Skip to content
ApertureFind my telescope
Aperture

Français

Buy the right telescope, not the biggest one

Two models, the numbers decide

Sky-Watcher Skyliner 250PX or GSO Dobson 300/1500?

Sky-Watcher Skyliner 250PX — 254 mm, €693. GSO Dobson 300/1500 — 300 mm, €899. The same method as everywhere on this site: the numbers first, the verdict from them.

Same family (250–300 mm Dobsonian): what changes between these two is aperture, bulk and price — not character.

250–300 mm Dobsonian

Sky-Watcher Skyliner 250PX

Sky-Watcher Skyliner 250PX

240×
Saturn at 240× in 254 mm — exit pupil 1.1 mm, Bortle 6 sky. Computed, not photographed.

€693seen 23 Oct 2026 at Astroshop

See it at AstroshopAll the sellers

250–300 mm Dobsonian

GSO Dobson 300/1500

GSO Dobson 300/1500

300×
Saturn at 300× in 300 mm — exit pupil 1.0 mm, Bortle 6 sky. Computed, not photographed.

€899seen 23 Oct 2026 at Astroshop

See it at AstroshopAll the sellers

Side by side

The GSO Dobson 300/1500 collects 1.4× more light — that is what aperture buys.

Sky-Watcher Skyliner 250PXGSO Dobson 300/1500
Aperture254 mm300 mm
Focal ratio1200 mm · f/4.71500 mm · f/5.0
Typical weight32 kg33 kg
Setup time15 minutes15 minutes
Learning curve3 out of 53 out of 5
Useful magnification≤ 508×≤ 600×
Resolution (Dawes)0.5″0.4″
Observed price€693seen 23 Oct 2026 at Astroshop€899seen 23 Oct 2026 at Astroshop
Where to buySee it at Astroshop See it at Astroshop

Choose the Sky-Watcher Skyliner 250PX if…

  • budget decides: €206 less
  • it has to be carried: 1 kg lighter

Full page on the Skyliner 250PX →

Where to buy

Also search at First Light Optics · Optique Unterlinden · Pierro Astro · Teleskop-Express (searches; neither price nor stock checked)

1 of these 5 links earn us a commission, marked above. Sorted by price, never by what pays. How this site is funded.

Price alert

One email when the price we observe for the Sky-Watcher Skyliner 250PX falls at least 5% below the lowest we observed in the previous 30 days. At most one a week.

A confirmation link comes first, and nothing is sent until you follow it. One click unsubscribes and deletes your address. No cookie. Privacy

Choose the GSO Dobson 300/1500 if…

  • you want the most sky: 1.4× the light

Full page on the Dobson 300/1500 →

Where to buy

Also search at First Light Optics · Optique Unterlinden · Pierro Astro · Teleskop-Express (searches; neither price nor stock checked)

1 of these 5 links earn us a commission, marked above. Sorted by price, never by what pays. How this site is funded.

Price alert

One email when the price we observe for the GSO Dobson 300/1500 falls at least 5% below the lowest we observed in the previous 30 days. At most one a week.

A confirmation link comes first, and nothing is sent until you follow it. One click unsubscribes and deletes your address. No cookie. Privacy

The same sky, through both

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.

The Moon

Skyliner 250PX · Detailed
Dobson 300/1500 · Detailed

Saturn

Skyliner 250PX · Detailed
Dobson 300/1500 · Detailed

The Orion Nebula

Skyliner 250PX · Detailed
Dobson 300/1500 · Detailed

The Andromeda Galaxy

Skyliner 250PX · Detailed
Dobson 300/1500 · Detailed
Photo credits

These thumbnails are built from real photographs, scaled and darkened by the same arithmetic as the large view.

  • The Moon: NASA Scientific Visualization Studio / LRO, public domain
  • The Orion Nebula: NASA, ESA, M. Robberto (heic0601a), CC BY 4.0
  • The Andromeda Galaxy: Adam Evans, Wikimedia Commons, CC BY 2.0

Other duels with these models

Read next

Is it the right one for you? Ask the advisor