One model, judged by its numbers
Sky-Watcher Skyliner 250PX
Where galaxies start having structure and planetary nebulae start having colour. Also where an instrument starts needing a plan rather than a decision.
Family · 250–300 mm Dobsonian
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 | 254 mm |
|---|---|
| Focal ratio | 1200 mm · f/4.7 |
| Mount | Full-size Dobsonian rocker box |
| Typical weight | 38 kg |
| Useful magnification | 42× to 508× at 254 mm |
| Resolution (Dawes) | 0.5″ — the tightest double star this aperture can split |
| Faintest star, suburban sky | around magnitude 13.3 |
| Observed price | €950 seen 2026-08-17 |
Made for
Nebulae, clusters and galaxies, by eye · 5 out of 5
The reason people own these. Nothing else at the price shows as much.
The Moon and the planets · 4 out of 5
Superb when the seeing allows, which is less often than the aperture would like.
Not made for
Learn my way around the sky · 2 out of 5
Not the instrument to learn on. The field is narrow and the setup is a commitment.
Taking it with me · 1 out of 5
No.
The family it belongs to: 250–300 mm Dobsonian
What it does well
- Spiral structure in the brighter galaxies, from a dark site
- Enough light that a nebula filter finally has something to work with
- Still the cheapest route to this much aperture by a wide margin
What it costs you
- 40 kg in two or three pieces. It needs a car, a plan and a body that agrees
- A cooling-down period of half an hour or more before it performs
- Under a bright sky, most of this aperture is buying background glow
Worth knowing about this model
The tube alone is 20 kg and awkward rather than heavy. Measure your car boot before ordering.
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€693 seen 2026-08-23ships 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.