5 Ways to View a Solar Eclipse Safely
- 22nd Mar 2025
- Author: Emma Mosley
Here in the UK, we are occasionally treated to a spectacular solar eclipse in our skies. This happens when the Moon comes between the Earth and the Sun, blocking out the light from the Sun. Find out why eclipses happen and what the different types are here.
The Sun is really bright. Considering it emits a lot of light that’s not much of a surprise. But when it starts to darken during an eclipse, we naturally want to look up with our eyes. Our natural reflex to protect our eyes by moving away or squinting doesn’t happen. Instead, whilst we are looking, light from the Sun enters our eyes, including Ultraviolet (UV) and Infrared (IR) light. UV light is the stuff that gives us sunburns and IR light is given out from heat sources. If too much of these enters our eyes, it can permanently damage our eyesight.
Only during the very brief moments of complete totality during a total solar eclipse could we look with our eyes. During the phases on either side of complete totality and during other solar eclipses, we need to protect our eyes. This makes viewing a solar eclipse quite difficult.
Thankfully the solution is really easy and whatever you do, do not look up at the Sun without protection!
Here are our top 5 ways to view a solar eclipse safely:
1. Buy a pair of eclipse glasses
Make sure these glasses are eclipse glasses and not your normal sunglasses as there is a big difference. Eclipse glasses have filters on their lenses which are made to a much higher standard, they reduce visible sunlight to safe and comfortable viewing level and also block out most of the harmful UV and IR rays from the Sun. Make sure the glasses have ISO 12312-2 which is set out by the International Organisation for Standardisation (ISO). This declares that they conform to the international safety standard and you just look at the label or any writing on the glasses for this number.
Before using these glasses make sure there are no scratches, tears or damage to the filter on the lenses. The damage could make the lens filter ineffective and damage your eyes when used.
Put the eclipse glasses on before looking up and make sure you are looking away from the Sun before taking them off. Don’t forget to supervise children when using them.
2. Create your own pinhole camera
What is a pinhole camera?
These camera use a pinhole which is a very small hole usually about 0.1 – 1 mm wide. This tiny hole, for example in a piece of paper, is small enough to diffract the light rays when it passes through to produce an image on the other side. It’s similar to how our eyes work and gives an upside down image.
When we use a pinhole to create an image inside a box then we call this a pinhole camera. If the image produced is hitting the ground then we call this a pinhole projector.
By using a pinhole camera and a pinhole projector, we can view an eclipse safely as we don’t look at the Sun directly.
Where can I get a pinhole camera?
You can get your crafty fingers out and make your very own pinhole camera. There are lots of ways to make one as all you need is a box, a viewing hole and a tiny pinhole at the top.
One easy method is to use a cardboard box, like the one you get in a delivery:
- Make sure the bottom is sealed with a piece of white paper to fill the bottom.
- Cut off or tape to the sides the smaller flaps on the top opening out of the way.
- Have one of the large opening flaps open and the other closed, use tape to hold both in place.
- With the closed side, poke one or a few small holes through the cardboard. You can use a pin or a sharp pencil, with parental supervision.
- Take it outside into the sunlight and you can view an image of the Sun at the bottom of the box. If the image is not clear, make more holes of different sizes until the image is clear.
NASA have their own template for you here to print off and build at home. It is based on the SunRISE CubeSats currently in orbit around the Sun. All you need is an A4 sheet of paper, scissors, glue/tape, pin, and a printer that can print double sided.
3. Raid the kitchen for a pinhole projector!
Got a spare colander? Apparently you normally use a colander for straining vegetables (who knew?!), but they also make a very handy eclipse viewer.
By holding the colander above the ground, pointed towards the Sun, all the holes act like pinhole projectors. The sunlight passes through, becoming diffracted, and when it is focused enough, we see lots of mini eclipses!
To help to see these clearly, place a white sheet onto the ground or a piece of white paper. Then lift the colander up until you can see lots of mini eclipses.
You can also get this effect by:
- crisscrossing your fingers to make small holes
- holding a piece of card with a pinhole in the middle
- using a pizza tray
Using a pinhole projector is very easy, just don’t forget the pizza!
4. Set up an optical projector
We can use lenses to refract the light to focus an image of the Sun. You can use your telescope and binoculars to do this. We recommend this method to only be done by those who are experienced with their telescope and binoculars.
- Place your telescope/binoculars on a tripod and attach a shade collar onto it. It could be a piece of cardboard with a hole cut out that slots around the upper part. This will block out the sunlight so you can see the image produced. For your binoculars, you only need one side to see the Sun.
- Depending on your telescopes’ manufacturers’ guide and the type of telescope you use, you may want to reduce the amount of light let through. On the front end, you can add a circle of cardboard with a small hole cut out. It can be held in place with the dew attachment or use any suitable attachment recommended.
- Angle up to face the Sun and the light comes out on the eyepiece end to create an image on the ground. Don’t look at the Sun using the eyepiece, as the sunlight is at full strength.
- Put a sheet of paper or board underneath, ideally at an angle, to see the image of the Sun. You may see more details like sunspots in your resulting image. Keep away from the eyepiece as the light passing through will be very hot and could burn you.
A refractor telescope is ideal for this but always double check it is safe to do this with your telescope by looking at your manufacturer’s guide. Make sure there are no plastic parts to your telescope/binoculars as these could melt and damage it. Keep an eye on the temperature of your setup and allow time for cooling down during use to avoid damaging it. If you decide to use this setup, never leave it unattended and keep children well supervised!
5. Solar filters for your telescope
If you are very confident, you could use your telescopes/binoculars with a Solar filter attached to look directly at the Sun. The solar filter reduces the amount of light entering the telescope, blocking harmful UV and IR light. It lets an extremely tiny amount of visible light through, making it safe for us look through the eyepiece with our eyes.
The filter must go on the front end of the telescope for it to be effective. Always make sure that the solar filter is undamaged before using it every time.
For more advice on using your telescope as an optical projector and for using a solar filter, contact your local astronomical society and/or specialist companies selling telescopes. It is always worth seeing these in action first before attempting it yourself.
When are the next UK solar eclipses?
As you can see there are lots of ways to join in on the thrill of watching an eclipse, regardless of experience and budget. We are fortunate that between now and 2030, we have 6 partial eclipses happening in the UK for you to watch:
- 29 March 2025
- 12 August 2026
- 2 August 2027
- 26 January 2028
- 12 June 2029
- 1 June 2030
The only thing that we can’t control during an eclipse viewing is the weather in the UK…
Good luck with your eclipse viewing and enjoy, safely!
Credits:
Banner – Total Solar Eclipse 2017 – NPS/Jacob W. Frank – Public Domain
Image 1 – Time lapse of total solar eclipse 2019 – Callan Carpenter – CC BY-SA 4.0
Image 2 – Solar Eclipse Glasses – Laslovarga – CC BY-SA 4.0
Image 3 – Diagram showing how light rays travel through a pinhole – Work adapted by E. Mosley, original Bob Mellish CC BY-SA 3.0
Image 4 – Colander eclipse viewing – Joe Mabel – CC BY 4.0
Image 5 – Eclipse viewing at Grand Canyon National Park – Grand Canyon NPS – CC BY 2.0
Image 6 – A telescope with a solar filter attached – Morn (edit), original NOIRLab/NSF/AURA/J. Fenske
