SVBONY 2x Barlow Lens 1.25″ with M42 Threads

Product Overview

The SVBONY F9108A is a 1.25″ (31.7 mm) 2x Barlow lens. It slides into a 1.25″ focuser or diagonal, accepts a 1.25″ eyepiece on top, and doubles the magnification that eyepiece gives on your telescope. The optics are optical glass with a multilayer broadband green coating, set in a black metal housing 7.5 cm (2.95″) long, with an M42 x 0.75 thread for camera use.

Who It's For

This is a good match if you observe the Moon and planets visually and want more magnification from the eyepieces you already own, or if you want a simple way to extend focal length for lunar and planetary imaging with an M42-threaded camera adapter.

Key Features & Design

• 2x magnification factor: a 20 mm eyepiece behaves like a 10 mm, effectively doubling your eyepiece set.
• Multilayer broadband coating: applied to the optical glass to keep light loss low and contrast high.
• All-metal housing: black metal body, 7.5 cm long.
• Standard 1.25″ barrel: fits 1.25″ focusers, diagonals and eyepieces.
• M42 x 0.75 thread: lets the Barlow connect into an M42 (T2) camera train.

Optical Design

A Barlow is a negative lens placed ahead of the focal plane. It lengthens the effective focal length of the telescope, so a 1000 mm telescope works as roughly 2000 mm with this lens at its rated position. Because the focal ratio doubles as well, image scale doubles for a camera and magnification doubles for an eyepiece, while eye relief and the eyepiece's apparent field are largely unchanged.

Recommended Uses

• Lunar and planetary observing: higher magnification on the Moon, Jupiter, Saturn and Mars.
• Double stars: extra power for splitting close pairs.
• Planetary imaging: longer effective focal length for a larger image scale with an M42-threaded camera.

Compatibility and Accessory Notes

• Barrel: 1.25″ (31.7 mm) for 1.25″ focusers and diagonals.
• Eyepieces: accepts standard 1.25″ eyepieces.
• Camera use: M42 x 0.75 thread for M42/T2 camera adapters.

If you are pairing it with a specific camera or adapter, send us your setup and we will confirm the connection with you.

Good to Know Before You Order

• Magnification is limited by conditions: doubling power also enlarges atmospheric turbulence, so the highest combinations work best on steady nights.
• 1.25″ only: it does not accept 2″ eyepieces.
• Weight: SVBONY does not publish a weight for this Barlow.

Frequently Asked Questions

Is it difficult to set up?

No. It goes into the focuser or diagonal like an eyepiece, and your eyepiece goes into the top of the Barlow.

What does 2x mean in practice?

Each eyepiece gives twice its usual magnification. A 25 mm eyepiece on a 1000 mm telescope gives 40x on its own and 80x with the Barlow.

Can I use it for photography?

Yes. The M42 x 0.75 thread lets it sit in an M42-threaded camera train for lunar and planetary imaging.

Bottom Line

In short: a compact 1.25″ 2x Barlow with multi-coated optics and an M42 thread, doubling the magnification of your existing eyepieces for lunar and planetary work.