The Sun is the only astronomy target you can observe at lunchtime, from a parking lot, with no light pollution worries. It changes daily: sunspot groups grow, rotate across the disk and fall apart over a week or two. It is also the only target that can permanently damage your eyes in a fraction of a second, and cook the insides of an unprotected telescope for good measure.
With a total solar eclipse crossing Iceland and Spain on August 12 and the Sun still busy after its recent maximum, this is a good moment to get solar safety right. Here is what is safe, what is not, and the specific mistakes we see at the shop. Safety rules come from NASA and the American Astronomical Society (AAS).
The Short Answer
Only look at the Sun through filters made for it: ISO 12312-2 eclipse glasses for your eyes alone, or a solar filter that covers the full front of a telescope, binoculars or camera lens. Never put eclipse glasses behind optics, and never use a screw-in eyepiece sun filter.
- Sunglasses are never safe for looking at the Sun, no matter how dark.
- Cap or remove your finderscope before pointing a telescope at the Sun.
- Inspect every filter before use and discard any that are scratched, punctured or loose.
- Totality is the only exception: during a total eclipse, filters come off only while the Sun is completely covered.
1. Safe Ways to Look at the Sun
Every safe method does one of two things: it cuts the Sun's light (including infrared and ultraviolet) by a huge factor before it reaches your eye, or it projects the image so you never look at the Sun at all. The table sums up the options.
| Method | Safe? | What you see | Notes |
|---|---|---|---|
| Eclipse glasses / handheld viewer (ISO 12312-2) | Yes, eyes only | Whole Sun, large sunspots, eclipse phases | Never behind binoculars, a telescope or a camera |
| Welding filter, shade 13 or 14 | Yes, eyes only | Green Sun | Shade 12 minimum; no auto-darkening helmets |
| Pinhole projection | Yes | Small projected image | Sun behind you; never look through the pinhole |
| Front-mounted white-light filter on a telescope | Yes | Sunspots, faculae, granulation | Must cover the full front aperture and be secured |
| Herschel wedge | Yes, refractors only | High-contrast white light | Not for reflectors or SCTs |
| Hydrogen-alpha telescope | Yes | Prominences, filaments | Dedicated, more expensive gear |
| Screw-in eyepiece "SUN" filter | No | - | Concentrated sunlight can burn through it; throw it away |
| Sunglasses, however dark | No | - | Pass far more sunlight than your eyes can tolerate |
Eclipse glasses and handheld viewers
NASA says viewers must meet the ISO 12312-2 international standard and adds that regular sunglasses, however dark, are not safe for viewing the Sun. Inspect them before each use and discard any that are torn, scratched or damaged. Supervise children. Eclipse glasses show the whole Sun, partial eclipse phases and, during active periods, the occasional sunspot group large enough to see without magnification.
Welding filters: the right shade only
The AAS says a welding filter of shade 12 or higher transmits a safely small fraction of sunlight, with shade 13 or 14 the sweet spot (shade 12 looks uncomfortably bright to most people). Welding supply stores rarely stock 13 or 14, so you may need to order one. The AAS also warns against using adjustable or auto-darkening welding helmets to view the Sun.
Pinhole projection
The cheapest safe method: poke a small hole in a card, stand with the Sun behind you and let the image fall on a second card or the ground. NASA's warning is blunt: do not look at the Sun through the pinhole. During a partial eclipse, the gaps between tree leaves project dozens of tiny crescents onto the ground.
2. Telescopes and Binoculars: Filters That Work
A telescope concentrates sunlight. That is the whole point of it at night, and the whole danger in daytime. The AAS optics guidance says solar filters must be attached securely to the front of any telescope, binoculars or camera lens, so the Sun's light and heat never enter the optics.
White-light filters: sunspots, faculae and granulation
Full-aperture filters made of glass or polymer film are the standard way to turn a regular telescope into a solar scope. Astronomy magazine notes that at 50x or more sunspots show a dark umbra and a lighter penumbra, and that bright faculae show up best near the Sun's edge. Resolving the granulation pattern takes at least a 3-inch scope, 150x and very steady air. If you make your own filter from film, use material rated for visual use, which the article specifies as ND 5.0, not the ND 3.8 grade made for photography. Check any filter by shining a phone flashlight behind it; bright spots or streaks mean it is damaged.
Herschel wedges: refractors only
A Herschel wedge replaces the star diagonal on a refractor and dumps most of the light and heat out the side. The Starfield 1.25-inch wedge is rated for refractors up to 100 mm (its 2-inch sibling to 150 mm), and the maker warns it is not for reflectors, telescopes with plastic components or certain designs with a rear lens near the focuser. Never put a filter in front of a Herschel wedge; filters go after the prism.
Hydrogen-alpha: prominences and filaments
H-alpha telescopes and filters pass only the narrow red wavelength emitted by hot hydrogen. Astronomy magazine says a bandwidth of 3 to 4 angstroms shows prominences, the flame-like arcs on the Sun's edge, while seeing filaments on the disk takes 1 angstrom or less. It is a different, more dramatic Sun than white light shows, and dedicated H-alpha scopes cost considerably more.
Ready-made solar optics
If you do not want to fit a filter to your night scope, dedicated gear removes the guesswork. Celestron's EclipSmart solar binoculars and Travel Solar Scope 50 have ISO 12312-2 filters permanently built in, so they cannot be knocked off, and the scope includes a solar finder that you aim by its shadow. For hands-free tracking, the Sky-Watcher SolarQuest mount uses GPS and a solar sensor to find and follow the Sun.
3. What Never to Do (and Eclipse Plans)
These are the mistakes that actually happen. Most involve good equipment used in the wrong order.
The never list
- Never use a screw-in eyepiece sun filter. The AAS calls the filters that thread into the eyepiece of inexpensive telescopes dangerous: concentrated sunlight can burn through them. Throw it away.
- Never look through optics while wearing eclipse glasses. NASA warns the concentrated rays will burn through the glasses' filter.
- Never forget the finderscope. The AAS says any finder must be capped, removed or filtered like the main scope. Aim with the telescope's shadow instead.
- Never leave a solar setup unattended, especially with kids around. One removed filter cap is all it takes.
- Never use a damaged filter. Scratched, punctured or loose? Discard it.
- Never point an unfiltered scope near the Sun, even for a moment while you hunt for it.
The August 12, 2026 eclipse
A total solar eclipse crosses western Iceland and northern Spain on Wednesday, August 12. NASA says the partial phase is visible from the Northeast, parts of the Mid-Atlantic and parts of the Upper Midwest in the U.S.; Georgia is outside that area. If you travel for it, the same rules apply: eclipse glasses or filtered optics for every partial phase, and filters off only during totality. NASA says to look without protection only when the Moon completely covers the Sun's bright face, and to put eyewear back on as soon as any bright sunlight reappears.
Looking ahead
The next total eclipses in the contiguous U.S. are August 23, 2044, across Montana, western North Dakota and a corner of South Dakota, and August 12, 2045, whose path runs from northern California to Florida and crosses southwest Georgia on the way. Meanwhile, the Sun is worth watching any clear day.
Why now is a good time
On October 15, 2024, NASA and NOAA announced that the Sun had reached its solar maximum period, the most active part of its roughly 11-year cycle. Activity winds down over the years after maximum, but sunspot groups are still common, so a white-light filter shows something new most weeks.
Conclusion
Solar observing is safe when the filter is the right kind, in the right place, and in good condition: ISO 12312-2 viewers for your eyes, full-aperture front filters for optics, Herschel wedges only on refractors, and nothing at the eyepiece end. Cap the finder, inspect every filter, and stay with the scope. Do that and you get a star you can watch change from day to day.
Not sure if your filter fits your telescope or is still safe? Bring it by our Cumming showroom and we will check it. Browse our solar viewing gear or contact the shop.
Gear Mentioned in This Guide
Celestron EclipSmart Travel Solar Scope 50
Dedicated white-light solar scope with a permanently attached ISO-compliant filter and a solar finder.
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Celestron EclipSmart 10x42 Solar Binoculars
Built-in ISO 12312-2 filters that cannot be knocked off; whole solar disk in view.
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Celestron EclipSmart Eclipse Glasses Observing Kit
Four ISO-certified eclipse glasses for naked-eye viewing of sunspots and eclipses.
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EclipSmart 8-Piece Observing & Imaging Kit
Eclipse glasses plus a solar-safe photo filter for phones and cameras.
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Starfield 1.25" Herschel Solar Wedge
High-contrast white-light views for refractors up to about 100 mm, never reflectors.
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Sky-Watcher SolarQuest Mount
GPS and a solar sensor find and track the Sun automatically for a solar telescope.
Shop nowFrequently Asked Questions
Can I use eclipse glasses with my telescope or binoculars?
No. Eclipse glasses are for your eyes only. Optics concentrate sunlight that can burn through the glasses' filter. Telescopes and binoculars need their own solar filter mounted on the front.
Is the sun filter that came with my old telescope safe?
If it screws into the eyepiece, no. These eyepiece filters sit where sunlight is concentrated, and the AAS warns it can burn through them. Discard it and use a full-aperture front filter instead.
Are sunglasses safe for looking at the Sun?
No. NASA states that regular sunglasses, no matter how dark, are not safe for viewing the Sun. Use ISO 12312-2 eclipse glasses or a handheld solar viewer.
How do I know if my eclipse glasses are safe?
They should meet the ISO 12312-2 standard and come from a reputable supplier. Before each use, check for scratches, holes or a loose filter; discard any damaged pair.
Can I use a Herschel wedge on my Dobsonian?
No. Herschel wedges are for refractors only. Reflectors, Schmidt-Cassegrains and telescopes with plastic parts should use a full-aperture front filter.
Can I see the August 12, 2026 solar eclipse from Georgia?
No. NASA shows the partial phase reaching only the U.S. Northeast, parts of the Mid-Atlantic and the Upper Midwest. Totality crosses Iceland and Spain.
