SVBONY SV190 18mm 1.25″ Ultra Flat Field Eyepiece

Product Overview

The SVBONY SV190 18 mm is a 1.25″ ultra flat field eyepiece with a 65° apparent field of view and 20 mm of eye relief. Its 8-element, 5-group fully multi-coated design keeps stars sharp from the centre to the edge, and its 23.4 mm field stop gives a wider view than typical Plössl eyepieces. The barrel takes standard M28.5×0.6 filters, and an M42×0.75 thread under the eyecup allows a camera to be attached for eyepiece projection.

Who It's For

This is a good match if you want a low-to-medium power 1.25″ eyepiece with a wide, flat field for deep-sky scanning, the full lunar disc and wide double stars, with eye relief comfortable enough for glasses.

Key Features & Design

• 65° apparent field at 18 mm, wider than a standard Plössl.
• 20 mm eye relief with a rubber eyecup.
• 8 elements in 5 groups, fully multi-coated.
• Flat field: sharp from centre to edge.
• M42×0.75 thread under the eyecup for camera connection.
• Lightweight, durable build.

Optical Design

The eight-element layout includes a field-flattening group, which is what keeps stars in focus out to the 23.4 mm field stop. At 18 mm and 65°, the true field in your telescope is 65° divided by the magnification (telescope focal length ÷ 18 mm), so it frames large clusters and nebulae that a narrower eyepiece crops.

Recommended Uses

• Deep-sky observing: open clusters, larger nebulae and galaxies.
• Whole-Moon views at moderate power.
• Afocal or projection photography via the M42 thread under the eyecup; SVBONY notes it can be matched with the SV406P for scenery.

Compatibility and Accessory Notes

• Barrel: 1.25″ for 1.25″ focusers, diagonals and 2″-to-1.25″ adapters.
• Filter thread: M28.5×0.6.
• Camera thread: M42×0.75 under the eyecup.
• Companion focal length: SVBONY makes the SV190 in 10 mm as well (60°).

Good to Know Before You Order

• 1.25″ only: no 2″ skirt.
• Weight: SVBONY does not publish a weight for the 18 mm.

Frequently Asked Questions

Is it difficult to set up?

No. It slides into any 1.25″ focuser or diagonal and is held by the thumbscrew.

Can I attach a camera?

Yes. Remove the eyecup to reach the M42×0.75 thread.

How wide is the view?

65° apparent field with a 23.4 mm field stop.

Is it good with glasses?

SVBONY describes the 20 mm eye relief as comfortable for eyeglass wearers.

Bottom Line

In short: an 18 mm, 65° flat field 1.25″ eyepiece with 8-element FMC optics, 20 mm eye relief and an M42 camera thread, for wide, sharp deep-sky and lunar views.