Askar FRA500 Quintuplet Astrograph — image 1
Sharpstar / Askar

Askar FRA500 Quintuplet Astrograph

A 90mm f/5.6 flat-field quintuplet astrograph, built from the sensor backward to deliver pinpoint stars across a full-frame field with no separate flattener to buy or tune.

87/ 100
Polaris Score
#2 of 7 wide-field imaging refractor
See the breakdown ↓
Aperture
90mm
Focal Length
500mm
Focal Ratio
f/5.6
Mount Type
None (OTA only)
Optical Design
Quintuplet Astrograph
Weight
3.9 kg
From$1,999

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Price tracked by PolarisObserved 55 timesTracking since Aug 2026

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Where to buy

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What it's built forOpen these in the simulator →

This telescope was built for the camera.

A fast f/5.6 astrograph designed to throw a wide, flat, well-corrected field onto a sensor. It is an optical tube first — give it a tracking mount and a camera and it rewards long exposures, not eyepieces.

f/5.6 — built to imageNeeds a tracking mount
The view people remember

The Whirlpool, and its companion.

A face-on spiral with a smaller galaxy caught at the end of one arm — on a dark night the spiral structure lifts off the sky in a way photographs almost prepare you for.

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

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

The five-element Petzval design bakes the field flattener into the tube, so stars stay round to the corners of a full-frame sensor out of the box
Best at
✓The five-element Petzval design bakes the field flattener into the tube, so stars stay round to the corners of a full-frame sensor out of the box
✓500mm at f/5.6 frames the larger nebulae and galaxies beautifully while collecting light fast enough for reasonable exposures
✓A locking helical or rack focuser and a rotator make framing and back-focus repeatable session to session
✓At under 4kg it rides comfortably on lightweight star trackers and small equatorial mounts
Trade-offs
!It is a dedicated astrograph, so visual use is possible but not the point
!500mm is short, so small targets stay small in the frame
!As an OTA it needs a tracking mount, camera and guiding to produce results
!The corrector optics can dew and benefit from a heater on damp nights
02In plain English

What These Numbers Mean

90mm · f/5.6 · 500mm FL
Aperture
90 mm
Three and a half inches of glass gathers about 56 percent more light than a 72 mm astrograph, which is the difference between a faint nebula appearing after four hours and appearing after two and a half.
Focal length
500 mm
Wide but not extreme. It frames the larger nebulae on APS-C while still giving usable scale on brighter galaxies, making it a genuine one-telescope choice for deep-sky imaging.
Focal ratio
f/5.6
Fast optics with a real aperture behind them. Exposures build quickly, guiding tolerances remain generous, and the combination works well under moderately light-polluted skies with a dual-band filter.
Optical design
Quintuplet Petzval astrograph
Five elements with the flattener integrated, so corner stars stay round across full frame and there is no spacing to compute. The design is also well corrected visually, so it doubles as a pleasant wide-field eyepiece scope.
Weight
3.9 kg tube
Around 9 lb, still within reach of compact strain-wave mounts and easy to carry to a dark site fully assembled in a case.
Mount
OTA only
You supply the mount. At 500 mm with a guide scope, a small tracking equatorial with autoguiding gets you round stars without a heavy investment.
03The Polaris Score

How it scores, and why.

87/100 · #2 of 7 wide-field imaging refractor
87/ 100
Askar FRA500 Quintuplet Astrograph
#2 of 7 wide-field imaging refractor
Performance
90
Ease of use
70
Portability
85
Upgrade potential
80

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.

Astrophotographers who want a grab-and-shoot wide-field apo with corners already handled
Buy it if you
✓Astrophotographers who want a grab-and-shoot wide-field apo with corners already handled
✓Imagers on trackers or small EQ mounts where weight matters
✓People framing larger deep-sky objects that a longer scope would crop
Look elsewhere if you
!Visual observers, since this is an imaging tube first with a narrow visual use case
!Anyone chasing small galaxies or planets that need long focal length
!Buyers who need a complete scope, since it is an OTA that requires a tracking mount and camera
05Build your rig

What to buy next — and where it leads.

7 pieces of gear, ordered by what changes the view most
Recommended upgrades
Make nebulae pop★ Top pickOptolong OIII Filter 2″

Isolates emission nebulae for high-contrast wide-field imaging under light pollution

No fogging on long sessionsPegasus Astro Multi-Channel Dew Controller

Keeps the front optics dew-free across a full imaging night

Observe all night, no AA batteriesCelestron PowerTank Lithium

Runs the mount, camera and dew heater away from mains power

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 ASI2600MC Pro

Start capturing images of the Moon and planets

Wide-field deep-sky imaging
Excellent, flat field
Lunar & planetary
Small image scale
Visual use
Possible, but an imaging tube
06The numbers

Full specifications.

6 measured and stated values
Optics
Optical DesignQuintuplet Astrograph
Aperture90mm
Focal Length500mm
Focal Ratiof/5.6
Mount & drive
Mount TypeNone (OTA only)
Physical
Weight3.9 kg
07Alternatives

For a different goal, start here.

3 alternatives, each mapped to the goal it wins at
Wider field

Askar 65PHQ Quintuplet Astrograph

A shorter 65mm quintuplet if you want to frame even larger regions of sky

→
Faster and shorter

Askar FRA400C Quintuplet APO Refractor

A 72mm f/5.6 sibling at 400mm for the widest fields and fastest exposures

→
Budget alternative

William Optics ZenithStar 81 APO Doublet

An 81mm doublet plus flattener if you want to spend less and do not mind matching optics

→
Also worth comparing
Askar 80PHQ Quadruplet Astrograph
Sharpstar / Askar
Askar 80PHQ Quadruplet Astrograph
Closest alternative at this size
Celestron C9.25 Schmidt-Cassegrain OTA
Celestron
Celestron C9.25 Schmidt-Cassegrain OTA
More capability for deeper views
William Optics RedCat 71 APO
William Optics
William Optics RedCat 71 APO
Smaller and easier to handle