SVBONY SV230 8-20mm Aspheric Zoom Eyepiece (1.25″ and 2″)

Product Overview

The SVBONY SV230 is an 8–20 mm click-stop zoom eyepiece with both 1.25″ and 2″ barrels. The apparent field runs from 72° at 8 mm to 57° at 20 mm, eye relief is 17–19 mm, and the optics are a fully multi-coated 9-element, 6-group design that includes double-sided aspheric lenses to control edge distortion. It weighs 500 g.

Who It's For

This is a good match if you want one eyepiece that covers medium to high power across the planets, the Moon and brighter deep-sky objects, observe with glasses, or use both 1.25″ and 2″ diagonals.

Key Features & Design

• 8–20 mm zoom with click-stops: repeatable magnification steps that are easy to find in the dark.
• 72° to 57° apparent field: the field widens toward the high-power end, where a wide view helps keep a planet in the eyepiece on an undriven mount.
• 9 elements in 6 groups, including aspherics: double-sided aspheric glass reduces distortion at the field edge; all optics are fully multi-coated with blackened lens edges.
• 17–19 mm eye relief: with an adjustable rubber eyecup, usable with eyeglasses.
• Parfocal across the zoom range: focus holds as you zoom, with at most a small touch-up.
• 1.25″ and 2″ barrels: both included, stainless steel, threaded M28.5 x 0.6 and M48 x 0.75 for filters.
• Dioptrx compatible: SVBONY lists Dioptrx mounting as supported.

Optical Design

Zoom eyepieces trade some field width for convenience, and edge sharpness is where simpler designs give ground. The SV230 uses nine elements in six groups, with double-sided aspheric lenses that SVBONY specifies to suppress distortion toward the field edge. Because the apparent field grows as focal length shortens, the true field shrinks less than it would with a fixed-field zoom when you step up in power.

Recommended Uses

• Planetary and lunar observing: step up through the click-stops until the seeing sets the limit.
• Clusters and brighter deep-sky objects: the 20 mm end gives a moderate-power starting view.
• Double stars: fine-tune magnification to split a pair.

Compatibility and Accessory Notes

• Barrels: 1.25″ and 2″ barrels are both included, so it fits either size of diagonal or focuser.
• Filters: M28.5 x 0.6 thread on the 1.25″ barrel and M48 x 0.75 on the 2″ barrel.
• Camera projection: SVBONY notes an M43 T-mount connection through an M43-T adapter, sold separately.
• Magnification: divide your telescope's focal length by the eyepiece focal length. On a 1000 mm telescope the SV230 gives 50x at 20 mm and 125x at 8 mm.

Good to Know Before You Order

• Size and weight: at 500 g and 60 mm outer diameter it is a substantial eyepiece; balance on lighter alt-az mounts may need adjusting.
• Camera adapter: the M43-T adapter for camera projection is not included.

Frequently Asked Questions

Is it difficult to set up?

No. Choose the 1.25″ or 2″ barrel to suit your diagonal, insert it, and turn the zoom ring to a click-stop. Focus holds across the range with at most a small adjustment.

Can I use it with glasses?

Yes. Eye relief is 17–19 mm and the rubber eyecup adjusts.

Does it take filters?

Yes. 1.25″ filters thread onto the 1.25″ barrel (M28.5 x 0.6) and 2″ filters onto the 2″ barrel (M48 x 0.75).

How does it differ from the SV215?

The SV230 covers 8–20 mm with a field up to 72° and longer eye relief; the SV215 covers the shorter 3–8 mm planetary range in a 1.25″ barrel.

Bottom Line

In short: an 8–20 mm click-stop zoom eyepiece with aspheric optics, a 72° to 57° field and 17–19 mm eye relief, supplied with both 1.25″ and 2″ barrels.