Sky-Watcher Flextube 250P Collapsible Dobsonian — image 1
Sky-Watcher

Sky-Watcher Flextube 250P Collapsible Dobsonian

10 inches of aperture in a tube that collapses to two-thirds its length, the Dobsonian that gives you serious light-grasp and still fits in a car.

89/ 100
Polaris Score
#1 of 5 10-inch Dobsonian
See the breakdown ↓
Aperture
254mm
Focal Length
1200mm
Focal Ratio
f/4.7
Mount Type
Dobsonian
Optical Design
Dobsonian
Weight
27.0 kg
From$999

Lowest in 90 daysLowest ever tracked

Price tracked by PolarisObserved 97 timesTracking since Jul 2026

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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 →
01What it's good at

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

254mm gathers roughly 55 percent more light than an 8-inch, the difference between glimpsing a galaxy and seeing its shape
Best at
✓254mm gathers roughly 55 percent more light than an 8-inch, the difference between glimpsing a galaxy and seeing its shape
✓The Flextube truss collapses the tube down for transport, then extends and locks in seconds with repeatable collimation
✓At f/4.7 it delivers bright, wide low-power views that make sweeping the Milky Way a pleasure
✓It keeps the Dobsonian virtues intact: no power, no alignment, point and observe
Trade-offs
!The open truss lets stray light and dust reach the optics, so a light shroud helps in bad locations
!f/4.7 is demanding on eyepieces and shows coma at the edge without a corrector
!It still weighs enough that the base and tube are separate two-part carries
!No tracking means re-centering by hand at high power
02In plain English

What These Numbers Mean

254mm · f/4.7 · 1200mm FL · Dobsonian
Aperture
254 mm (10 inch)
Ten inches collects about 1,300 times the light of your eye. Galaxies show shape and dust lanes, globular clusters resolve into stars, and the brighter planetary nebulae reveal internal structure from a dark site.
Focal length
1200 mm
Enough for 240x on planets with a 5 mm eyepiece, while a 30 mm eyepiece gives a wide 40x sweep. A single telescope that covers both ends of visual observing.
Focal ratio
f/4.7
Fast optics reach wide, low-power fields easily but demand well corrected eyepieces and regular collimation. Budget wide-angle eyepieces will show soft stars at the field edge here.
Optical design
Collapsible truss Newtonian
The tube collapses to roughly half its length for transport, which is the practical difference between a 10 inch that fits in a hatchback and one that does not. Expect to check collimation after each setup and to use a shroud on damp nights.
Weight
27.5 kg total
About 61 lb split between tube and base. Each piece is a manageable single carry, but this is a garden and driveway telescope, not a hiking one.
Mount
Manual Dobsonian base
Simple, steady and instantly ready with no power or alignment. You nudge to track, so at high magnification objects need regular small pushes and long exposures are not possible.
03The Polaris Score

How it scores, and why.

89/100 · #1 of 5 10-inch Dobsonian
89/ 100
Sky-Watcher Flextube 250P Collapsible Dobsonian
#1 of 5 10-inch Dobsonian
Performance
90
Ease of use
80
Portability
60
Upgrade potential
65

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.

04Who it's for

An honest fit check.

Observers who want 10-inch views but need the tube to shrink for the car or closet
Buy it if you
✓Observers who want 10-inch views but need the tube to shrink for the car or closet
✓Deep-sky hunters chasing fainter galaxies and nebulae than an 8-inch reaches
✓People who value aperture and simplicity over automation
Look elsewhere if you
!Anyone who wants the scope to find and track objects for them
!Imagers, since the base does not track for long exposures
!Observers who need the absolute lightest grab-and-go scope
05Build your rig

What to buy next — and where it leads.

9 pieces of gear, ordered by what changes the view most
Recommended upgrades
Pinpoint stars across the whole field★ Top pickApertura 1x Photographic Coma Corrector

Fixes edge coma inherent to this fast f/4.7 mirror

A worthwhile upgradeApertura Laser Collimator

Precise alignment the fast optics reward, quick after each truss extend

See wider, brighter deep-sky viewsGSO SuperView 30mm 2-inch

Bright wide-field views that play to the fast 10-inch tube

Observe better
Tame lunar glareGSO Moon Filter 13pct 1.25-inch

Improves contrast on nebulae and planets with this setup

Make nebulae popSVBony UHC 1.25-inch

Commonly paired with this telescope

Sharper planets & lunar detailCelestron X-Cel LX 7mm

Commonly paired with this telescope

A sharper everyday viewCelestron X-Cel LX 18mm

Commonly paired with this telescope

Show all compatible gear (6) →
Accessories
Double your magnificationTele Vue 2x Barlow 1.25-inch

Doubles magnification for closer planetary detail with this telescope

See wider, brighter deep-sky viewsExplore Scientific 68deg 28mm 2-inch

Commonly paired with this telescope

Lunar & planetary
Excellent
Deep-sky visual
Excellent
Astrophotography
Not its purpose, a visual scope
06The numbers

Full specifications.

6 measured and stated values
Optics
Optical DesignDobsonian
Aperture254mm
Focal Length1200mm
Focal Ratiof/4.7
Mount & drive
Mount TypeDobsonian
Physical
Weight27.0 kg
07Alternatives

For a different goal, start here.

3 alternatives, each mapped to the goal it wins at
Solid tube

Sky-Watcher Classic 10 Dobsonian

Same 10-inch aperture in a one-piece tube if you have room and prefer no truss

→
Loaded package

Apertura AD10 Dobsonian 10" Telescope with Accessories

10-inch Dob bundled with a 2-inch Crayford, finder and eyepieces

→
Go bigger

Apertura AD12 Dobsonian

12 inches for even more reach if transport is not a constraint

→
Also worth comparing
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Orion SkyQuest XT12 Dobsonian
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Orion SkyQuest XT12 Dobsonian
More capability for deeper views
Celestron NexStar 6SE
Celestron
Celestron NexStar 6SE
Smaller and easier to handle