A small tube whose only job is to watch one star · review
SVBONY's SV106 50 mm guide scope: a helical focuser with 8 mm of travel and a lock thumbscrew, up to 30 mm more on a telescoping drawtube, male T-threads, two rings and a 3.5 × 1.18 in dovetail bar.
SVBONY’s 50 mm SV106 uses a helical focuser with 8 mm of travel and a thumbscrew that locks it once focus is set. For guiding, which runs for hours, a focuser that cannot drift is worth having. A telescoping drawtube adds up to 30 mm more for the guide camera.
Two heavy-duty rings with six metal thumbscrews for aiming, and a 3.5-inch by 1.18-inch dovetail bar with five threaded sockets that fits dovetail finder bases. The focuser collar carries male T-threads for guide cameras.
The focal length is not published. Guiding software needs it to compute corrections; find it before setting up.
The SV106 60 mm adds aperture, 35 mm of drawtube travel and a compression ring.
On November 7, 2026, Amazon.com listed it at about $80 from a third-party seller.
Figures as Keepa reported them on the day this page was last updated. Stock and pricing shift without warning.
Prices quoted in this text were read on November 7, 2026. The live price is at the top of the page.
Same aisle, closest price — what the same spend else shows.
| Aperture | 50 mm (1.97 in) |
|---|---|
| Focal length | Not published in the listing. |
| Mounting method | Two heavy-duty rings with six metal thumbscrews · 3.5 in long, 1.18 in wide dovetail bar with five threaded sockets |
| Flexure resistance | Zero flexure claimed |
| Focuser type | Helical focuser, 8 mm of travel, with a lock-down thumbscrew · telescoping drawtube adds up to 30 mm |
| Back focus | Not published · up to 30 mm of additional back-travel for the autoguider · male T-threads on the focuser collar |
| Weight | Not published in the listing text · Amazon's item data gives 771 g (1.7 lb) |
| Amazon reference | B07MPYDYLZ |
| EAN | 0794604984094 |
Guiding runs for hours. A focuser that drifts as temperature changes or the mount slews will soften the guide star; a lock-down thumbscrew holds focus.
The listing does not say. That figure is needed in guiding software; check SVBONY's spec sheet or measure it before configuring.
SVBONY gives 8 mm of helical travel plus up to 30 mm of drawtube back-travel, which covers most guide cameras without extension tubes.
This model is listed on Amazon.com, at ≈ $80 at the last reading. Listed is not the same as in stock: availability changes daily, and the buy box shows the live price.
Details checked on November 7, 2026.
A first guiding setup on a small mount, where a lockable focuser earns its place
Specifications: the manufacturer sheet for telescopes and observing optics and the matching Amazon product page. Prices and availability: Keepa. Every figure on this page names its source.
50 mm (1.97 in) · 200 mm (7.87 in) focal length · helical focuser with brass compression ring · 40 mm focus range
Alstar's 50 mm guide scope: 200 mm focal length, fully multi-coated, a double helical focuser with brass compression ring and 40 mm of focus range, a male T-thread, rings and a Synta-style plate.
Best for: Guiding a main telescope of moderate focal length, and doubling as a wide finder
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60 mm (2.36 in) FMC · 240 mm focal length · helical focuser with brass ring · 80 mm rings for 53 to 79 mm tubes · Teflon inlays
Astromania's 60 mm FMC guide scope: 240 mm focal length, a helical focuser with brass compression ring and 45 mm of range, male T-threads, and two rings of 80 mm bore with Teflon inlays on a Synta-style plate.
Best for: A guide scope whose rings have to clamp a 53 to 79 mm tube without marking it
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60 mm (2.36 in) · 240 mm (9.45 in) focal length · helical focuser with brass compression ring · 48 mm focus range · Synta dovetail
Alstar's 60 mm guide scope: 240 mm focal length, fully multi-coated, a helical focuser with brass compression ring and 48 mm of total focus range, a male T-thread for guide cameras, rings and a Synta-style plate.
Best for: A guiding setup for a main telescope up to 1500 mm, also used as a finder
≈ $96
