How to observe an eclipse safely
What are the best and safest ways to view an eclipse?
A solar eclipse is a wonderful thing. Those of us who have been lucky enough to witness totality are well aware of the ethereal, life-changing moment that occurs when darkness descends and the the Moon blocks out the light from our host star the Sun.
Of course, not all solar eclipses are total solar eclipses. Depending on where you view the eclipse, you many only see a partial solar eclipse.
- Find out when the next eclipse is taking place
When observing the Sun, safety is key. You should never observe the Sun with the naked eye or with homemade equipment.
Only ever use certified solar filters, solar telescopes or eclipse glasses to observe the Sun or a solar eclipse.
Here are some ways you can safely observe a solar eclipse.
Projection through a colander
Simply hold up a kitchen colander during an eclipse and you will see that myriad small crescents – corresponding to the eclipsed phase of the Sun – are cast in the shadow.
Casting the image onto a white piece of card held about 50cm away will increase the contrast.
The only downside is the size of the crescents are quite small, so no details such as sunspots can be seen.
- Cheap and easy
- Great for large groups of people
- Views are quite small
- No detail can be seen apart from the crescents
- Piece of white card
Simply put on your certified solar eclipse glasses and look up!
The glasses allow you to see the detail of the Sun with your own eyes, but unfortunately don't allow you to take any photos.
Be sure to check the lenses for scratches and tears first.
- Can see some of the Sun's detail
- Cannot take images
- Cannot see as much detail as with a solar telescope
- Get a pair of solar eclipse glasses from a certified retailer. Accept no substitutes!
View through a white light filter
One of the safest ways to view an eclipse is to fit a white light filter over the front of your telescope.
Filters are relatively simple to make using sheets of certified solar film cut to size.
Once you’ve made your filter, you must check it for pinprick holes and tears each time you’re about to fit it. If you find any, discard the filter and make a new one.
Make sure that the mask fits over the entire aperture and that no light can leak around its edges
When you use the filter, it’s important to also remove or cap your telescope’s finder.
Always make sure the telescope is pointing away from the Sun before fitting the filter.
When you’re done observing, do the same – aim the telescope away from the Sun before removing it.
- Can be adapted to fit any telescope
- Quick and portable option
- Can see good detail on the Sun
- Requires careful construction (if in doubt, don't attempt!)
- Materials used are perishable and must be checked for defects
- Solar safety film
- Sticky tape
View in Hydrogen Alpha
A variety of manufacturers offering dedicated hydrogen-alpha telescopes or filter sets that fit onto regular telescopes.
A dedicated hydrogen-alpha refractor offers the easiest and most affordable way to see our star in this way.
All you need is a suitable mount and eyepiece to get observing.
If you already own a good refractor or Schmidt-Cassegrain telescope, it is possible to buy an etalon filter system to go on the objective lens, and used with a blocking filter on the rear of the scope it offers excellent views.
Whichever method you choose hydrogen-alpha views are simply stunning, with a wealth of features on show.
- Great levels of detail
- Options available for using regular scopes
- More expensive than other methods
- A hydrogen alpha refractor
- Or an etalon filter system
Use a solar projection screen
It is possible to project a view of the Sun or a solar eclipse onto a screen, allowing for safe observation of our host star.
For more info, find out how to make a solar projection screen.
- Incredibly safe, as you are observing the Sun indirectly
- Good for observing in groups
- Easy and safe for children to see
- Requires a bit of preparation
- Lack of detail on solar surface