Best Barlow Lenses for Planetary Viewing of 2026

Updated September 15, 2026 5 products scored

A Barlow is the least glamorous thing you can put in a telescope and the best deal in the hobby: a small lens that sits in the focuser ahead of your eyepiece and doubles or triples the power of every eyepiece you already own. Point one at Jupiter and the belts sharpen into something you can study. A cheap one dims the view, smears purple along the lunar limb, and leaves the eyepiece rattling in a loose barrel.

I've collected a shoebox of them, and the differences never show up on a spec sheet: a Barlow stretches the eyepiece's eye relief, adds focus travel, and has to sit squarely in the diagonal. We spent four months with 14 of them, 2X and 3X models, on the Moon, Saturn, and Jupiter, plus daylight runs at a chimney across the street.

No Barlow makes a small scope show more than its aperture allows — past about 50x per inch you get a bigger, softer image, not a better one. The picks below are the ones that magnify without punishing the view.

1

Best Overall

Celestron Omni 2X Barlow

Celestron Omni 2X Barlow

92 /100
LBD Score Outstanding

Key details

Weight
2.8 oz
Coatings
Fully multi-coated
Eyepiece Fit
1.25 inches
Magnification
2x
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Three eyepieces become six, which is the honest arithmetic behind every Barlow and the reason we point most people here before they buy another eyepiece. Celestron's Omni 2X is the one we recommend as a default, because 2x is the multiplier most telescopes can actually use on a planet, and the optics are fully multi-coated with blackened edges rather than the bare glass at the bottom of the market.

In the focuser it behaves like a well-machined accessory. The barrel slides into a 1.25-inch focuser or diagonal and accepts any 1.25-inch eyepiece, and the body is threaded for standard 1.25-inch filters, so one moon filter screwed to the Barlow covers your whole collection instead of riding on each eyepiece in turn. On Jupiter and Saturn we got a larger image that stayed crisp, and the extra eye relief it lends a short eyepiece made long looks at the Moon far less tiring.

Where it stops is the ceiling of what your scope can deliver. Doubling the power of your shortest eyepiece is plenty on a long-focal-ratio refractor and too much on a night of rough air, and no Barlow fixes that. What we appreciate is that the useful range is exactly where this one lives, so it stays in the diagonal instead of the case.

Pros

  • Doubles the power of every 1.25-inch eyepiece
  • Fully multi-coated optics with blackened lens edges
  • Filter thread lets one moon filter serve all eyepieces

Cons

  • No T-thread, so it's visual use only
Our verdict

We tell first-time planetary observers to buy this one: a fully multi-coated 2x that doubles every eyepiece without spending more than the eyepieces cost.

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2

Best Budget

SVBONY 2X Barlow

SVBONY 2X Barlow

90 /100
LBD Score Outstanding

Key details

Weight
3.2 oz
Coatings
Multi-coated
Camera Thread
M42 x 0.75
Magnification
2x
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At this end of the price range we expected plastic and got anodized aluminum instead. The SVBONY 2x is the least expensive Barlow in this guide and still arrives with a metal barrel, a blackened interior, and caps on both ends, which is the sort of thing you notice after the lens has lived in a damp accessory box for a season.

The M42 thread on the barrel is why we kept reaching for it. Screw on a T-ring and the same glass that doubles an eyepiece will hang a DSLR off the scope, a feature both Celestron picks leave out. The front element also unscrews and threads directly onto an eyepiece barrel for a lower multiplier, and how much lower depends on the eyepiece rather than on a number in the manual. For a binoviewer or an eyepiece that already sits near your scope's ceiling, that flexibility is worth more than a nicer coating.

Two elements in one group is the spec that separates it from the premium picks, and it shows as a little more color on a bright lunar limb than the apochromatic Celestrons manage. The short body is the other thing to watch: a long eyepiece barrel can bottom out before it seats, so check that yours drops all the way in and that the thumbscrew bites metal. With a short Plössl neither is a problem, and at this price it's easy to treat as the Barlow that lives in the travel kit.

Pros

  • Lowest price of any pick here
  • M42 thread couples a DSLR with a T-ring
  • Front element unscrews for a lower multiplier

Cons

  • Two-element glass shows a little color on bright edges
Our verdict

The bargain of the group: a metal-bodied 2x that couples a DSLR and unscrews onto an eyepiece, as long as you accept two-element glass.

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3

Best 3X for High Power

Celestron X-Cel LX 3X Barlow

Celestron X-Cel LX 3X Barlow

92 /100
LBD Score Outstanding

Key details

Weight
5.3 oz
Magnification
3x
Optical Design
3-element apochromatic
Eyepiece Holder
Brass compression ring
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The Omni above is the safe answer for most scopes; this is the answer when 2x isn't enough. Celestron built the X-Cel LX 3x for owners of fast, short-focal-ratio telescopes, where tripling a mid-power eyepiece lands you in the range the planets reward instead of sailing past it.

The glass is why it costs what it does: three apochromatic elements, fully multi-coated, with blackened edges. In practice the purple fringe that creeps onto a bright lunar limb with cheap 3x glass stays away, and the belts on Jupiter hold their contrast. Around the barrel the details are the ones we want on our own gear — a brass compression ring that clamps the eyepiece without scratching it, a thread that takes 1.25-inch filters directly, and a rubber grip ring that earns its keep when the metal is cold.

The catch is headroom, not quality. Tripling your shortest eyepiece overshoots a long-focal-ratio refractor on all but the steadiest nights, and a soft, dim view is what you get for trying. Matched to a short tube, it delivers the sharpest high-power image in this group, and the optical cell unscrews, which makes cleaning far less nerve-racking than working through a fixed barrel.

Pros

  • Three apochromatic elements hold color together
  • Brass compression ring protects eyepiece barrels
  • Threaded to accept 1.25-inch filters directly
  • Rubber grip ring helps in cold weather

Cons

  • Costs more than any 2x pick here
  • Ships without a case
Our verdict

Buy this when your short-tube scope still has headroom and you want a 3x that keeps contrast on Jupiter instead of smearing it.

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4

Best for Eyeglasses

Explore Scientific 2X Focal Extender

Explore Scientific 2X Focal Extender

90 /100
LBD Score Outstanding

Key details

Weight
9.1 oz
Coatings
Fully multi-coated
Magnification
2x
Optical Design
Telecentric
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A conventional Barlow pushes your eye back from the eyepiece and changes the magnification slightly depending on how far the eyepiece sits in the barrel. The Explore Scientific focal extender solves both at once: its telecentric optics keep the light rays parallel, so the view stays at a true 2x wherever the eyepiece bottoms out, and the eye relief you get is the eye relief you expected.

For anyone who observes in glasses, that predictability is the whole purchase. We like pairing it with a low-power eyepiece — a relaxed 25mm becomes a comfortable high-power view rather than forcing you into a short eyepiece with a pinhole of eye relief. It's fully multi-coated and fits any 1.25-inch focuser or diagonal, but it is 96mm long and 9.1 ounces, the heaviest barrel in this roundup; a solid diagonal takes it without complaint, and a lightweight focuser will notice.

What it can't do is add aperture. Two times is two times, and on an average night a 5-inch scope runs out of sharp detail before this glass does. Buy it for the eye relief and the honest magnification, not for a bigger image than the sky will support.

Pros

  • Telecentric design keeps a true 2x at any spacing
  • Predictable eye relief for glasses wearers
  • Pairs well with comfortable low-power eyepieces

Cons

  • Most expensive lens in this roundup
  • Long and heavy for a small focuser
Our verdict

The one to buy if you observe in glasses: a telecentric 2x that holds its magnification and keeps the view comfortable.

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5

Best Low-Cost 3X

SVBONY 3X Barlow

SVBONY 3X Barlow

89 /100
LBD Score Excellent

Key details

Weight
3.52 oz
Coatings
Fully multi-coated
Magnification
3x
Optical Design
Achromatic
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Tripling the power of a long-focal-ratio refractor is usually a mistake; do it on a short-tube 130mm and the planets finally fill the eyepiece. SVBONY's 3x is built for the second situation, and at this price it's the least expensive way to find out which telescope you own.

Achromatic elements and full multi-coating do the work, and the barrel is metal with a rubber grip ring, a set screw and caps at both ends. We noted very little light loss going through it — the image gets bigger without turning grey — and the blackened interior keeps reflections from washing out the lunar surface.

It's still a budget 3x, and the view softens and dims once the scope is close to its limit, which is the scope talking as much as the glass. Where it earned its spot for us was comfort at high power: the same magnification through this Barlow and a relaxed mid-power eyepiece showed less blackout than a short eyepiece on its own, a trade we didn't expect from an inexpensive extender.

Pros

  • Achromatic, fully multi-coated glass at a low price
  • Less blackout than a short eyepiece at the same power
  • Metal barrel with rubber grip ring and end caps

Cons

  • Set screw can mark eyepiece barrels
Our verdict

A cheap, honest 3x for a short-tube scope, and the least painful way to find out whether your telescope can take the power.

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How We Chose and Tested These Barlow Lenses

Every lens we tested started on paper. We read through 1.25-inch models and sorted them by whether the optics were multi-coated, whether the barrel carried a thread for a camera adapter, whether the optical cell could be unscrewed for lower-power use, and how the price stacked up against simply buying another eyepiece — then ordered 14 of them, roughly half 2X and half 3X.

Those 14 lenses lived with us for four months, mostly in a backyard after dark on a small refractor, a 6-inch Dobsonian, and an 8-inch Schmidt-Cassegrain. Jupiter and Saturn were the main targets, with the Moon's terminator, a few tight double stars, and daytime looks at a brick chimney across the street, where soft edges and stray light show up faster than they do at night.

Each session ran the same way: same eyepiece, swapped from one Barlow to the next without moving the scope, so the comparison was back to back. We racked focus in and out to see how much extra travel each one demanded, and noted when the image dimmed noticeably or a purple fringe crept onto the lunar limb. In the dark we timed how long a swap took with gloves on, wiggled the eyepiece after tightening the screw to see whether it shifted, and checked which lens cells unscrewed cleanly without bottoming out against the diagonal mirror.

Value got the last word. For each lens we compared a barlowed eyepiece against a shorter eyepiece of the same power, and the ones that came closest to matching that view — at a fraction of the cost — were the ones that survived.

How to Choose a Barlow Lens for Planetary Viewing

Match the Multiplier to Your Aperture

A telescope's practical ceiling is roughly 50x per inch of aperture, or about twice the aperture in millimeters, and that's on a good night. Take the power of your sharpest eyepiece, double it, and see where you land. On a 70mm long-focal-ratio refractor, a 2x usually sits near the ceiling and a 3x sails past it. On a 130mm f/5, 3x still has room, which is why the X-Cel LX 3x earns a place here.

The trap is the cheap 5x. Past the ceiling you get a bigger, softer, dimmer image, not more detail, and the lens gets blamed for what the aperture did.

Traditional Barlow or Telecentric Extender

A conventional Barlow is a negative lens that multiplies focal length. The exact factor drifts a little with how far the eyepiece sits from it, and eye relief grows along with the power. A telecentric extender keeps the light cone parallel instead, so 2x stays 2x wherever the eyepiece bottoms out, and the eye relief you get is the eye relief you expected.

If you observe in glasses, or you want repeatable framing for a camera, that steadiness is worth paying for — it's the reason the Explore Scientific extender is in this guide. Otherwise a conventional Barlow does the same job for less.

What the Glass and the Barrel Buy You

At 2x, almost any multi-coated Barlow looks decent in the middle of the field. At 3x the differences show: three apochromatic elements hold color together on a bright lunar limb where two-element glass fringes, so the jump from the SVBONY 3x to the Celestron X-Cel LX 3x is real rather than cosmetic.

Around the glass, a brass compression ring grips an eyepiece barrel without scoring it, blackened interiors keep stray light off the planets, and a rubber grip ring matters more than it sounds on a cold metal barrel. We put more weight on coatings than on finish.

Threads: Filters and Cameras

Two threads matter. A 1.25-inch filter thread on the Barlow's barrel lets one moon filter serve every eyepiece you own, and it's the detail we miss most on a lens that lacks it. An M42 thread on the barrel turns the Barlow into a camera coupler once you add a T-ring, which is what the SVBONY 2x offers.

If you only observe visually, skip the camera thread and put the money into glass. If you want to photograph planets, check that your scope still reaches focus with the extra length in the stack.

Length, Weight, and Focuser Travel

A Barlow adds a couple of inches to the optical path and moves the eyepiece's focal plane. Most refractors and catadioptric scopes with a diagonal take that in stride; some Newtonians run out of inward travel. Weight matters on small focusers too — the Explore Scientific extender is 96mm long and 9.1 ounces, which a sturdy diagonal handles and a lightweight plastic focuser may not.

Test the combination in daylight before you count on it after dark.

Frequently Asked Questions

Final Verdict

The Celestron Omni 2X is what we point most people to first. Two times is the multiplier a typical scope can actually use on a planet, the lens is fully multi-coated with blackened edges, and it costs less than either apochromatic pick here while doubling every eyepiece you own.

If your telescope is a fast short tube with headroom to spare, the X-Cel LX 3x gives the sharper high-power view. If you observe in glasses, the Explore Scientific extender is the one that keeps the view comfortable.