SVBONY SV165 30mm f/4 Mini Guide Scope with Helical Focuser

Product Overview

The SVBONY SV165 is a 30 mm f/4 mini guide scope for autoguiding a deep-sky imaging rig. Its fully multi-coated achromatic objective gives a 120 mm focal length, and a helical focuser with 45 mm of travel brings the guide camera to focus. The camera end accepts 1.25″ nosepieces and M42 x 0.75 threads, with 26 mm of back focus. The aluminium tube has a sandblasted, oxidized finish, measures 112 mm long, and the scope weighs 342 g.

Who It's For

This is a good match if you image deep-sky targets on an equatorial mount and want a light, compact guide scope that adds little weight to the rig, or if you travel with a small imaging setup and need guiding without a bulky second telescope.

Key Features & Design

• 30 mm f/4 achromat: 120 mm focal length, fully multi-coated, for a wide guiding field with plenty of guide-star choice.
• Helical focuser: 45 mm of travel for fine, repeatable focus on guide stars.
• Dual camera interface: 1.25″ slip-fit and M42 x 0.75 thread.
• Ring bracket with dovetail: two-ring bracket with nylon-tipped thumbscrews for aiming the scope, on a dovetail base.
• UNC 1/4-20 mounting thread: for attaching to other mounting hardware.
• Compact aluminium body: 45 mm tube, 48 mm dew cap, 112 mm overall length, 342 g.

Optical Design

The objective is a fully multi-coated 30 mm achromat working at f/4. A 120 mm focal length paired with a small-pixel guide camera gives an image scale suited to guiding imaging telescopes of short to moderate focal length, and the fast focal ratio keeps guide stars bright at short guide exposures. The 26 mm back focus places the focal plane close to the end of the focuser, which suits dedicated guide cameras.

Recommended Uses

• Autoguiding deep-sky astrophotography with software such as PHD2.
• Portable and travel imaging rigs where weight and length matter.
• Long-exposure imaging on equatorial mounts that benefit from guided correction.

Compatibility and Accessory Notes

• Guide cameras: SVBONY pairs it with the SV305 Pro and other guiding cameras; any camera with a 1.25″ nosepiece or M42 x 0.75 thread fits.
• Mounting: the supplied ring bracket and dovetail fit a finder-style dovetail shoe; a UNC 1/4-20 thread is also provided.
• Back focus: 26 mm.

What's in the Box

• SV165 30 mm f/4 mini guide scope
• Two-ring bracket with dovetail
• Two nylon-tipped thumbscrews
• Screw tool
• Dust cover
• Lens cover

Good to Know Before You Order

• Guide camera sold separately: this listing is the guide scope alone.
• Eyepiece use: SVBONY notes that an extension tube is needed to reach focus with an eyepiece; the scope is designed around a guide camera.
• Dovetail shoe: your telescope or mounting plate needs a finder-style shoe or a 1/4-20 attachment point.

Frequently Asked Questions

Is it difficult to set up?

No. Slide the dovetail into a finder shoe, insert or thread the guide camera, and focus on a bright star with the helical focuser, then lock it.

Which guide cameras fit?

Cameras with a 1.25″ nosepiece or an M42 x 0.75 thread, including the SVBONY SV305 Pro.

What focal length of main telescope does it suit?

Its 120 mm focal length suits guiding short and moderate focal-length imaging telescopes, such as small refractors.

Can I use it as a finder?

Visual use needs an extension tube to reach focus with an eyepiece, per SVBONY.

Bottom Line

In short: a 342 g, 30 mm f/4 guide scope with a 120 mm focal length, helical focuser and 1.25″/M42 camera fit, ready to guide a compact imaging rig once a guide camera is added.