Is a white light solar filter safe to use?

One thing I have to mention, and I will mention every single time I talk about looking at the Sun: don't, not without specialised equipment such as a solar filter, but even then take extreme precaution. Your eyes are delicate, they are precious.

How does it fit on a telescope?

It sits in the small opening in the front lens cap, where the cap's little plug comes out, so the rest of the cap keeps covering the lens. Mine fitted the cap of my 5.5 inch telescope.

What will I see through it?

Sunspots on the Sun's surface in white light, which change from day to day as they cross the disc, grow and fade. Prominences need a hydrogen-alpha telescope.

Can I use it with just my phone?

I held it in front of a Samsung S20 Ultra at up to 100x zoom in my solar comparison: the faintest sunspots showed, and I rated that setup 2 out of 10, not much better than the naked eye.

What have I not tested on the white light solar filter?

I have not measured the filter's optical density or had it tested; the density and the test standard of the film I link are the maker's.

White light solar filter review: sunspots through a lens cap

Where does it rank on our leaderboard

Nine of the 46 accessories on my board, against price
Rank	Accessory	Stars for Your Buck	Recorded UK price
1	GEMINI EAF	100 out of 100	£42
2	Generic Dew Heater	93 out of 100	£9
8	Generic Guide Scope 60mm	85 out of 100	£109
16	White light solar filter	78 out of 100	£17
17	Red light headlamp	77 out of 100	£6
25	ZWO 7x2″ Filter Wheel	71 out of 100	£398
42	Celestron Binoviewers	40 out of 100	£242
45	SKY ROVER 2x54 Binoculars	28 out of 100	£139
46	365 Solar Telescope Cover	5 out of 100	£73

Contents

01 Where does it rank on our leaderboard
02 Specifications and features
03 In use
04 Watch it in my videos
05 Should you buy it?
06 Questions and more about this review

In 30 seconds

Stars for Your Buck 78/100

Reviewed 13 Dec 2023 Updated 26 Sep 2026

Rank: #16 of 46 accessories
Verdict: Damon recommends

Written by Damon Scotting 2 min read

Buy it if

You want your first look at sunspots for very little money.
Your telescope's lens cap has a small opening the filter can sit in, or you are happy to cut solar film to cover the front of your telescope.

Skip it if

You want prominences and the chromosphere: that needs a hydrogen-alpha telescope such as the Coronado PST.
You plan to hold it in front of a phone with no telescope behind it: that view is barely better than the naked eye.

It lets you observe our nearest star in white light and get a proper look at the sunspots.

Amazon £17 Ad

Specifications and features

White light solar filter reviewed #16 of 46
Recorded UK price	£17
Type	White-light solar filter
The filter in my videos	A small round filter, about 40 mm, that sits in the opening of a telescope lens cap
What it shows	Sunspots on the Sun's surface
The film I link	Absolute Eclipse solar filter sheet, 150 x 150 mm; also sold in 100 and 210 mm
Optical density of that film	OD 5.6 or higher
Test standard of that film	EN ISO 12312-2:2015, tested by ICS Laboratories
Fitting	Silver side to the Sun, trimmed with at least 10 mm of overlap, in front of the objective, never behind the eyepiece

In use

The filter in its case

A lens cap with its small plug out

The filter over the opening

The filter fitted in the cap

The filter's case

Watch it in my videos

The 9 COOLEST Accessories for ASTRONOMY! · published 13 December 2023 · 17:00 · Watch on YouTube · 19,597 views, 974 likes on 2 Oct 2026

Jump to

12:41 Accessory number 8: the solar filter
12:48 Fitting it in a lens cap
13:10 Why the Sun needs filtering
13:17 Sunspots in white light
13:24 Watching sunspots change day to day
13:36 Solar safety

Transcript of the video 286 words · 6 chapters · searchable

Press a time stamp to play from there.

12:39 The opening

12:40 is very toasty right now so I'm going to pop that back inside there accessory number eight this costs just under $10 it is a solar filter now what you can do

12:48 Fitting it in a lens cap

12:49 with this is on most telescope covers the lens cap at the very top they have smaller holes in which you can mount something like this solar filter onto it 12:58 I actually have a 5 and half half in telescope that's only a few feet away from me but I mounted this onto it earlier and it fit perfectly you are 13:05 technically still stargazing when you're using one of these but you're focusing on one very specific star and that is our sun the light coming from it is so

13:10 Why the Sun needs filtering

13:13 overwhelming that we have to heavily restrict the amount we are receiving from it which is where this comes in handy now it allows us to observe the

13:17 Sunspots in white light

13:19 sun in White Light which means we can make out the sun spots on the surface of it which is very cool you can watch them

13:24 Watching sunspots change day to day

13:26 dayto day and see how they change and move across surface of the sun it's really exciting to watch them develop and eventually dissipate and the fact 13:33 that you can get something like this for only $10 is really cool which is why I think it deserves a place on this list

13:36 Solar safety

13:39 but one thing I have to mention and I will mention every single time I talk about looking at the sun don't not without specialized equipment such as a 13:47 solar filter but even then take extreme precaution your eyes are delicate they are precious don't destroy them by being a dum dum okay which brings us to the

Check out more videos on the White light solar filter

What YOU can SEE through a $10, $500 and a $1,000 SOLAR Telescope!

29 Dec 2023

Should you buy it?

78/100 Stars for Your Buck

Pros

Very affordable if you buy the film and make your own DIY filter.
White light gives a completely different perspective on stargazing: a really cool and underrated aspect of astrophotography.
“On most telescope covers, the lens cap at the very top, they have smaller holes in which you can mount something like this solar filter onto it.”
It fitted the small opening in the lens cap of my 5.5 inch telescope perfectly.
Sunspots in white light, which you can follow from day to day as they change, cross the Sun's disc and fade.

Cons

With only a phone behind it, the view rated 2 out of 10 in my solar comparison: the faintest sunspots, not much better than the naked eye.
White light only: it shows sunspots on the surface, never the prominences a hydrogen-alpha telescope shows.
It must be the first thing the sunlight meets, in front of the lens, and never behind the eyepiece.

The fact that you can get something like this for only $10 is really cool.

Three alternatives I have reviewed

Questions and more about this review

Reviewed by

Damon Scotting

The Telescope Man Verified

BSc (Hons) Physics with Astrophysics and Cosmology, Loughborough University PGCE / QTS, University of Nottingham

About Damon About Damon Damon Scotting is The Telescope Man. He holds a BSc (Hons) in Physics with Astrophysics and Cosmology from Loughborough University and a PGCE with QTS from the University of Nottingham, and taught physics in secondary schools before becoming an astronomy creator. He is a contributing writer for BBC Sky at Night Magazine and the author of 42 Wonders of Our Night Sky, and his photograph of the galaxy M100 with the dwarf planet Ceres was Highly Commended in the Astronomy Photographer of the Year 2024 competition run by Royal Observatory Greenwich. He has appeared on the BBC's Blue Peter. More than 750,000 people follow his astronomy channels on YouTube, Instagram and TikTok, and he has reviewed more than 140 telescopes, mounts, cameras, filters and accessories hands-on for this site. More about Damon · How I test · Damon's book

I review all kinds of gear: most of it I buy, some is gifted and some is loaned, and all of it is reviewed the same way. How this site is funded

Five questions, answered

Questions about the White light solar filter

Reviewed 13 December 2023 ·Updated 26 September 2026

I review all kinds of gear. Most of it I buy, some is gifted and some is loaned, and all of it is reviewed the same way: no company sees or approves a review before it is published. Shop links marked Ad are affiliate links: I earn a commission when you buy through them, at no extra cost to you. How this site is funded

Is a white light solar filter safe to use? One thing I have to mention, and I will mention every single time I talk about looking at the Sun: don't, not without specialised equipment such as a solar filter, but even then take extreme precaution. Your eyes are delicate, they are precious. From my video review Watch it in my videos ↓
How does it fit on a telescope? It sits in the small opening in the front lens cap, where the cap's little plug comes out, so the rest of the cap keeps covering the lens. Mine fitted the cap of my 5.5 inch telescope. In use ↓
What will I see through it? Sunspots on the Sun's surface in white light, which change from day to day as they cross the disc, grow and fade. Prominences need a hydrogen-alpha telescope. Watch it in my videos ↓
Can I use it with just my phone? I held it in front of a Samsung S20 Ultra at up to 100x zoom in my solar comparison: the faintest sunspots showed, and I rated that setup 2 out of 10, not much better than the naked eye. Watch it in my videos ↓
What have I not tested on the white light solar filter? I have not measured the filter's optical density or had it tested; the density and the test standard of the film I link are the maker's.