SVBONY SV165 40mm Mini Guide Scope
- 40mm Aperture
- 160mm Focal Length (f/4)
- Accepts 1.25" and T2-Threaded Cameras
- 12.5mm Back Focus
- Weighs 449.8g (15.87oz)
The Svbony SV165 Mini Guide Scope combines a 40mm aperture with a fast f/4 focal ratio to deliver bright guide star images for precise autoguiding. Its 160mm focal length provides a wide field of view suitable for most imaging setups, while the fully multi-coated 2-element lens ensures high light transmission. Weighing just 449.8g and built from durable aluminum, this guide scope adds minimal weight to your mobile astrophotography rig.
The 40mm aperture gathers significantly more light than common 30mm guide scopes, allowing your guide camera to detect fainter stars. This expanded selection of potential guide stars is critical in star-poor regions of the sky. The fast f/4 focal ratio keeps guide exposures short, enabling more rapid guide corrections for sharper final images.
Achieving sharp focus on your guide camera is managed by the front-part focuser, which provides 15mm of travel. Once focused, the 12.5mm of back focus is compatible with many popular guide cameras that have a 1.25" nosepiece or T2 threads.
While both are excellent compact guide scopes, they serve slightly different priorities. Your choice depends on whether you prioritize absolute minimum weight or maximum light-gathering ability.
The 40mm aperture gathers more light than smaller 30mm guide scopes. This allows your autoguider to detect and lock onto fainter stars, giving you more options for guiding in any part of the sky.
Yes, absolutely. The Svbony SV165's 160mm focal length provides a wide field of view that is an excellent match for guiding wide-field refractors. When imaging a large target like the North American Nebula, you'll have no trouble finding a suitable guide star within the guide scope's field.
The SV165 uses a front-part focuser. You achieve rough focus by sliding the front section in or out, which has 15mm of travel, and then lock it in place. Fine adjustments can be made by rotating the objective assembly.
The guide scope is designed for cameras with either a standard 1.25" nosepiece or female T2 (M42x0.75) threads. With 12.5mm of back focus, it's compatible with most compact planetary and guide cameras from brands like ZWO, QHY, or Svbony.
While it can work, a 160mm focal length is very short for guiding a telescope with a 2000mm+ focal length. For planetary imaging, where you need extremely precise guiding to resolve fine detail, a longer focal length guide scope or an off-axis guider (OAG) is generally recommended to achieve a better image scale match.
Weighing just under one pound (449.8g), the SV165 is very lightweight. However, it is heavier than ultra-compact 30mm guide scopes. For small star trackers or mounts operating near their payload limit, you should account for this weight plus the weight of your guide camera to ensure stable tracking.
| Brand | SVBONY |
| Aperture | 40 mm / 1.57 inch |
| Focal Length | 160 mm / 6.30 inch |
| Focal Ratio | f/4 |
| Lens Design | 2-Element, Fully Multi-Coated |
| Focuser Type | Front Part Focuser |
| Focuser Travel | 15mm |
| Back Focus | 12.5mm |
| Camera Connection | 1.25" & T2 |
| Material | Aluminum |
| Surface Finish | Sandblasting oxidation |
| Net Weight | 449.8g / 15.87oz |
| Body Size | 179x114x59mm / 7.05x4.49x2.32 inch |