Sky-Watcher

Sky-Watcher Flextube 250P SynScan GoTo Collapsible Dobsonian

Ten inches of light-grasp that finds and tracks for you, in a truss tube that still drops into a hatchback, the sweet-spot GoTo Dob for most deep-sky observers.

85/ 100

Polaris Score

#1 of 1 10" GoTo Dobsonian

See the breakdown ↓

Aperture

254mm

Focal Length

1200mm

Focal Ratio

f/4.7

Mount Type

Dobsonian (GoTo)

Optical Design

Dobsonian

Weight

36 kg

From$1,895

Lowest in 90 days

Price tracked by PolarisObserved 8 timesTracking since Aug 2026

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Where to buy

Agena AstroProductsPartnerBest price$1,895→Astronomics$1,895→Starizona$1,895→High Point Scientific$1,895→

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What it's built forOpen these in the simulator →

This telescope was built to gather light.

254 mm of aperture pulls in the faint light that galaxies and clusters live or die on. Point it up under a dark sky and objects that are rumors in smaller scopes resolve into real structure.

Sweet spot 190–320×Rewards dark skies

The view people remember

The Sombrero, brim and all.

A bright edge-on galaxy crossed by a sharp dark dust lane — the brim of the hat — one of the most distinctive shapes in the entire deep sky.

See The Sombrero Galaxy through this telescope →

Where else it shines

Rewards a dark sky

Andromeda Galaxy

Galaxy structure starts revealing — bright core, extended halo

Open view →

Easy first target

The Pleiades

Densely packed showpiece — hundreds of stars across multiple magnitudes

Open view →

Within reach

Orion Nebula

Stronger structure — embedded stars plus dark lanes within the core

Open view →

Also excellent on

Saturn

Sharp planetary detail — multiple bands, festoons, and surface variation

Open view →

✦

It is a light bucket, not a travel scope — the reach comes with real bulk and a dark-sky drive out of town.

01What it's good at

What it's best at — and the trade-offs.

Best at

✓254mm gathers ~55% more light than an 8-inch, enough to turn faint galaxy smudges into shapes with structure

✓SynScan GoTo motorizes both axes: align on a few stars and it slews to and tracks any of 42,000+ objects, so a big Dob stops being a hunt and starts being a tour

✓The Flextube truss collapses the tube for transport, then extends and holds collimation, the only way a scope this size fits in a normal car

✓It keeps the Dobsonian payoff intact: aperture-per-dollar nothing else touches, on a stable, intuitive alt-az base

Trade-offs

!It's heavy and bulky: plan on a two-part carry and, at the larger sizes, help or a wheeled setup

!The GoTo base needs stable power (a battery pack or supply) that a manual Dob does not

!The open truss lets stray light and dust reach the mirror, so a shroud helps at real sites

!At f/4.7 it's demanding on eyepieces and shows edge coma without a corrector; alt-az tracking suits visual use, not imaging

02In plain English

What These Numbers Mean

Aperture

254 mm (10 inch)

Ten inches gathers roughly 1,300 times the light of your eye, which is enough to make faint galaxies genuinely rewarding rather than merely detectable. With GoTo attached, working through a list of a dozen of them in a night becomes realistic.

Focal length

1200 mm

Reaches 240x with a 5 mm eyepiece for planetary work and 40x with a 30 mm for wide sweeps. Long enough for detail, short enough to stay versatile.

Focal ratio

f/4.7

Fast, so wide, low-power fields come easily, but eyepiece quality and collimation both matter. A coma corrector is a real improvement rather than a refinement at this ratio.

Optical design

Collapsible truss Newtonian

The truss collapses for transport, halving the storage length of a 10 inch tube. The trade is a collimation check after every setup and a shroud to keep stray light and dew off the mirror.

Weight

36 kg total

About 79 lb once the motorised base is included, which is significantly heavier than the manual version. Two carries minimum, and the base alone is a solid lift.

Mount

SynScan GoTo Dobsonian base

Motors on both axes plus a 42,000 object database mean it slews to targets and tracks them, so faint objects stay centred while you study them. Alt-azimuth tracking is excellent visually but does not support long-exposure imaging.

02The Polaris Score

How it scores, and why.

85/ 100

Sky-Watcher Flextube 250P SynScan GoTo Collapsible Dobsonian

#1 of 1 10" GoTo Dobsonian

Performance

Ease of use

Portability

Upgrade potential

Polaris weighs optical capability, how easy the scope is to live with, how portable it is, and how far it takes you before you outgrow it — not list price or brand.

03Who it's for

An honest fit check.

Buy it if you

✓Deep-sky observers who want 10" of light-grasp and let the mount find and track objects for them

✓Anyone chasing faint galaxies, globulars, and planetary nebulae that smaller scopes only hint at

✓Observers with the space and a way to move a large two-part scope who want maximum aperture without a permanent pier

Look elsewhere if you

!Anyone who needs a light, one-hand grab-and-go setup, this is a deliberate haul

!Deep-sky imagers, since an alt-az Dob base can't do long exposures

!Observers short on storage or without a way to transport a bulky base and tube

04Build your rig

What to buy next — and where it leads.

Recommended upgrades

See wider, brighter deep-sky views★ Top pickExplore Scientific 68deg 28mm 2-inch

Commonly paired with Sky-Watcher Flextube 250P SynScan GoTo Collapsible Dobsonian

$169View details →

Pinpoint stars across the whole fieldApertura 1x Photographic Coma Corrector

Sharpens stars to the very edge of the field at fast focal ratios

$269.95View details →

Make nebulae popOptolong UHC Filter 2″

Improves contrast on nebulae and planets with this setup

$85View details →

Observe better

Tame lunar glareGSO Moon Filter 13pct 1.25-inch

Improves contrast on nebulae and planets with this setup

$11.95View details →

Make nebulae popSVBony UHC 1.25-inch

Commonly paired with this telescope

View details →

Sharper planets & lunar detailCelestron X-Cel LX 7mm

Commonly paired with this telescope

$109.95View details →

A sharper everyday viewCelestron X-Cel LX 18mm

Commonly paired with this telescope

$109.95View details →

Show all compatible gear (5) →

Accessories

Double your magnificationTele Vue 2x Barlow 1.25-inch

Doubles magnification for closer planetary detail with this telescope

$153View details →

Lunar & planetary

Excellent

Deep-sky visual

Excellent

Astrophotography

Not its purpose, a visual scope

05The numbers

Full specifications.

Optics

Optical DesignDobsonian

Aperture254mm

Focal Length1200mm

Focal Ratiof/4.7

Mount & drive

Mount TypeDobsonian (GoTo)

Physical

Weight36 kg

06Alternatives

For a different goal, start here.

Smaller & lighter

Sky-Watcher Flextube 200P SynScan GoTo Collapsible Dobsonian

The 8-inch GoTo version if you want an easier one-person carry for less money

→More aperture

Sky-Watcher Flextube 300P SynScan GoTo Collapsible Dobsonian

The 12-inch reaches noticeably deeper if you can handle the extra bulk and weight

→Manual & cheaper

Sky-Watcher Flextube 250P Collapsible Dobsonian

The same 10-inch aperture without motors if you'd rather star-hop and save

→

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Celestron RASA 8 Rowe-Ackermann Schmidt Astrograph

Smaller and easier to handle