Sky-Watcher Skymax 180 mm Maksutov-Cassegrain Telescope OTA — image 1
Sky-Watcher

Sky-Watcher Skymax 180 mm Maksutov-Cassegrain Telescope OTA

A 7-inch Maksutov that is a planetary and lunar specialist above all else: a long, sealed tube whose high-contrast optics reward patient observers chasing fine detail on the planets, Moon and double stars.

86/ 100
Polaris Score
#1 of 4 large Maksutov OTA
See the breakdown ↓
Aperture
180mm
Focal Length
2700mm
Focal Ratio
f/15
Mount Type
None (OTA only)
Optical Design
Maksutov-Cassegrain
Weight
8.5 kg
From$1,675

$276 above 90-day lowLast $1,399 in Jul 2026

Price tracked by PolarisObserved 97 timesTracking since Jul 2026

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What it's built forOpen these in the simulator →

This telescope lives for the planets.

An f/15 focal length built to magnify. Where fast scopes sweep wide, this one holds a single planet rock-steady at high power — a telescope for the patient observer on a steady night.

Sweet spot 140–230×Loves steady seeing
The view people remember

Saturn, with its rings tilted wide.

The one you call people outside to see — the rings standing clear of the planet, the Cassini Division a clean black line drawn around them.

See Saturn through this telescope →
01What it's good at

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

180mm of aperture at f/15 delivers exceptional planetary contrast, the kind of view that resolves cloud belts and the Cassini division cleanly
Best at
✓180mm of aperture at f/15 delivers exceptional planetary contrast, the kind of view that resolves cloud belts and the Cassini division cleanly
✓The sealed Maksutov design has no exposed mirror and never needs collimation, so it holds its sharpness with minimal care
✓As a bare OTA it drops onto any capable mount you own or plan to buy, giving full control of the setup
✓The long 2700mm focal length reaches very high magnification while staying easy on eyepiece quality
Trade-offs
!It is an OTA only, so budget for a substantial mount or it does nothing
!The long tube has a large moment arm and needs a genuinely stable mount
!The closed tube takes a long time to reach thermal equilibrium on cold nights
!f/15 is far too slow for deep-sky imaging
02In plain English

What These Numbers Mean

180mm · f/15 · 2700mm FL
Aperture
180 mm (7 inch)
Seven inches of aperture in a Maksutov is unusual and expensive to make. It gathers about 660 times the light of your eye and has the resolving power to split very close double stars and show fine festoons and belt detail on Jupiter.
Focal length
2700 mm
Very long. It reaches 270x with a 10 mm eyepiece and can be pushed further when the seeing allows. The field is inherently narrow, so this is a high-magnification instrument rather than a general-purpose one.
Focal ratio
f/15
Extremely slow, which is what produces the contrast and the flat, aberration-free images planetary observers value. Deep-sky work is limited to bright compact objects, and imaging deep sky is impractical.
Optical design
Maksutov-Cassegrain
A sealed design with a small central obstruction that comes closer to refractor-like contrast than any other catadioptric. It never needs collimation, but the large corrector is heavy and slow to cool.
Weight
8.5 kg tube
About 19 lb in a compact tube. It needs a solid mount to hold steady at 300x, and the mass is concentrated, so balance and a firm tripod matter more than the number suggests.
Cooldown
2 hours or more
This is the longest cooldown in the Maksutov range, because of the thick corrector and the sealed tube. Serious planetary observers put a 180 Mak outside at sunset and start observing well after dark.
03The Polaris Score

How it scores, and why.

86/100 · #1 of 4 large Maksutov OTA
86/ 100
Sky-Watcher Skymax 180 mm Maksutov-Cassegrain Telescope OTA
#1 of 4 large Maksutov OTA
Performance
92
Ease of use
60
Portability
45
Upgrade potential
75

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.

Planetary, lunar and double-star observers who want maximum detail
Buy it if you
✓Planetary, lunar and double-star observers who want maximum detail
✓People who already own a sturdy mount and just need the optics
✓Observers who value a low-maintenance sealed tube
Look elsewhere if you
!Wide-field or deep-sky fans, since f/15 gives a very narrow field
!Anyone without a heavy mount rated to carry the long tube steadily
!Beginners who need a complete, ready-to-use package
05Build your rig

What to buy next — and where it leads.

7 pieces of gear, ordered by what changes the view most
Recommended upgrades
Sharper planets & lunar detail★ Top pickCelestron X-Cel LX 9mm

A sharp mid-to-high-power eyepiece that suits this long planetary tube

Observe all night, no AA batteriesTele Vue 2.5x Powermate

Clean high-power reach for the finest planetary detail

No fogging on long sessionsPegasus Astro Multi-Channel Dew Controller

Keeps the corrector plate clear on humid nights

Imaging path
Better tracking & light imagingCelestron Advanced VX (AVX) Equatorial Mount✓ Compatible

Commonly paired with this telescope

Portable astrophotographyZWO AM5N Harmonic Equatorial Mount✓ Compatible

Start capturing images of the Moon and planets

Permanent-setup astrophotographySky-Watcher EQ6-R Pro✓ Compatible

Commonly paired with this telescope

Start imagingZWO ASI662MC

Start capturing images of the Moon and planets

Lunar & planetary
Excellent
Deep-sky visual
Good
Astrophotography
Lunar and planetary only
06The numbers

Full specifications.

6 measured and stated values
Optics
Optical DesignMaksutov-Cassegrain
Aperture180mm
Focal Length2700mm
Focal Ratiof/15
Mount & drive
Mount TypeNone (OTA only)
Physical
Weight8.5 kg