Half the weight, half the glass, one eye · review
A collapsible pirate-style brass-finished spyglass with a leather-wrapped grip, sold with a brass compass, a treasure map and a leatherette case.
The bottom line A handsome themed object whose optical arithmetic places it well outside astronomy — and it is honest enough about being a set.
A gold-finished collapsible spyglass with a leather grip, a brass compass, a treasure map with deliberate weathering, a case and a cloth. The listing leads with the appearance and the theme, and that is the right order: this is sold as an object, and it should be judged as one.
Thirty divided by twenty-five is 1.2. A 1.2 mm exit pupil is smaller than a daylight pupil, which means the image is dim even in sunshine, and the eye has to sit exactly right to see it at all. That is the arithmetic of a short tube at high magnification.
Because magnification comes from the ratio of two focal lengths, and a long tube gets there without shrinking the exit pupil to nothing. The historical instruments this one imitates were metres long for that reason.
Daylight, at a distance, braced against something. And on a shelf, where the compass and the map do most of the work.
German, French, Italian and Spanish Amazon stores ran from 35 € to 38 € on the day of the survey.
American Amazon store lists it in local currency, which the euro range above sets aside.
British Amazon catalogue holds a record for it that nobody is selling.
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 17 September 2026. The live price is at the top of the page.
| Aperture | 30 mm, as the maker states it |
|---|---|
| Magnification | 25x, as the maker states it |
| Exit pupil | 1.2 mm — 30 divided by 25 |
| True field of view | Not published by the maker. |
| Close focus | Not published by the maker. |
| Prism | BAK4, with a claimed 99 % transmission |
| Coatings | Not published by the maker. |
| Sealing | Not published by the maker. |
| Weight | Not published by the maker. |
| Phone adapter fit | Not published by the maker. |
| Supplied accessories | Spyglass, treasure map, leatherette case, lens cloth, compass, manual; one-year warranty |
| Amazon reference | B0FVRS17HJ (same reference on 6 Amazon marketplaces) |
| EAN | 9313448601700 |
Barely. Thirty millimetres of aperture at twenty-five times gives a 1.2 mm exit pupil, which is dim even in daylight. The Moon will show as a bright disc if the tube can be held still enough.
Because the magnification is high relative to the objective. A 10x50 binocular gives 5 mm; this gives 1.2 mm. The arithmetic is the whole explanation, and it is why classic spyglasses were long rather than powerful.
10–30x zoom · 40 mm objective · 4 mm to 1.3 mm exit pupil
A zoom monocular running from 10x to 30x on a 40 mm objective, with BAK4 prisms, dual focus and a nitrogen-filled aluminium body.
Best for: Daytime viewing where one instrument has to cover several distances
≈ $36 / £28 / €26
12x · 50 mm · 435 g · waterproof and nitrogen-filled
A 12x50 monocular with BaK-4 glass, UR coating, a twist-up eyecup and a nitrogen-filled waterproof body, published at 435 g.
Best for: A pocket instrument for dusk that is meant to be used in poor weather
≈ $130 / £96 / €79
10–30x zoom · 50 mm objective · supplied with phone holder and tripod
A 10–30x zoom monocular on a 50 mm objective, IPX7-sealed and nitrogen-filled, supplied with a phone holder and a metal tripod.
Best for: Daytime and dusk viewing with a phone, where the tripod does the steadying
≈ £31 / €24
