Askar 71F Flat-Field Refractor — image 1
Askar

Askar 71F Flat-Field Refractor

A 71mm ED doublet with a built-in flat field, sharp corners with no separate flattener, at a price that undercuts the triplets. A smart, simple first imaging refractor.

84/ 100
Polaris Score
#4 of 8 imaging APO refractors
See the breakdown ↓
Aperture
71mm
Focal Length
490mm
Focal Ratio
f/6.9
Mount Type
None (OTA only)
Optical Design
ED Doublet Refractor
Weight
2.3 kg
From$599

Lowest in 90 daysLowest ever tracked

Price tracked by PolarisObserved 76 timesTracking since Jul 2026

Try in simulator →
What it's built forOpen these in the simulator →

This telescope was built for sweeping wide.

A short, fast refractor with a generous true field — the whole sword of Orion in one view, star fields that spill past the field stop. It rewards low power and dark skies far more than chasing magnification.

Widest true fieldsTack-sharp to the edge
The view people remember

Andromeda, wider than the Moon.

A vast soft oval with a blazing core — two and a half million light-years of galaxy, spilling well past the field of view under a genuinely dark sky.

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

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

A flat-field doublet gives corner-sharp stars without buying and spacing a flattener.
Best at
✓A flat-field doublet gives corner-sharp stars without buying and spacing a flattener.
✓ED glass controls most false colour for clean, largely colour-free stars.
✓Light (2.3kg) and compact, ideal on a small tracker for wide-field imaging.
✓Priced below the triplets, so more budget is left for the mount and camera that matter.
Trade-offs
!A doublet leaves a faint colour trace on the very brightest stars versus a triplet.
!OTA only; a tracking mount and camera are extra.
!At f/6.9 it is a touch slower than the fast astrographs, so exposures run longer.
!71mm is a wide-field aperture, not a light bucket for faint small objects.
02In plain English

What These Numbers Mean

71mm · f/6.9 · 490mm FL
Aperture
71 mm
Under three inches of glass. It is enough for wide-field imaging and pleasant low-power views of clusters and the Moon, but faint galaxies and high-magnification planetary work are beyond what this size can deliver.
Focal length
490 mm
A widely useful wide field. Large nebulae like the North America, the Rosette and the Andromeda Galaxy fit an APS-C frame comfortably, which is exactly the target list most people start with.
Focal ratio
f/6.9
Middle speed. Exposures run a little longer than an f/5 astrograph needs, in exchange for gentler tolerances on focus, tilt and eyepiece quality. A sensible ratio for someone still learning the workflow.
Optical design
Flat-field ED refractor
The field flattening is designed in rather than bolted on, so stars stay round to the corners without a separate flattener and its spacing calculations. Fewer parts in the train means fewer things to get wrong.
Weight
2.3 kg tube
About 5 lb. It rides on a star tracker or the smallest equatorial mounts, packs easily, and keeps the total cost of a first imaging setup modest.
Mount
OTA only
No mount included, but very little is required. A tracker with a decent polar alignment will produce round stars at this focal length and weight.
03The Polaris Score

How it scores, and why.

84/100 · #4 of 8 imaging APO refractors
84/ 100
Askar 71F Flat-Field Refractor
#4 of 8 imaging APO refractors
Performance
83
Ease of use
84
Portability
88
Upgrade potential
79

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.

Beginners who want a corrected imaging refractor without the triplet price.
Buy it if you
✓Beginners who want a corrected imaging refractor without the triplet price.
✓Travellers after a small, light wide-field scope.
✓Anyone prioritising mount and camera budget over the optical tube.
Look elsewhere if you
!Imagers chasing the last few percent of star-colour purity, a triplet edges it.
!Small-target shooters who need long focal length.
!Deep-sky visual observers; it is an imaging-first tube.
05Build your rig

What to buy next — and where it leads.

7 pieces of gear, ordered by what changes the view most
Recommended upgrades
No fogging on long sessions★ Top pickPegasus Astro Multi-Channel Dew Controller

Stops dew from ending an imaging night.

Make nebulae popOptolong UHC Filter 2″

Lifts nebula contrast out of light-polluted skies.

Observe all night, no AA batteriesCelestron PowerTank Lithium

Runs the mount (and heaters) all night off one pack.

Growth path
Better tracking & light imagingSky-Watcher HEQ5 Pro SynScan GoTo Mount✓ Compatible

Commonly paired with this telescope

Portable astrophotographyZWO AM5N Harmonic Equatorial Mount✓ Compatible

Start capturing images of the Moon and planets

A versatile upgradeSky-Watcher Star Adventurer GTi GoTo EQ Mount Kit✓ Compatible

Commonly paired with this telescope

Start imagingZWO ASI533MC Pro

Start capturing images of the Moon and planets

Lunar & planetary
Excellent contrast
Deep-sky imaging
Strong with a flattener
Deep-sky visual
Wide, low-power views
06The numbers

Full specifications.

6 measured and stated values
Optics
Optical DesignED Doublet Refractor
Aperture71mm
Focal Length490mm
Focal Ratiof/6.9
Mount & drive
Mount TypeNone (OTA only)
Physical
Weight2.3 kg
07Alternatives

For a different goal, start here.

2 alternatives, each mapped to the goal it wins at
faster/flatter

Askar FRA400C Quintuplet APO Refractor

A five-element astrograph from the same maker, faster and more corrected, for more.

→
more aperture

Sky-Watcher Evostar 80ED

A slightly larger doublet, though it needs a separate flattener for flat fields.

→
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SVBony SV555 54mm f/4.5 APO
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