Solar observing and imaging
The one object that's up while you are
The Sun needs no dark sky, no late night and no drive out of town. It also changes every day, and in hydrogen-alpha it changes while you watch. This page covers the safe ways to look at it, from a $66 pair of solar binoculars to a dedicated 100 mm hydrogen-alpha telescope.
Read this part first
The rules here are short, and none of them are negotiable
Never point anything at the Sun without a filter made for it
Unfiltered sunlight through even a small telescope causes immediate, painless and permanent damage. There is no such thing as a quick look. This is the one corner of astronomy where being casual has consequences you cannot undo, and it is why we would far rather you asked us a question you think is obvious than guessed at it.
- A white-light filter goes on the front, covering the full aperture. Screw-in "sun filters" that shipped with older beginner scopes thread in at the eyepiece, where every bit of collected heat is concentrated on a small piece of glass. They can crack in use. Throw them away.
- Cover or remove the finder scope too. It is the step people forget, and it will burn whatever is behind it.
- Inspect film and filters against a bright lamp before every session. Pinholes, scratches or a tear mean it is finished. Solar film is a consumable, not a fitting.
- A Herschel wedge is for refractors only. It works by throwing almost all of the Sun's energy out of the back of the prism, which a catadioptric or a reflector cannot do safely. Never fit a filter in front of a wedge either - anything ahead of the prism sits in the full heat load and can fail. Filters go after the prism, never before it.
- A dedicated hydrogen-alpha telescope is a safe complete system. A Quark is not a telescope. It is a filter that goes into a refractor you supply, and that refractor needs heat management sized to its aperture: a full-aperture energy rejection filter at the front for 120 mm and above, or a 1.25 inch UV/IR filter ahead of the Quark at 102 mm and below. Tell us which scope you plan to use and we will tell you which one it takes.
If you are not certain whether something you already own is safe to use on the Sun, send us a photograph of it rather than guessing. We would far rather be asked that question than not be asked it.
Two different Suns
White light and hydrogen-alpha are not the same hobby
They show different layers of the Sun, cost an order of magnitude apart, and answer different questions. Worth understanding before you spend anything.
White light shows you the surface
A front filter throws away almost all of the incoming light and leaves you looking at the photosphere: sunspots, the granulation around them, and bright faculae near the limb. There are three ways to get there: solar binoculars with the filtering built in, a sheet of certified film you cut to fit a telescope you already own, or - on a refractor - a Herschel wedge, which gives noticeably more contrast than film. Celestron also make filters cut for specific models of their own telescopes; those are offered on each of those telescopes' own pages.
Hydrogen-alpha shows you the atmosphere
An H-alpha filter passes a slice of the spectrum under a nanometre wide, and the layer above the surface appears: prominences arcing off the limb, dark filaments snaking across the disc, flares that visibly change while you watch. This is the view people take up solar for, and there is no cheap route to it.
A Quark converts a refractor you own
The Quark is a heated H-alpha filter with its own telecentric barlow that drops into a refractor's focuser. It wants power, about ten minutes to reach temperature, a host scope in the right focal-ratio range, and heat management matched to that scope's aperture - a full-aperture front filter at 120 mm and above, a 1.25 inch UV/IR filter at 102 mm and below. Which is precisely why this is a conversation to have before you order rather than after.
| White light | Hydrogen-alpha | Calcium K | |
|---|---|---|---|
| What you see | Sunspots, granulation, faculae near the limb | Prominences, filaments, flares and surface texture | Bright plage and the chromospheric network |
| Cheapest way in | Solar binoculars at $66, or a sheet of film you cut yourself | A Quark on a refractor you already own | A Calcium Quark, same idea |
| Works with | Any telescope, binocular or lens filtered at the front - or a Herschel wedge in a refractor | Refractors inside the right focal-ratio and aperture range | Refractors, and realistically a camera rather than an eye |
| Changes over | Days - a spot group takes about two weeks to cross | Minutes to hours - you can watch a prominence move | Days |
| Best for | A first look, transits, and eclipse day | The reason people keep coming back to solar | Imaging, as a second channel alongside H-alpha |
Two honest notes. Calcium K sits at the very edge of human colour vision - most people see almost nothing through it visually, so treat it as an imaging line rather than an observing one. And white light and hydrogen-alpha are not the same hobby at different budgets: they show different layers of a different Sun. Very few people who have looked through H-alpha find that white light scratches the itch afterwards, which is worth knowing before you spend the sixty dollars expecting it to.
The ladder
Seven ways to look at the Sun, cheapest first
The first needs no telescope at all. The next three use one you already own. The last three are dedicated solar instruments. The jump from white light to hydrogen-alpha in the middle is a real one, and we would rather you made it deliberately than by accident.
Celestron EclipSmart solar binoculars
Binoculars with the solar filters built permanently into the optics, so there is nothing to attach, nothing to make and nothing that can be left off by mistake. Point them at the Sun and you see sunspots. That is the whole procedure.
Safe by design - the filtering is inside the instrument, not something you fit to the front. Ideal for eclipse day, for a family, and for anyone who does not own a telescope.
They only do one thing. The Sun is the only object you can ever point them at, and the view is a modest one next to a filtered telescope.
There is also a 10x25 at $66 if you want something pocketable to hand round on eclipse day.
DayStar SafeSight SolarLite film
A sheet of certified solar film that you cut and mount over the front of a telescope, binocular or camera lens you already own. Built into a properly fitted cell it gives you a full-aperture white-light filter showing sunspots and granulation.
The only way to put a white-light filter on most telescopes. One sheet covers a scope, a finder and a camera lens.
You are making the filter, so making it properly is on you. It has to cover the full aperture, fit so it cannot be blown or knocked off, and be checked for pinholes before every single use.
A 12 x 12 sheet is 305 mm across, and you need real margin beyond the outside diameter of the tube to build a cell that stays put - so it suits apertures up to about 150 mm. The 12 x 20 is not wider, only longer: it makes several filters for smaller apertures out of one purchase. If you need to cover something bigger than the sheet, ask us.
Starfield Herschel solar wedge
A Herschel wedge replaces the diagonal in a refractor and throws almost all of the Sun's energy out of the back of the prism, passing a small safe fraction to the eyepiece. With nothing sitting in front of the objective there are no reflections between filter and lens, and the contrast on granulation and sunspot detail beats film comfortably.
The sharpest, highest-contrast white-light view available, with brightness adjustable while you observe by rotating the built-in polarising filter. Imaging-ready without taking the camera off.
Refractors only - the heat has to go somewhere, and a catadioptric or a reflector will trap it. Not suitable for Petzval designs with a rear lens close to the focuser, or for tubes with plastic in the light path.
Never fit a filter in front of a wedge: anything ahead of the prism sits in the full heat load and can fail. Filters go after the prism only. The 1.25 inch suits refractors to about 100 mm, the 2 inch to about 150 mm.
DayStar Quark H-alpha
A heated hydrogen-alpha filter with its own telecentric barlow that drops straight into the focuser of a refractor. Give it power and about ten minutes to reach temperature and you are looking at the chromosphere through glass you already own.
By a wide margin the cheapest route to a real H-alpha view, and it travels in a coat pocket.
It needs a refractor in a suitable focal-ratio range, plus heat management sized to that refractor: a 1.25 inch UV/IR filter at 102 mm and below, or a machined-to-order full-aperture energy rejection filter from around $781 at 120 mm and above. This is the one product on the page you should not order without telling us what it is going on.
Chromosphere is tuned for detail across the disc; Prominence is tuned wider for the limb. Most people who own one own the Chromosphere. Same price either way.
DayStar Solar Scout 60 DS bundle
A purpose-built hydrogen-alpha telescope with the filter already inside and matched to the optics, double-stacked for higher contrast. There is no compatibility question to answer and no host scope to buy - it is a solar telescope, and that is all it does.
Contrast. Double stacking narrows the passband, and filaments on the disc stand out in a way a single stack cannot match.
Sixty millimetres is a modest aperture, so fine detail is limited by the optics rather than the filter. It still needs a mount and tripod, which are not in the box.
It sits happily on a sturdy photo tripod for casual viewing, or on the SolarQuest below if you would rather it found and tracked the Sun by itself.
Sky-Watcher Heliostar 76
Seventy-six millimetres of dedicated hydrogen-alpha with a tunable etalon, so you can shift the passband on and off the line to favour surface detail or prominences while you are at the eyepiece. A real step up in both aperture and adjustability from a 60 mm.
Detail, and the tuning. Being able to adjust while you observe is the difference between seeing a filament and watching it change.
This is where solar gets expensive, and the aperture is large enough that unsteady air starts to limit you on poor days.
The SolarQuest version adds a mount that finds and tracks the Sun on its own - no alignment and no star to align on, just switch it on and it locks. If you picture yourself observing on weekday lunch breaks, that is the version to have.
Sky-Watcher Heliostar 100
A hundred millimetres of hydrogen-alpha. At this aperture the atmosphere is the limit rather than the telescope, and surface texture holds together under real magnification - which is why this is the one people image with.
Resolution. Fine structure in filaments and prominences that smaller H-alpha scopes only hint at.
The price, the weight, and a mount requirement to match. Nothing about this one is a casual purchase.
The kit version pairs it with a Wave 100i strain-wave mount, which will carry the telescope and a camera without complaint.
Or ask first
Tell us what you already own
Most solar questions we get are some version of 'will this work with that', and they are much cheaper to answer before money changes hands. Send us a photograph of your telescope and we will tell you what is safe, what fits, and what you would need to add. Everything ships factory-sealed.
- Which of the telescopes you own is safe on the Sun, and how to filter it
- Whether a Quark will work on your refractor, and which heat-management filter its aperture calls for
- White light first, or straight to hydrogen-alpha
- What mount will carry it, and whether solar tracking is worth it for how you observe
Worth adding
The parts that come up second
Mostly Quark accessories, because that is where the questions land. Which of the two energy filters you need depends on your refractor's aperture, and the full-aperture one is machined to fit one specific tube - so settle that with us rather than picking a size off this strip.
For a Quark on a refractor of 120 mm or more: a full-aperture filter that fits over the front of the telescope. Each one is machined to order, so measure the outside diameter of your dew shield at the very front and give us that figure with the order.
From $781Choose a version
For a Quark on a refractor of 102 mm or less: a 1.25 inch UV/IR filter that threads on ahead of the Quark and sheds the heat load that way. Far cheaper than a front filter, and the right answer at these apertures.
$68.60
A Quark is heated, so it draws power for as long as you observe. This runs one all day well away from a socket.
$139.99
Lets the Quark take 2-inch eyepieces, which is how you get the widest full-disc view it is capable of.
$94.99
Puts a camera on the back of the Quark instead of an eyepiece. Usually the first thing people want once they have actually looked.
$89.99
The Quark's built-in 4.2x telecentric multiplies your focal length, so on a longer scope the whole solar disc will not fit in the field. This pulls the image scale back so it does.
$284.99
A mount that finds and tracks the Sun by itself - no polar alignment and no star to align on. Switch it on at lunchtime and it locks.
$810
Calcium K, a second wavelength alongside hydrogen-alpha. It sits at the edge of human colour vision, so treat it as an imaging filter rather than a visual one.
$1,844.99Dobsonians, a grab-and-go refractor and binoculars. The night-time half of looking through an eyepiece.
Photographs Imaging the sky at nightSolar imaging uses the same cameras and much of the same software as planetary work. That page starts from scratch.
Learn it Lunar & Solar System imaging workshopCapture, stacking and wavelets, live on Zoom and recorded. The processing side is most of the result.
Free tool Astronomy weather forecastSolar wants steady air far more than it wants a clear night. Check the seeing before you set up.
Ask us before you order, not after it arrives
Solar is the corner of this hobby where the compatibility question genuinely matters, and we would far rather answer it first. Everything ships factory-sealed. If something needs service later, our repair bench is here in Canada.