Tele Vue

Tele Vue 2x Barlow 1.25-inch

2× · 1.25" · fully multi-coated

Doubles the magnification of any 1.25" eyepiece, turning a two-eyepiece kit into four useful powers, with Tele Vue optics that add no visible softness.

87/ 100

Polaris Score

The premium pick among the barlows we recommend

From$153

Where to buy

Agena AstroProductsPartnerBest price$153→High Point ScientificCheck price→

Affiliate link — we earn a commission, you pay the same. We rank on fit, not payout.

What problem does this solve?

One Barlow doubles every eyepiece you own.

A Barlow is a negative lens that sits between your eyepiece and the telescope and multiplies the magnification, a 2× Barlow makes a 20 mm eyepiece perform like a 10 mm one. Drop it in front of each eyepiece in your case and you effectively double the number of powers you can reach without buying more glass.

The catch with cheap Barlows is that they trade sharpness for reach: they add colour, dim the view, or soften the edges. The Tele Vue is the reference 2×, its figure and coatings are good enough that the doubled view looks like it came from a shorter eyepiece, not from an add-on.

You need one if

You need one if you have two or three eyepieces and want more high-power options for the Moon, planets and double stars without buying a whole new set.

You can skip it if

You can skip it if you already own a dense ladder of short eyepieces, or observe mostly wide-field deep-sky where extra magnification just dims the target.

How it actually works

What the setup looks like.

A Barlow drops into the light path ahead of the eyepiece. The order matters, and so does where you place it relative to a star diagonal.

Pull the eyepiece

Take the eyepiece out of the focuser or diagonal and set it aside. Nothing else in the setup has to change.

Drop the Barlow in

The 1.25 inch nosepiece goes into the focuser or diagonal exactly where the eyepiece was sitting. Tighten the thumbscrew.

Seat the eyepiece on top

The eyepiece now goes into the top of the Barlow. Any 1.25 inch eyepiece fits, whatever the brand.

Refocus outward

Inserting the Barlow shifts the focus point, usually by a noticeable turn of the knob. Refind focus before judging the view.

Thread filters onto the nose

The filter thread on the Barlow nosepiece lets a Moon or colour filter stay in the train while you swap eyepieces above it.

Placing the Barlow ahead of a star diagonal rather than directly under the eyepiece raises the amplification above 2x, because the added path length increases the factor. Start with it directly under the eyepiece so you always know the power you are observing at.

01Will it fit my setup

Compatibility.

What this accessory works with — check the fit before you check the price.

1.25" focusersAny 1.25" eyepieceRefractorsNewtonians & DobsSCTs & Maks

Note✕Not for 2" eyepieces✕Adds one more optical group

02The numbers

What These Numbers Mean

Magnification factorDoubles power

Halves the effective focal length of any eyepiece you use with it, so a 24 mm behaves like a 12 mm while retaining the 24 mm's comfortable eye relief. It effectively doubles the size of your eyepiece case.

Optical qualityReference

Fully corrected achromatic

Tele Vue Barlows are corrected well enough that they do not visibly soften the view at high power, which is the failure mode of budget Barlows. You can use it with premium eyepieces without giving anything back.

Barrel sizeStandard

1.25 inch

Fits the standard focuser and diagonal size found on nearly every telescope, and works with any 1.25 inch eyepiece regardless of brand.

Where it helps mostHigh power

Planets, the Moon, doubles

Magnification is what those targets reward. On faint galaxies and nebulae, doubling the power spreads the same light over four times the area, so lower power usually shows more.

Optical

TypeBarlow, negative lens

Amplification2×

Fit1.25" barrel

CoatingsFully multi-coated

EffectHalves any eyepiece's focal length

In use

BodyMachined, anodised aluminium

Best onMoon · planets · double stars

Pairs withYour mid- and long-focal eyepieces

AddsOne extra air-glass group

03Before you buy

Good to know.

The honest caveats — the things that save you a return, a bad first night, or a second purchase you didn't need.

It multiplies power, not aperture.

A Barlow can't show more than your aperture resolves, past roughly 50× per inch the image just gets dim and soft. Use it to fill gaps in your power range, not to chase empty magnification.

Barlow your comfortable eyepieces.

The Barlow inherits the eye relief of whatever eyepiece you pair it with, so a long, relaxed eyepiece plus this Barlow gives high power without the pinhole squint of a short eyepiece.

Start at the nominal 2×.

Dropped straight into the focuser it gives about 2×; adding spacing raises the factor. Begin at the marked 2× and you always know exactly what power you are observing at.

04Completes the kit

Related accessories.

The natural partner

A quality mid-focal eyepiece

Pair the Barlow with a comfortable 15–25 mm eyepiece to reach high power with easy eye relief.

For 2" kits

A 2" Barlow or Powermate

If you observe through a 2" diagonal and eyepieces, step up to a 2" amplifier instead.

Keeps the image honest

A good star diagonal

On refractors and SCTs, a quality diagonal makes sure the Barlow's sharp image reaches your eye intact.

Editor’s Take

Ask a long time observer which accessory they would replace last and this one comes up more often than any eyepiece. It is the piece of glass that quietly ended a decades long argument about whether a Barlow costs you sharpness, and for most observers the answer became no. Decades on it is still in the case, still working, still the thing you hand a beginner to show what good glass is actually worth.

— The Skynocular verdict

87/ 100

Tele Vue 2x Barlow 1.25-inch

2× · 1.25" · fully multi-coated · $153

Doubles the magnification of any 1.25" eyepiece, turning a two-eyepiece kit into four useful powers, with Tele Vue optics that add no visible softness.

Agena AstroProductsPartnerBest price$153→High Point ScientificCheck price→