SVBONY SV106 50mm f/3.8 Guide Scope with Helical Focuser

Product Overview

The SVBONY SV106 (item F9177A) is a 50 mm achromatic guide scope with a 190 mm focal length (f/3.8) and a built-in helical focuser. It mounts on top of your main telescope with the included rings and dovetail rail and carries a guide camera on the male T-thread of its focuser collar. The tube is 54.5 mm in diameter, 240 mm long, and the optics are fully multi-coated. It also works as a straight-through finder with a 1.25″ eyepiece.

Who It's For

This is a good match if you are setting up autoguiding for deep-sky imaging and want a compact, short-focal-length guide scope that finds guide stars easily, or a finder that doubles as a guide scope.

Key Features & Design

• 50 mm f/3.8 achromat: 190 mm focal length gives a wide field for picking up guide stars.
• Helical focuser with 8 mm travel: knurled fine-focus ring and thumbscrew lock, designed to avoid flexure while focusing.
• 30 mm telescoping drawtube: for coarse focus range.
• T-thread on the focuser collar: accepts guide cameras with a female T-thread.
• Fully multi-coated optics.

Optical Design

The SV106 is a 50 mm achromatic refractor working at f/3.8. For guiding, the short focal length matters more than colour correction: it gives a wide field so a guide star is easy to find, while the helical focuser holds focus without the shift a rack-and-pinion focuser can introduce under a camera's weight.

Recommended Uses

• Autoguiding deep-sky imaging rigs with a guide camera on the T-thread.
• Finder scope with a 1.25″ eyepiece (sold separately).

Compatibility and Accessory Notes

• Mounting: two guide scope rings and a 3.5″ dovetail bar fit standard finder-scope bases.
• Guide camera: male T-thread on the focuser collar for cameras with a female T-thread.
• Eyepieces: 1.25″, sold separately.
• Other styles: SVBONY also lists the SV106 with an SV152 illuminated eyepiece and with an SV905C camera and dovetail. Contact us for those bundles.

What's in the Box

• SV106 50 mm guide scope with helical focuser
• Two guide scope rings
• Dovetail mounting bar

Good to Know Before You Order

• Guide camera and eyepiece sold separately.
• Finder-shoe mounting: the included bar fits a standard finder-scope base on your main telescope.
• Weight: SVBONY does not publish a weight for this item.

Frequently Asked Questions

Is it difficult to set up?

No. Slide the dovetail into your finder base, thread your guide camera onto the T-thread, set rough focus with the drawtube and fine focus with the helical ring, then lock it.

Which guide cameras fit?

Cameras with a female T-thread connect directly to the focuser collar.

Can I use it as a finder?

Yes, with a 1.25″ eyepiece.

How is it different from the SV106 60 mm?

This model is the 50 mm f/3.8 version with 190 mm focal length; the 60 mm is a separate SVBONY product.

Bottom Line

In short: a 50 mm f/3.8 achromatic guide scope with a helical focuser, T-thread camera connection, rings and dovetail, for autoguiding or finder duty.