A small tube whose only job is to watch one star · review
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.
The listing publishes the aperture, the focal length and the limit: 60 mm, 240 mm, for main telescopes up to 1500 mm of focal length. Those are the three numbers guiding software asks for.
A helical focuser with a brass compression ring and two thumbscrews, 48 mm of total focus range including 10 mm of micro-focus on the helical, plus a scaled drawtube with a locking mechanism. A helical focuser moves the camera in and out without rotating it, so the guide star field does not turn as focus changes.
Pipe clamps, a Synta-style dovetail plate and an adjustable dovetail weight for balance. The focuser collar carries a male metric T-thread for guide cameras and also takes a 1.25-inch eyepiece.
Astromania’s 60 mm FMC guide scope shares the 240 mm focal length and brass ring, and publishes its ring bore. On November 7, 2026 the two cost within $2 of each other.
Back focus. Amazon’s item data gives 907 g (2 lb).
On November 7, 2026, Amazon.com listed it at about $96 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 | 60 mm (2.36 in), fully multi-coated |
|---|---|
| Focal length | 240 mm (9.45 in) · stated for main telescopes up to 1500 mm |
| Mounting method | Pipe clamps and a Synta-style dovetail plate · adjustable dovetail weight |
| Flexure resistance | Zero flexure claimed · secure locking mechanism on the drawtube |
| Focuser type | Helical focuser with brass compression ring and two thumbscrews · 48 mm total focus range including 10 mm of micro-focus · scaled drawtube |
| Back focus | Not published by the maker · male metric T-thread on the focuser collar for guide cameras · accepts a 1.25 in eyepiece |
| Weight | Not published in the listing text · Amazon's item data gives 907 g (2 lb) |
| Amazon reference | B074DRFKS4 |
| EAN | 6970019299846 |
Alstar states up to 1500 mm of focal length. The usual rule is a guide scope of at least a fifth of the main scope's focal length for typical guide cameras; 240 mm sits comfortably for mains of 600 to 1200 mm.
The listing gives 48 mm of total focus range including 10 mm of helical micro-focus, which covers most guide cameras. Back focus is not stated.
Yes, with a 1.25 in eyepiece in the focuser it becomes a straight-through finder.
This model is listed on Amazon.com, at ≈ $96 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 guiding setup for a main telescope up to 1500 mm, also used as a finder
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
≈ $78
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
≈ $98
70 mm (2.76 in) · 400 mm (15.7 in) focal length · helical focuser with brass ring · 90 mm focus range · takes 1.25 in eyepieces
Astromania's GS70 deluxe guide scope: 70 mm aperture and 400 mm focal length, a double helical focuser with brass compression ring and 90 mm of range, pipe clamps, a Synta-style plate and a balance weight.
Best for: Guiding a longer main telescope, where a short guide scope would not resolve the correction
≈ $156
