<p>The device you saw was probably a &quot;solar projection eyepiece&quot;. You can use any eyepiece for this, in theory, though eyepieces with cemented lenses can heat up in the sun and the glass can crack.<br />
Personally I wouldn't feel comfortable using one of those with my telescope.</p>
<p>Instead:</p>
<p>You can use solar film specially designed for looking at the sun, such as Baader's <a href="https://www.baader-planetarium.com/en/astrosolar-safety-film-od-5.0-(20x29-100x50-117x117-cm).html" rel="noreferrer">&quot;AstroSolar Safety Film&quot;</a> which comes in a variety of sizes.</p>
<p>The link above is for just the film, but if you want to use it with a telescope then they also sell the film <a href="https://www.baader-planetarium.com/en/solar/whitelight/astf-astrosolar-telescope-filter-od-5.0-(80mm---280mm).html" rel="noreferrer">mounted in a frame</a> which clips onto the front of your telescope.</p>
<p>Further down the line, if you get more into solar observation, then you may want to look into buying a <a href="https://en.wikipedia.org/wiki/Herschel_wedge" rel="noreferrer">Herschel Wedge</a> which filters the light after it's passed through the telescope, so shows more detail.</p>

CC BY-SA 4.0
2023-09-08T13:27:39.443Z
2023-09-08T13:27:39.443Z
Aaron F
<p>In 2016 I got to see the transit of Mercury thanks to a group of volunteer astronomers. The astronomer had a device attached to the telescope eyepiece that allowed the light to project onto frosted glass.</p>
<p>I’d like to get such a device for my own telescope for viewing the next two solar eclipses, but I don’t know what this device is called. I’ve Googled various things, but I’ve had no luck.</p>

CC BY-SA 4.0
2023-09-08T15:42:21.280Z
I used a sun funnel for the partial solar eclipse in 2017. It worked far better than I expected, even with my awful cheap old telescope. See here for a link: https://eclipse2017.nasa.gov/make-sun-funnel.
Ed V
<telescope><solar-eclipse>
Attachment for viewing the sun with a telescope
sv_lane
# Attachment for viewing the sun with a telescope

(Asked by: username_0 on 2023-09-08)

In 2016 I got to see the transit of Mercury thanks to a group of volunteer astronomers. The astronomer had a device attached to the telescope eyepiece that allowed the light to project onto frosted glass.

I’d like to get such a device for my own telescope for viewing the next two solar eclipses, but I don’t know what this device is called. I’ve Googled various things, but I’ve had no luck.

**Tags:** telescope, solar-eclipse
> **Comments:**
> **username_1**: I used a sun funnel for the partial solar eclipse in 2017. It worked far better than I expected, even with my awful cheap old telescope. See here for a link: https://eclipse2017.nasa.gov/make-sun-funnel.  

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## 1 answers

### Answer by username_2 on 2023-09-08. Score: 6 | Accepted answer

The device you saw was probably a "solar projection eyepiece". You can use any eyepiece for this, in theory, though eyepieces with cemented lenses can heat up in the sun and the glass can crack.  
Personally I wouldn't feel comfortable using one of those with my telescope.

Instead:

You can use solar film specially designed for looking at the sun, such as Baader's ["AstroSolar Safety Film"](https://www.baader-planetarium.com/en/astrosolar-safety-film-od-5.0-(20x29-100x50-117x117-cm).html) which comes in a variety of sizes.

The link above is for just the film, but if you want to use it with a telescope then they also sell the film [mounted in a frame](https://www.baader-planetarium.com/en/solar/whitelight/astf-astrosolar-telescope-filter-od-5.0-(80mm---280mm).html) which clips onto the front of your telescope.

Further down the line, if you get more into solar observation, then you may want to look into buying a [Herschel Wedge](https://en.wikipedia.org/wiki/Herschel_wedge) which filters the light after it's passed through the telescope, so shows more detail.


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