One model, judged by its numbers
Sky-Watcher Evostar 90/900 AZ-3
The shape most people picture when they picture a telescope. Sealed tube, nothing to collimate, and a standing eyepiece height that suits sharing.
What it shows, really
These circles are simulations, computed from the aperture, the magnification and the sky — indicative, not exact. A real night also depends on the turbulence, your eyes and your experience. Closer to the truth than the photo on the box; still not a promise.
Under a suburban sky (Bortle 6), through a common 25 mm eyepiece for wide targets and a 10 mm for planets. Every circle is the true field — nothing is enlarged.
The numbers
| Aperture | 90 mm |
|---|---|
| Focal ratio | 900 mm · f/10.0 |
| Mount | AZ-3 alt-az with slow-motion controls on both axes, aluminium tripod |
| Typical weight | 11.7 kg |
| Eyepieces | 25 mm and 10 mm |
| Useful magnification | 15× to 180× at 90 mm |
| Resolution (Dawes) | 1.3″ — the tightest double star this aperture can split |
| Faintest star, suburban sky | around magnitude 11.0 |
| Observed price | €258 seen 2026-08-30 |
Should you buy it?
- Yes if what you mainly want is sharing it with children: that is what this family does best.
- No if your priority is nebulae, clusters and galaxies, by eye: other families do better for the same money.
Computed from its family's per-goal scores and its own numbers — not a rating, not one evening's opinion.
Made for
Sharing it with children · 4 out of 5
Standing height, sealed tube, and no mirror to knock out of line.
Not made for
Nebulae, clusters and galaxies, by eye · 2 out of 5
Bright clusters and the Orion Nebula. Galaxies are mostly out of reach.
The family it belongs to: 70–90 mm refractor on an alt-az mount
What it does well
- Point it and look. No collimation, ever
- The eyepiece stays at a comfortable height wherever you aim
- Doubles as a daytime spotting scope
What it costs you
- 70–90 mm is not much light. Deep sky is a short list
- Cheap achromats show a violet fringe on the Moon and bright planets
- The bundled tripod is usually the weak part — a wobbly tripod ruins a good tube
Worth knowing about this model
The long achromat the French forums name when a refractor is the right answer: f/10 keeps the colour fringing small, the AZ-3 has real slow-motion knobs, and nothing needs adjusting, ever. A 90 cm tube on a tripod — fine on a balcony where a Dobsonian will not fit. Less light than a 130 mm tabletop at a similar price; that is the trade, not a flaw.
Prices are observed on the date shown, never live. Links marked paid link earn us a commission and cost you nothing extra.
Where to buy
- Astroshoppaid link€258 seen 2026-08-30ships DE, FR, EU
- Amazon.frships FR
- First Light Opticsships GB
- Optique Unterlindenships FR
- Pierro Astroships FR
- Teleskop-Expressships DE, EU
1 of these 6 links earn us a commission, marked above. Sorted by price, never by what pays. How this site is funded.