SVBONY SV48P 90mm f/5.5 Achromatic Refractor Telescope OTA

Product Overview

The SVBONY SV48P 90 is a 90 mm achromatic refractor optical tube with a 500 mm focal length at f/5.5. The air-spaced doublet objective uses ZF4/K9 glass with full multi-coating, and the tube carries a 2″ rack-and-pinion dual-speed focuser with a 1:10 reduction ratio that rotates through 360° for framing.

The tube has a 108 mm outer diameter, a net body weight of 2730 g, and a dovetail plate for mounting. It takes 2″ accessories directly and 1.25″ accessories through an adapter.

Who It's For

This is a good match if you:

• Want a wide-field refractor: 500 mm at f/5.5 frames large star fields, clusters and extended nebulae.
• Want to try deep-sky astrophotography: SVBONY positions the SV48P 90 for imaging, and the rotatable focuser helps with framing.
• Travel with your telescope: a compact tube that rides on light mounts.
• Are choosing a first refractor: no collimation, and ready as soon as it is mounted.

Key Features & Design

• 90 mm f/5.5 achromatic doublet: air-spaced ZF4/K9 objective, fully multi-coated.
• 2″ RAP dual-speed focuser: 1:10 fine focus for precise focusing with eyepieces or a camera.
• 360° rotatable focuser: turn the camera or diagonal without moving the tube.
• Multi-green coated optics: SVBONY specifies them for light transmission and reduced false colour.
• Dovetail plate included: for tripods and equatorial mounts.
• 2″ to 1.25″ adapter: for 1.25″ eyepieces and accessories.

Optical Design

The SV48P 90 uses a two-element, air-spaced achromatic objective. An achromat brings two colours to a common focus and gives sharp, contrasty images across most of the spectrum; at f/5.5 a violet fringe shows around the very brightest objects, which a colour-correction filter such as SVBONY's SV231 reduces. The short focal ratio gives a bright, wide field that suits star fields, clusters and large nebulae.

Recommended Uses

• Wide-field visual observing: the Pleiades, the Double Cluster, the Andromeda Galaxy and Milky Way star fields.
• Deep-sky astrophotography: large nebulae and star fields with a DSLR or astronomy camera.
• The Moon: the whole disc fits easily in the field at low power.
• Daytime nature viewing: with an erecting diagonal.

Compatibility and Accessory Notes

• Eyepieces and diagonals: 2″ directly; 1.25″ through the adapter.
• Cameras: the 2″ focuser accepts camera adapters, and the rotation sets framing.
• Mounting: the included dovetail plate fits tripods and equatorial mounts; at 2730 g the tube suits light mounts.
• Dew control: the tube's outer diameter is 108 mm, the figure for a dew heater strip.

Good to Know Before You Order

• Optical tube only: no mount, diagonal or eyepiece is included.
• SV231 style label: SVBONY's style selector for this listing reads “OTA-SV231 Fringe Killer”; contact us and we will confirm whether the SV231 filter ships with it.
• Package list: SVBONY does not publish a separate contents list for the OTA beyond the dovetail plate and adapter.
• Achromatic optics: some false colour is visible on the brightest targets at f/5.5.

Frequently Asked Questions

Is it difficult to set up?

No. The dovetail plate drops into the mount saddle, and a diagonal and eyepiece or a camera complete it. A refractor needs no collimation.

Can I use it for astrophotography?

Yes. SVBONY describes it as an imaging OTA for deep-sky work, and the rotatable 1:10 focuser helps with focus and framing.

Does the focuser rotate?

Yes, through 360°.

How much does it weigh?

2730 g (96.3 oz) for the tube.

Bottom Line

In short: a 90 mm f/5.5 achromatic refractor with a 360° rotatable 2″ dual-speed focuser and dovetail plate, weighing 2730 g, for wide-field viewing and deep-sky imaging. Add a mount and a diagonal and eyepiece or camera.