated in miniature. To use a colander, hold it up and look at its shadow. With the tree leaves method, the gaps between leaves are natural pinhole projectors - look at the shadows cast by leaves on the ground.