It multiplies the focal length, and the eye relief survives · review
A short 1.25-inch 2x Barlow in CNC-machined aluminum with apochromatic glass, multi-coating, a filter thread and an M42 × 0.75 thread for a camera T-ring.
This is a short 1.25-inch Barlow in CNC-machined aluminum, black anodized, with two large locking thumbscrews. It carries a 1.25-inch filter thread at the bottom and an M42 × 0.75 male thread at the top. On November 7, 2026 it cost $18.99.
Astromania’s listing names a common problem: a camera on a T-adapter often cannot reach focus, because its sensor sits farther back than an eyepiece and the focuser runs out of inward travel. A Barlow moves the focal point outward and solves it. Screw a T-ring for your camera onto the M42 thread and the Barlow becomes the adapter.
On a 700 mm telescope, a 10 mm eyepiece gives 70x; with this Barlow, 140x. On a 900 mm telescope, 90x becomes 180x. Both stay inside what a 90 to 130 mm aperture can use on a good night. That is why 2x is the usual first Barlow, and why the 3x version is meant for shorter tubes.
The optics are described as apochromatic glass, multi-coated with an antireflective internal finish. No element count or glass type is given, so “apochromatic” is a claim rather than a specification.
Two locking thumbscrews hold the eyepiece. They grip well, and they can leave rings on a soft eyepiece barrel over time; the Celestron X-Cel LX 2x uses a brass compression ring instead.
On November 7, 2026, Amazon.com listed it at about $19 from a third-party seller.
Figures as Keepa reported them on the day this page was last updated. Stock and pricing shift without warning.
Prices quoted in this text were read on November 7, 2026. The live price is at the top of the page.
Same aisle, closest price — what the same spend else shows.
| Amplification factor | 2x, stated |
|---|---|
| Element count | Not published by the maker · apochromatic glass stated |
| Barrel size | 1.25 in, for 1.25 in eyepieces from most brands |
| Camera thread | M42 × 0.75 male thread, takes a DSLR or mirrorless T-ring (sold separately) |
| Effect on eye relief | Not published by the maker. |
| Coatings | Multi-coated optics with an antireflective internal finish, stated |
| Body | All-metal, CNC-machined aluminum, black anodized · two large locking thumbscrews · 1.25 in filter thread |
| Weight | Not published in the listing text · Amazon's item data gives 71 g (2.5 oz) |
| Amazon reference | B0140UACM6 |
| EAN | 6970019290379 |
It doubles each one's magnification. With a 25 mm and a 10 mm eyepiece on a 700 mm telescope, you get 28x and 70x alone, and 56x and 140x with the Barlow: four powers from two eyepieces.
That is the use the listing names. A camera's sensor sits behind where an eyepiece would focus; a Barlow moves the focal point outward so the focuser can reach it. A T-ring for your camera screws onto the M42 × 0.75 thread.
2x for telescopes of about 650 mm focal length and up, which already give high power with a 10 mm eyepiece. 3x for short telescopes around 400 to 500 mm. Astromania sells both in the same body; the [3x is here](/reviews/barlow-lenses-astromania-lens/).
This model is listed on Amazon.com, at ≈ $19 at the last reading. Listed is not the same as in stock: availability changes daily, and the buy box shows the live price.
Details checked on November 7, 2026.
A first Barlow that will also carry a camera, on a telescope that struggles to reach focus
Amazon reports what buyers took in the month before this page was last checked: at least 50.
The figure is a floor, rounded by Amazon, and read through Keepa — it says what buyers picked, not what a maker claims.
Specifications: the manufacturer sheet for telescopes and observing optics and the matching Amazon product page. Prices and availability: Keepa. Every figure on this page names its source.
2x Barlow · 2 in barrel · ED glass · multi-coated · 2 in filter thread · 1.25 in adapter included
A 2-inch 2x Barlow in ED glass with multi-coated surfaces, a 2-inch filter thread and a 2-to-1.25-inch adapter, so both eyepiece sizes can be doubled.
Best for: A 2-inch focuser and wide-field 2-inch eyepieces that no 1.25-inch Barlow can take
≈ $63
3x Barlow · 1.25 in · apochromatic glass · M42 × 0.75 male thread · 1.25 in filter thread
A short 1.25-inch 3x Barlow in CNC-machined aluminum with apochromatic glass, multi-coated optics, a 1.25-inch filter thread and an M42 × 0.75 thread that takes a camera T-ring.
Best for: A short-focus telescope that needs planetary magnification, or a camera that cannot otherwise reach focus
≈ $24
2x Barlow · 1.25 in (31.8 mm) · two-lens design · for observing and photography
Bresser's 2x Barlow in a 1.25-inch (31.8 mm) barrel, described on Amazon.com as a two-lens design for observing and photography, with a black lens cell and silver barrel.
Best for: An owner of Bresser eyepieces who wants a matching 2x and accepts a thin specification
≈ $98
