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 7 timesTracking since Aug 2026

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Where to buy

StarizonaBest price$1,999→

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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 →

Where else it shines

Within reach

Orion Nebula

Colorful nebula captured with live stacking — wings and filaments

Open view →

Rewards a dark sky

Andromeda Galaxy

Long-exposure capture revealing galaxy core and outer structure

Open view →

Easy first target

The Pleiades

Field rich with stars — long exposure pulls in fainter members

Open view →

Also excellent on

Saturn

Processed planetary capture with rings or bands clearly visible

Open view →

✦

There is no eyepiece experience here. Its reward shows up on a sensor, after the exposure — not in the moment.

01What it's good at

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

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

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.

02The Polaris Score

How it scores, and why.

87/ 100

Askar FRA500 Quintuplet Astrograph

#2 of 7 wide-field imaging refractor

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