The best filter for viewing the Moon with a telescope is a neutral density filter that passes roughly half the light, screwed onto the front of a 1.25 inch eyepiece. It trims the glare, keeps the Moon its natural grey and brings back crater rims you could not see unfiltered. If your scope is 8 inches or larger, drop to about 13 percent transmission instead.
That is the short answer. The long answer is that this roundup of the best telescope filters for Moon viewing covers ten options, from a single threaded glass disc to a seven-piece colour kit, and the right one depends mostly on your aperture and how bright the Moon is that night.
I have spent a lot of evenings with these things screwed into the same 6 inch refractor and an 8 inch dobsonian, and the pattern that repeats is simple: filters that dim light work, filters that add colour mostly add a cast. That is worth understanding before you spend anything, so I will start with what a Moon filter actually does.
If you are still choosing glassware rather than filters, our binoculars for viewing the Moon guide covers the wider aperture question, and our telescope picks for deep space covers the scopes that pair best with a filter once you move off the Moon.
Updated for October 2026. Every rating and review count below is copied from the product listing as it stood when we compiled this roundup.
Table of Contents
Top 3 Telescope Moon Filters in 2026
Three filters earn a place on the short list before we get into the details. The first is the default choice for almost anyone, the second is the one to reach for when the aperture is large, and the third is the highest rated of the ten.
Celestron Moon Filter 1.25 inch
- Cuts lunar glare and boosts contrast
- Threads onto most 1.25 inch eyepieces
- Also useful on bright planets
- Model 94119-A
Celestron Neutral Density 13 percent
- 13 percent light transmission
- True colour view with no tint
- Scratch resistant coating
- Fits 1.25 inch eyepieces
SVBONY Variable Polarizing Filter
- Transmission adjustable 1 to 80 percent
- Neutral glass keeps natural Moon colour
- Standard 1.25 inch threads
- Anti reflective coating
Two honest notes before we go further. None of these filters add resolution, and none of them improve atmospheric seeing. What they do is make an already-bright image comfortable enough that you can keep looking at it, which is where the detail was hiding all along.
Best Telescope Filters for Moon Viewing at a Glance
If you want the whole list in one place, this is the comparison table. Ten filters, ordered as they appear in the detailed reviews below.
| Product | Specifications | Action |
|---|---|---|
| Celestron Moon Filter for Telescopes – Fits Most 1.25 inch Eyepieces |
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 Neewer 1.25 inch Telescope Moon Filter and 5 Colour Filter Set |
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| Celestron Neutral Density 1.25 inch Telescope Eyepiece Filter |
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 SVBONY Telescope Filters 1.25 inch Moon, CPL and Five Colour Filter Kit |
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| SVBONY 1.25 inch Variable Polarizing Moon Filter |
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 SVBONY 2 inch Moon Filter for Telescope |
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 Celestron Lunar and Planetary Filter Set for 1.25 inch Eyepieces |
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 Astromania Telescope Filter Moon Filter 1.25 inch ND96-0.9 |
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 starboosa 1.25 Inch Telescope Moon Filter for Eyepieces |
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 Astromania 2 Inch Moon and Skyglow Lunar Filter |
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What a Moon Filter Actually Does, and What It Cannot Do
A telescope Moon filter is a small threaded glass disc that screws onto the front of a 1.25 inch or 2 inch eyepiece, diagonal or adapter. It absorbs a fixed proportion of the light coming through, and that proportion is stated as visible light transmission, or VLT.
Without a filter, the full Moon is so bright that your retina saturates. Everything flattens into a featureless white disc, you squint, and after twenty minutes your eye is tired. Dimming the disc brings back crater rims, ray systems, the boundaries of the maria and the shadowed relief along the terminator, which is the line where day meets night on the lunar surface.
It is worth defining VLT precisely, because the numbers confuse people. A filter marked 50 percent passes half the incoming light. A filter marked 13 percent passes roughly one eighth. Higher transmission means a brighter view, so counterintuitively the gentler filters carry the bigger number.
What a Moon filter cannot do
These four claims come up constantly in forum threads, and none of them are true. First, filters add no resolution. The detail limit is set by your aperture and the atmosphere, and glass in the eyepiece barrel does not change it.
Second, filters do not improve seeing. A night of unsteady air will look unsteady with or without a filter. Third, a Moon filter does not cut light pollution in any meaningful way, so do not buy one for a city backyard expecting nebulae to appear.
Fourth, a Moon filter is not a solar filter and cannot be used to look at the Sun. Solar viewing requires an ISO 12312-2 certified filter fitted over the entire aperture of the instrument, never an eyepiece filter, and never a combination of the two.
Neutral Density vs Colour Filters for the Moon
This is the single most confused comparison in the whole category, so here is the short version. Neutral density filters absorb a fixed fraction of every wavelength equally, so the Moon stays grey. Colour filters pass some wavelengths and block others, trading brightness for contrast on specific features.
For the Moon specifically, neutral density is the safer default. It does the one job you need done, it does not shift the colour of a naturally grey object, and it works at every phase without rethinking. That is why our number one pick is a neutral density filter and not an orange one.
That is not the whole story, though. Experienced observers have long defended a Wratten 21 orange as the best contrast filter for lunar work, and the argument is legitimate: blocking the green and blue ends of the spectrum slightly darkens the low-albedo maria relative to the bright highlands, so the boundary between them reads more sharply. You pay for that in a warm cast and a dimmer view.
The classic advice that yellow improves the Moon is weaker than it sounds. The Moon reflects nearly neutral sunlight, so a yellow disc mostly gives you a yellow Moon. On some scopes and some phases it does lift surface contrast, and plenty of owners report being pleased by it, but the effect is far smaller than the internet suggests.
Decoding the Wratten numbers is worth learning, because it is the standard naming system every filter label uses. These are the numbers you will meet most often in this category.
Wratten 12 is a deep yellow that cuts brightness gently and warms the view. Wratten 21 is orange, a step darker, and the colour most often recommended for lunar contrast. Wratten 23A is light red, used more for Mars than for the Moon. Wratten 56 is bright green, historically promoted for fine lunar detail. Wratten 82A is light blue at roughly 73 percent transmission, which makes it a gentle dimmer as well as a planetary colour filter. Wratten 80A is a deeper blue that passes much less light.
Alongside those sits the neutral density family. ND96-0.3 passes about 50 percent and is the gentle option. ND96-0.9 passes about 13 percent and is the strong option for big apertures. The 0.3 and 0.9 numbers describe optical density rather than transmission, and that is why they feel backwards when you first meet them.
1. Celestron Moon Filter for Telescopes – the Best Moon Filter for Most Beginners
Celestron Moon Filter for Telescopes – Fits Most 1.25″ Eyepieces
Threads onto most 1.25 inch eyepieces
Cuts lunar glare and boosts contrast
Also useful on bright planets
Model 94119-A
Pros
- Noticeably reduces lunar glare and reveals craters and shadows
- Threads on in seconds and fits both Celestron and Plossl 1.25 inch eyepieces
- Works across refractor and Newtonian setups
- Good first filter for beginners and kids
Cons
- Not dark enough to fully tame a full Moon
- Arrives in a plain cardboard box with no case
- Slight green tint in astrophotography
This is the filter I keep coming back to, and it has earned that by being unremarkable in the best possible way. It is a plain neutral density disc on a standard 1.25 inch thread, and on a 6 inch refractor at first quarter it turns a flat white plate into a Moon with visible crater relief.
The installation takes seconds. It threads onto the front barrel of a 1.25 inch eyepiece or onto the face of a star diagonal, and because it is such a common thread it fits almost anything in that format, including Plossls that did not come from the same brand.
What I notice most is that the filter does not tint the view. The Moon through it still looks like the Moon, which is exactly what you want if you are learning to judge terminator shadows and mare edges. The manufacturer also notes it works on very bright planets and on bright terrestrial targets such as sand or snow.
Owners consistently report the same two things in reviews: it makes the Moon comfortable for long sessions, and it is the cheapest thing that makes a real difference. With 2471 reviews and a 4.5 average, that is about as safe a recommendation as this category offers.
Who this filter suits
It suits anyone with a telescope up to about 6 inches in aperture who views the Moon at anything brighter than first quarter. It is the right default because 50 percent transmission is gentle enough that you will never point it at the Moon and see nothing.
It also suits people who are not sure filters are for them. Because the effect is immediate and the price is small, this is the least risky way to find out whether dimming your Moon changes your observing life.
Where it falls short
The honest limitation is brightness, not quality. At full Moon on a large scope, half the light is still too much, and reviewers note that some eye strain remains on the brightest nights. If you own an 8 inch or larger instrument, look at the 13 percent option further down instead.
For anyone photographing the Moon through a phone or camera adapter, reviewers mention a slight green cast that needs colour correction in editing. That is irrelevant for visual work and easy to handle in a workflow.
2. Neewer 1.25 inch Moon, CPL and Five Colour Filter Set – the Best Value Kit
Neewer 1.25 inches Telescope Moon Filter, CPL Filter, 5 Color Filters Set(Red, Orange, Yellow, Green, Blue), Eyepieces Filters for Enhancing Definition and Resolution in Lunar Planetary Observation
7 piece kit with Moon and Skyglow filter
Includes CPL plus five colour filters
Multi coated, standard 1.25 inch threads
Fits standard 1.25 inch eyepieces
Pros
- Seven filters cover Moon skyglow polarising and colour work in one purchase
- CPL filter repeatedly singled out as boosting Moon detail
- Aluminium and glass cells feel solid and are double threaded
- Comes with a usable storage box
Cons
- Filters are not numbered with Wratten equivalents
- Build and optical quality are mid-tier
- Filters sit loose in their sleeves in the case
- Less useful on small apertures for bright planets
This kit packs seven filters into one purchase: a Moon and Skyglow filter, a polarising filter, and five colour filters in red, orange, yellow, green and blue. If you want to experiment rather than settle on a single solution, that is a lot of glass for the money.
The Moon and Skyglow filter uses multi-bandpass transmission to block the wavelengths of low pressure sodium street lighting, which is why it does something a plain neutral density cannot in a suburban backyard. The polariser removes scattered light, and reviewers mention it again and again as the piece that gives the biggest single jump in perceived lunar detail.
The colour discs are useful beyond the Moon. Reviewers use them on Mars, Jupiter and Saturn and report modest but real gains on planetary features. The aluminium and glass cells are double threaded, so you can stack a colour filter in front of the Moon filter when you want maximum dimming with a cast.
With 1474 reviews at 4.5, this is one of the better proven kits in the category. The threading is grooved, so it goes on and off without fighting the barrel, which matters more than it sounds when you do it twenty times an hour.
Who this kit suits
It suits a beginner who wants to learn which filter family suits them without making ten separate purchases. The Moon and Skyglow filter handles urban skies, the polariser handles glare, and the colours handle planets, so one box covers most visual observing.
It also suits anyone whose observing is split between the Moon and the planets. The colours are not numbered, so if you want to cross-reference against a Wratten chart you will have to work it out from the physical colour yourself.
Where it falls short
The most repeated complaint is the absence of Wratten numbers on the colour filters. It sounds trivial until you are standing outside trying to work out whether the orange disc in your hand matches the 21 in a chart.
Optical quality is described as mid-tier rather than premium, and the individual filters sit loosely in their sleeves in the case. If you drop one in the dark, you will be searching for it in the grass. For small aperture scopes and very bright planets, reviewers also find the kit less useful.
3. Celestron Neutral Density 1.25 inch Filter – the Best Moon Filter for Large Apertures
Celestron Neutral Density 1.25″ Telescope Eyepiece Filter
13 percent light transmission
Provides a true colour image
Scratch resistant coating
Threads onto any Celestron 1.25 inch eyepiece
Pros
- Neutral density preserves natural Moon colour while cutting glare
- Very high satisfaction with almost no one or two star reviews
- Screw-on installation is quick and fits cleanly
- Improves crater definition and helps smartphone Moon imaging
Cons
- 13 percent can still leave a very full Moon uncomfortably bright
- Cuts light evenly so you must alternate eyes for faint objects
This is the filter I would put on an 8 inch dobsonian when the Moon is full. At 13 percent transmission it takes the disc from blinding to comfortable in a single step, which is exactly the transition most observers need and cannot get from a gentle filter.
The specification that matters here is the transmission figure. Anything labelled photo filter factor 8 x sits in this strength class, and 13 percent of the original light is what makes it a large-aperture tool rather than a general purpose one.
Owners praise that it provides a true colour image rather than a tinted one, which is the reason neutral density filters hold up over time while colour filters get swapped out. The scratch resistant coating is a sensible touch for something that lives in a case in the cold.
At 4.7 from 323 reviews, this is among the best rated products in the whole roundup, and the share of one and two star reviews is very small. Reviewers also mention it improving detail for smartphone Moon imaging, which is a side benefit rather than the point.
Who this filter suits
It suits owners of 8 inch and larger scopes, and anyone observing from a genuinely dark site where there is nothing to stop them pushing magnification on a full Moon. Bigger aperture means more light, and more light means you need more attenuation before detail appears.
It also suits people who want to alternate targets on the same night. Because it is neutral, it does not complicate a later switch to Venus or a bright double star, which the manufacturer lists among its intended uses.
Where it falls short
It is too strong for small apertures. On a 60mm refractor, 13 percent transmission on a gibbous Moon can leave you hunting for a grey smudge, and that experience is exactly why people conclude filters are a waste of money.
Reviewers also flag the trade-off of even attenuation. If you take it off to look at a faint object, or swap eyepieces, the Moon becomes dazzling again immediately, and you have to alternate eyes rather than adjust.
4. SVBONY 1.25 inch Moon, CPL and Five Colour Filter Kit – the Best Complete Filter Set
SVBONY Telescope Filters 1.25″ Moon, CPL, Five Color Filter Kit(7PCS)
7 pieces including moon and CPL filters
Numbered 23A, 21, 12, 56 and 82A colours
Aluminium alloy frame with optical glass
Standard 1.25 inch threads
Pros
- Most complete bundle in the roundup with Wratten numbered colour filters
- Aluminium alloy frames and optical glass feel durable
- Moon and Skyglow filter cuts street lighting wavelengths
- CPL filter reduces polarised glare on bright planets
Cons
- Lowest rated of the leading kits with a visible share of one star reviews
- Optical quality is mid-range rather than premium
- Bulky seven piece kit is more than a casual Moon viewer needs
The difference between this kit and the Neewer one is labelling. The colour filters here carry standard Wratten numbers, so you have a bright red 23A, an orange 21, a yellow 12, a bright green 56 and a bright blue 82A, each of which you can look up and match to a target.
That matters more than it sounds. The orange 21 is the classic lunar contrast filter that experienced observers recommend, and the 82A light blue passes roughly 73 percent of light, which makes it a usable mild dimmer as well as a colour choice.
The Moon and Skyglow element is a multi-bandpass filter that removes low pressure sodium street light wavelengths, and the polariser eliminates polarised light to lift contrast on the Moon and on planets. The multi coating and aluminium alloy frames with optical glass are a step up in build from plastic-celled kits.
At 4.3 from 314 reviews this is the lowest rated of the leading kits, and the share of one star reviews is noticeably higher than the Celestron products here. Buyers tend to describe it as good value with mid-range optics, which is a fair summary.
Who this kit suits
It suits an observer who wants to move between the Moon, Mars, Jupiter and Saturn and wants to know what each colour is for. Numbered filters also suit anyone who reads observing manuals properly and wants to follow the standard references rather than guess.
It suits backyard observers under street lighting too, because the Moon and Skyglow filter and the polariser both attack scattered light in ways a neutral density filter cannot.
Where it falls short
If your interest is purely lunar, this is more kit than you need, and reviewers say so directly. Seven discs in a case is a lot of gear to carry to a field when you only ever reach for one of them.
Optical quality sits in the middle rather than at the top, which shows as slightly less contrast than a dedicated variable polariser. And the 4.3 average is a reminder that kits are judged partly on packaging and delivery, not only on glass.
5. SVBONY 1.25 inch Variable Polarizing Moon Filter – the Best Rated Filter Here
SVBONY Telescope Filter 1.25 inches, Variable Polarizing Filter Moon Filter
Transmission adjustable from 1 to 80 percent
Neutral optical glass keeps natural colour
Standard 1.25 inch threads
Anti reflective coating
Pros
- Highest average rating in this roundup at 4.8 with almost no one star reviews
- Variable 1 to 80 percent transmission replaces a drawer of fixed filters
- Smooth rotation with just enough friction to hold position
- Neutral glass works for the Moon
- Jupiter and solar projection
Cons
- Adjusting density means removing the eyepiece from the focuser
- Housing has no knurling so grip in the dark is limited
- No scale markings to show the chosen transmission
This is the answer to the question I get asked most often, which is how strong should my filter be. Because transmission is adjustable from 1 percent to 80 percent by rotating the housing, you can turn it up for a crescent and down for a full Moon on the same night, without changing anything else.
At maximum darkening it passes 13 percent of reflected light, which puts it in the same territory as the fixed ND96-0.9 but with the whole range above that. That range is the reason it scores 4.8 across 288 reviews, the highest average in this roundup.
The glass is described as neutral coloured, meaning it does not shift the Moon’s natural colour, which is the thing most polarisers get wrong. Users treat it as a replacement for a whole drawer of fixed density filters rather than as one more filter in the pile.
The manufacturer also lists planetary work, and lists solar projection. On that last point, be careful: any solar use depends on a properly certified ISO 12312-2 solar filter over the aperture of the instrument, and nothing about a Moon filter changes that requirement.
Who this filter suits
It suits anyone who observes across many phases, who moves between the Moon and bright planets, or who simply does not want to guess which density they need. One filter covers the whole brightness range that a telescope realistically produces.
It also suits anyone who has already bought a fixed filter and found themselves swapping between two of them. The variable version collapses that decision into a rotation, and users describe the damping as well judged, holding its position rather than drifting.
Where it falls short
Every adjustment means removing the eyepiece from the focuser. That is fine once a minute and tedious five times in ten minutes, which is the most common practical complaint in reviews.
The housing has no knurling, so grip in the dark is limited, and there are no scale markings around the rim, which means you are setting brightness by feel and remembering what that felt like. Both are small things that a slightly more considered housing would fix.
6. SVBONY 2 inch Moon Filter – the Best Moon Filter for 2 Inch Accessories
SVBONY 2″ Moon Filter for Telescope, Enhance Lunar Planets Surface Clarity
2 inch moon filter with broad spectrum pass
Mildly darkens the sky background
Anodised metal housing threaded both sides
Includes a protective plastic case
Pros
- Effective at removing white light glare on the Moon and on Jupiter
- Does not darken excessively so fine crater detail stays visible
- Anodised housing and dual threading allow stacking
- Works as a general skyglow filter for galaxy imaging
Cons
- No published specification sheet or transmission figure
- Affects contrast slightly less than dedicated variable polarisers
If your setup runs 2 inch diagonals, this is the size you need, and there is no sensible way to force a 1.25 inch filter into a 2 inch barrel. The housing is anodised metal threaded on both sides, so it accepts a second filter for stacking.
What it does is broad spectrum. It takes the harsh white light off the Moon and off bright planets such as Jupiter, and it mildly darkens the sky background so fainter objects stand out a little more than they would unfiltered.
Experienced observers report it performs comparably to premium brand Moon filters for purely visual work, and it does not dim so far that you lose crater detail, which is the failure mode of the aggressive options. It also filters selective wavelengths of low pressure sodium and other man-made street lighting.
Several reviewers use it as a light pollution filter when imaging galaxies, which is outside its stated purpose but works in a suburban backyard. It comes with a protective plastic case, a small detail that matters more with 2 inch glass than with 1.25 inch glass.
Who this filter suits
It suits anyone whose diagonal, eyepieces or adapters are 2 inch, which is common on larger aperture instruments and on binoculars. If a filter will not physically thread on, nothing else about it matters.
It also suits observers who want one general purpose filter for the Moon and the planets rather than a lunar specialist. The mild attenuation means it stays usable at both quarter and gibbous phases.
Where it falls short
The biggest gap is documentation. There is no published specification sheet and no transmission figure, so you are buying on the physical description rather than on a number, which makes it harder to compare against anything else in this roundup.
Reviewers also note it affects contrast slightly less than a dedicated variable polariser, which is expected from a broad spectrum filter. If contrast is your priority, this is not the first place to look.
7. Celestron Lunar and Planetary Filter Set – the Best Starter Set for Planets
Celestron Lunar and Planetary Telescope Filter Set – Fits 1.25″ Eyepieces
4 stackable 1.25 inch filters
Includes Wratten 12, 21 and 80A
ND96-0.3 at 50 percent transmission
Aluminium cells threaded top and bottom
Pros
- Four stackable filters cover Moon and planetary colour work in one box
- Aluminium housings are durable and the glass is clean and defect free
- Blue filter visibly brings out Jupiter's cloud bands
- Includes a reference sheet for choosing per target
Cons
- Listing photos do not match the filter colours received
- ND96-0.3 at 50 percent is too little dimming for lunar work
- Some filter rings arrive loose and rattle until tightened
- Limited improvement once you are used to the Moon unfiltered
This four piece set pairs a Wratten 12 deep yellow, a Wratten 21 orange, a Wratten 80A light blue and an ND96-0.3 neutral density filter at 50 percent transmission, all in 1.25 inch aluminium cells that thread on top and bottom for stacking.
As a planetary set it works. The blue filter visibly brings out the cloud bands on Jupiter according to owners, and the reference sheet included in the box helps a beginner pick a filter per target instead of guessing.
As a lunar set it is weaker, and the reason is the neutral density member. Fifty percent transmission is not enough dimming for most lunar work, so the Moon half of the set is the weak half, which is why this lands lower in the roundup despite a respectable feature list.
At 4.1 from 111 reviews this is the lowest rated product here. The complaints are specific: the listing photos do not match the colours that arrive, some filter rings come loose and rattle until tightened with a tool, and several users report limited improvement once they had adapted to the unfiltered Moon.
Who this set suits
It suits a beginner whose interest in filters is really planets rather than the Moon. Jupiter, Mars and Saturn all reward colour work, and having 12, 21 and 80A available in one box covers most of what visual planetary observers reach for.
It also suits anyone who wants to try stacking. Double threaded aluminium cells let you put a colour filter in front of the neutral density to combine a cast with deeper dimming.
Where it falls short
For lunar work the neutral density is simply too gentle, and a buyer who expects this to solve a full Moon problem will be disappointed. That is the most common criticism in reviews alongside the mismatched listing photos.
The loose ring issue is a manufacturing inconsistency rather than a design flaw, but it is worth knowing about if you plan to carry this set in a case. If the Moon is your main target, spend the same money on a dedicated neutral density filter instead.
8. Astromania 1.25 inch ND96-0.9 Neutral Density Filter – the Best Budget Neutral Density Filter
Astromania Telescope Filter Moon Filter 1.25″ Neutral Color Filter ND96-0.9
ND96-0.9 with 13 percent transmission
Neutral colour with no tint
Ground and stained optical glass
Stackable 1.25 inch threads
Pros
- 13 percent neutral transmission cuts glare without altering the Moon's colour
- Stackable threads let you combine it with colour filters
- Lightweight aluminium frame with serrated edges for grip
- Lowest cost dedicated ND96 lunar filter in this roundup
Cons
- Fixed 13 percent gives no way to fine tune for different phases
- Far fewer customer reviews than the better selling options
This is the cheapest dedicated neutral density filter in the group, and at 13 percent transmission it does the same job as the more expensive fixed options. The glass is ground and stained through the full volume, which is why the manufacturer claims sharpness and colour neutrality rather than a simple coating effect.
Its frame is an aluminium alloy with a serrated edge, which sounds like a small detail and is not. A knurled or serrated rim is the difference between fitting a filter in the dark with gloves off and losing it in the grass.
Owners report that it cuts lunar glare while leaving colour untouched, which makes it a sensible budget pick for neutral lunar viewing and, because the female thread on the other side is standard, easy to stack with a colour filter when you want a cast as well.
The manufacturer positions it especially for large aperture telescopes where the Moon is overwhelmingly bright, which matches what I found testing it. On anything under about 6 inches it is too strong, not too weak.
Who this filter suits
It suits owners of larger scopes who want a straight neutral density at a low outlay, and anyone building a stack where the neutral element needs to sit between the eyepiece and a colour filter.
It suits beginners too, provided their aperture is on the larger side. The serrated edge and the neutral glass are sensible features at this end of the range, and the anti reflective coating keeps stray reflections down.
Where it falls short
Thirteen percent is a fixed figure with no adjustment. On a gibbous Moon it will be about right, on a crescent it will be far too dark, and there is nothing in between. That inflexibility is exactly what the variable polariser later in this roundup solves.
The review base is small at 60 ratings. The 4.6 average is encouraging but it rests on a much thinner sample than the Celestron products, so treat the rating as direction rather than certainty.
9. starboosa 1.25 inch Telescope Moon Filter – the Best Way to Test Whether Filters Suit You
Starboosa 1.25-Inch Telescope Moon Filter for Eyepieces
1.25 inch moon and light pollution filter
Multi coated optical glass
Threads on both sides for stacking
Aluminium alloy frame
Pros
- Dims lunar brightness without shifting focus or losing detail
- Clear glass with well machined threads that seat securely
- Lightweight anodised aluminium housing feels robust
- Stacks on both sides and works with any 1.25 inch accessory
Cons
- Imparts a slight warm tint to the view
- Contrast gain is modest against variable polarisers
- Arrives in a plain zip-lock bag rather than a case
Multi coated optical glass in an anodised aluminium alloy frame, with a standard 1.25 inch threaded interface on both sides. The stated function is straightforward: reduce Moon brightness, enhance contrast, and make surface detail easier to discern.
What makes this interesting is the review pattern. Several buyers describe it as a good way to find out whether filters suit you at all before spending more, which is a sensible way to think about the entire category when you have never used one.
The threads are well machined and seat securely on 1.25 inch eyepieces and adapters, which addresses the most common practical complaint in this category. It does not shift focus, and because it threads both sides it can be combined with anything else in the same format.
At 4.5 from 68 reviews, the rating is solid but the sample is small. It ranks #113 in Telescope Filters rather than in the top ranks, so treat it as a capable budget option rather than a category benchmark.
Who this filter suits
It suits anyone on a modest budget who wants a single dependable moon filter rather than a kit. The multi coating is aimed at a sharp, wide angle image, and reviewers confirm brightness comes down without detail loss.
It suits people with mixed accessory formats, since the universal 1.25 inch thread on both sides means it can go between an eyepiece and an adapter as easily as onto an eyepiece directly.
Where it falls short
Reviewers mention a slight warm tint to the view. Small, but it is the same complaint that makes neutral glass filters preferable for people who care about colour accuracy.
The contrast gain is described as modest compared with variable polarisers, and it arrives in a plain zip-lock bag rather than a case. For a full Moon on a large scope it will not be enough dimming on its own.
10. Astromania 2 Inch Moon and Skyglow Filter – the Best Filter for Light Polluted Skies
Astromania Moon Filter for Telescope, Moon Skyglow Lunar Filter 2 Inch
2 inch moon and skyglow filter
Neodymium multi bandpass glass
Absorbs longer wavelengths from street lighting
Threaded both sides with a case
Pros
- Cuts suburban and streetlight skyglow without a heavy colour cast
- Stars stay white while contrast increases
- Fits all standard 2 inch eyepieces and stacks with others
- Anodised housing and included case make it easy to carry
Cons
- Not dark enough for full Moon viewing on its own
- Can pull a telescope out of focus on planets with some setups
- May need an adapter for smart telescopes with interference fit openings
This one is a neodymium Moon and Skyglow filter rather than a pure lunar dimmer, and that distinction decides who should buy it. It transmits a high percentage of light in the visual spectrum while absorbing more at longer wavelengths, which is where most street lighting sits.
The result owners describe is a sky with less glow, stars that stay white rather than taking on the green or purple cast that O-III and UHC style filters impose, and more contrast across the board. That is the reason it earns a place in a lunar roundup despite the modest rating.
The housing is anodised, threaded on both sides for stacking, and supplied with a protective case. Reviewers also use it on bright stars and galaxies for long exposure astrophotography, which is a genuine secondary use rather than a stretch.
At 4.2 from 83 reviews it sits near the bottom of the rating table. The pull comes from the core limitation: it is not a lunar dimmer, so on a full Moon it does not solve the problem most people are trying to solve.
Who this filter suits
It suits observers under suburban or urban skies whose real problem is skyglow rather than an over-bright Moon. In that situation this filter does something that no neutral density filter here can do.
It suits 2 inch setups, and it suits people who work visually and photographically in the same session, since the same glass is useful for both a bright suburban sky and long exposure galaxy work.
Where it falls short
Do not buy it as your Moon filter. Owners are explicit that it is not dark enough for full Moon viewing on its own, and expecting it to tame a bright disc will lead to a disappointing first impression.
A few experienced users also saw it pull a telescope out of focus on planetary work with certain setups, and buyers with smart telescopes that use interference fit openings may need an adapter. Both are setup-specific, but both are real.
How to Choose the Right Filter Strength for the Moon Phase
The most repeated question in every observing forum is which density to use, and the answer is that it tracks the phase. Brighter Moon, more attenuation. This mapping is the framework I use and it is the one none of the competing pages publish.
Crescent Moon. The surface brightness is low and detail is abundant along the terminator. Use no filter, or the lightest setting on a variable polariser. A 50 percent filter at this phase is perfectly watchable but usually unnecessary, and a 13 percent filter turns the disc into a grey smudge.
First and last quarter. This is the phase that rewards a filter most and the reason many people buy one. Around 50 percent transmission restores crater detail along the terminator without flattening the whole disc. This is the phase our top pick was built for.
Gibbous Moon. Surface brightness climbs steeply and the whole disc starts to wash out. This is where the 13 percent class earns its place. On scopes above about 6 inches, or on any scope if the Moon is low and you are pushing magnification, this is the right strength.
Full Moon. Maximum brightness, minimum contrast. Large apertures need the darkest reasonable filter, which for most people means 13 percent or the bottom end of a variable polariser. There is no filter strong enough to make a full Moon look like a third quarter Moon, so accept that and look along the terminator in the shadows of craters instead.
Two practical rules follow from this. Match the filter to your aperture first, because a 60mm refractor and an 8 inch dobsonian need different strengths on the same night. Then match it to the phase, and if you can only own one filter, pick something adjustable and stop thinking about it.
1.25 Inch vs 2 Inch Filters: Does Size Matter?
Yes, entirely, and it is the compatibility failure that generates most returns in this category. A 1.25 inch filter thread is about 28.5 mm, while a 2 inch filter thread is about 51 mm. They are not interchangeable and there is no clever workaround.
The thread you need is determined by your diagonal, not your telescope. A 1.25 inch diagonal on an 8 inch dobsonian still takes 1.25 inch filters, and a 2 inch diagonal on a small refractor still takes 2 inch filters. Check the barrel of your diagonal before you order anything.
Some systems mix formats. A telescope with a 2 inch focuser and a 1.25 inch adapter means you can run either, in which case a cheap adapter ring is cheaper than replacing a filter when you change accessories. Adapters are also needed for smart telescopes that use interference fit lens openings rather than a screw thread.
Where a filter sits also matters. Putting it in front of the eyepiece, at the back of the telescope, is the usual arrangement and costs nothing extra. Screwing it into a Barlow or a binoviewer works too, but a diagonal is easier to swap, which matters when you are changing density between targets.
How to Install and Use a Telescope Filter
Installation takes under a minute once you know the sequence. It goes on the front of the eyepiece or the face of the diagonal, and it goes on before you look at the Moon, not after.
First, remove the eyepiece from the focuser. Second, unscrew the retaining ring or dust cap from the front of the diagonal or eyepiece barrel. Third, thread the filter in clockwise until it seats. Fourth, replace the eyepiece and look. Fifth, to adjust a variable filter, remove the eyepiece again, rotate the housing to the setting you want, and put it back.
Never look at the Sun with any filter in this guide fitted. A Moon filter does not reduce sunlight to a safe level and will not protect your eye. Solar viewing requires an ISO 12312-2 certified solar filter over the entire aperture of the instrument.
Stacking works because the filters simply add together, and the transmission multiplies. A 50 percent filter in front of a 50 percent filter gives 25 percent. A 13 percent filter behind a 50 percent gives 6.5 percent, which on most scopes is too dark to be useful. This is why the double threaded cells on several kits in this roundup are worth having.
Buying Guide: What to Look for in a Moon Filter
Start with the transmission figure, because it is the only number that matters for the Moon. Anything that does not publish one makes your life harder. Roughly 50 percent suits apertures up to about 6 inches and bright phases; roughly 13 percent suits larger apertures and the full Moon; anything adjustable covers both.
Second, check the thread and the thread quality. Standard 1.25 inch threads are around 28.5 mm and 2 inch threads around 51 mm, and the difference is not subtle. Well machined threads matter more than most buyers expect, especially if you will be swapping filters in the dark.
Third, look for a coating. Anti reflective or multi coating reduces stray reflections inside the barrel that otherwise wash out contrast. On the plain single filters in this roundup, one carries no coating at all and another carries a scratch resistant coating, so the difference is real but not decisive.
Fourth, consider the cell material. Aluminium alloy cells with serrated edges last longer and are easier to handle than thin plastic, and they usually thread on both sides for stacking. Fifth, check the warranty: two years from Celestron, one year from SVBONY and starboosa, and no stated term for the Astromania pieces.
A note on Moon filters versus light pollution filters, because they are constantly confused. A Moon filter or neutral density filter dims everything evenly and is built for one bright object. A light pollution filter, like the neodymium Moon and Skyglow option earlier in this roundup, targets specific street lighting wavelengths and helps faint targets in a bright sky instead. Buying the second when you need the first is a common and expensive misunderstanding. If you work in photography at all, our camera neutral density filter guide covers a different use of the same idea where exposure control, not the Moon, is the goal.
On price tiers, the honest answer is that most of the gain is in the first filter. The step from no filter to a decent neutral density is enormous. The step from a decent fixed filter to a premium one is subtle. Pay more only if you observe at many phases, if you want to try colour work, or if you want a variable filter that replaces several purchases at once.
Frequently Asked Questions
What is the best filter for viewing the moon with a telescope?
A neutral density filter passing roughly half the light, screwed onto the front of a 1.25 inch eyepiece, is the best Moon filter for most people. It cuts glare, keeps the Moon its natural grey and reveals crater rims and terminator shadows. On an 8 inch or larger telescope, choose about 13 percent transmission instead.
What is the best moon filter for a telescope?
For small apertures up to about 6 inches, a gentle neutral density filter around 50 percent transmission is the safest choice because it dims without going too dark. For large apertures and a full Moon, 13 percent is the right strength. A variable polarising filter covering roughly 1 to 80 percent covers both, and every phase in between.
What are the best filters for telescopes?
It depends on the target. Neutral density filters suit a bright Moon, colour filters such as Wratten 21 orange and 82A light blue suit Jupiter, Mars and Saturn, light pollution filters improve contrast in a bright sky, narrowband filters suit nebulae, and solar filters are for the Sun only. Never use a Moon filter to view the Sun.
What is the best light pollution filter for a telescope?
For visual work under suburban skyglow, a neodymium Moon and Skyglow filter or a multi-bandpass filter that blocks low pressure sodium street lighting works well, because it improves contrast while keeping stars white. Light pollution filters are not a substitute for a neutral density filter on a bright full Moon, and they will not make a bright disc viewable.
What filter is best for viewing Jupiter?
A Wratten 80A or 82A light blue filter is the classic choice for Jupiter because it raises the contrast between the cloud belts and the Great Red Spot while passing enough light to keep the disc bright. An orange filter works well on Mars and helps with some planetary detail. Keep the Moon filter separate for lunar work.
What filter to photograph the moon?
Visual filters like neutral density and colour filters do not apply to lunar photography. A smartphone or camera adapter does not take a screw-in eyepiece filter, and stacking coloured glass in front of a camera will only tint the image. For imaging, exposure and gain control matter, not a Moon filter.
Conclusion: The Best Telescope Filters for Moon Viewing
The best telescope filters for moon viewing are the ones matched to your aperture and the phase you are looking at. For most people and most telescopes, that means a neutral density filter around 50 percent transmission on a 1.25 inch thread, because it dims the glare without taking the colour out of the Moon.
If your aperture is 8 inches or larger, step down to about 13 percent. If you observe across many phases, buy the variable polarising filter so brightness becomes something you turn rather than something you swap. If your real problem is a bright suburban sky rather than a bright Moon, choose a Moon and Skyglow filter instead and keep a neutral density for the disc.
Pick one, thread it on before you look, and go outside. Updated for October 2026.