Askar FRA500 Quintuplet Astrograph
Askar
Askar FRA500 is a 90 mm Petzval flat-field astrograph for wide-to-mid-field nebulae and general deep-sky imaging.
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Specifications
Optics
- Optical design
- Petzval flat-field astrograph
- Aperture
- 90 mm
- Focal length
- 500 mm
- Focal ratio
- f/5.6
- Dawes limit
- 1.29"
- Glass / elements
- Quintuplet Petzval design
Specifications
- Focuser
- 3.5"
Imaging
- Image circle
- 55 mm
- Camera format
- Full frame / APS-C / Micro 4/3
- Full-frame coverage
- Yes
- Back focus
- No strict back-focus calculation required
- Corrected field
- Native full-frame and larger-than-full-frame flat field
- Reducer / flattener
- Optional 0.7× reducer: 350 mm at f/3.9
Mechanical
- Weight
- 4.1 kg
Astrophotography Fit
Best for wide-to-mid-field nebulae and general deep-sky imaging when the mount, camera format, and correction hardware are chosen as one system.
Askar FRA500 sits in the telescope slot for wide-to-mid-field nebulae and general deep-sky imaging. The useful headline specs are aperture 90 mm, focal length 500 mm, f/5.6.
Camera coverage: Full frame / APS-C / Micro 4/3. Image circle: 55 mm. Back focus: No strict back-focus calculation required.
Refractors keep the field routine calmer: no regular collimation, predictable cooldown, and a clean path to autofocus and filtered imaging. The tradeoff is aperture and reach.
Weight matters here: 4.1 kg. Leave payload headroom for the camera, guider, focuser, dew control, and cables instead of judging the mount by bare tube weight alone.
Best paired with
- Corrected field flattener or reducer when the design requires one
- Cooled APS-C or smaller astro cameras matched to the image circle
- Autofocus, guide scope or OAG, and a mount with comfortable payload margin
Not recommended for
- Large full-frame sensors unless the corrected field supports them
- Very small travel mounts near their realistic imaging payload limit
- Buyers expecting one telescope to be ideal for every target size
Where To Buy
Some links on this page are affiliate links. Prices and availability are pulled automatically from each retailer and updated daily.
| Retailer | Price | Availability | View Offer |
|---|---|---|---|
| Telescopes.net Telescopes.net | $1,795.00 | In stock Updated 8/5/2026 | View Offer - $1,795.00 |
| Starizona Starizona | $1,999.00 | In stock Updated 8/5/2026 | View Offer - $1,999.00 |
| High Point Scientific High Point Scientific | $1,999.00 | Out of stock Updated 8/5/2026 | View Offer - $1,999.00 |
Price History
Chronological retailer pricing with out-of-stock points shown at reduced opacity.