Askar SQA55 Quintuplet Petzval Astrograph 55mm f/4.8

Askar SQA55 Quintuplet Petzval Astrograph — 55mm f/4.8

The Askar SQA55 is a 55mm aperture, 264mm focal length, f/4.8 quintuplet air-spaced Petzval astrograph designed for astrophotographers who demand sharp, flat full-frame star fields with the speed and portability to image anywhere. The optical design incorporates one piece of SD glass and one piece of ED glass to suppress chromatic aberration across the entire 44mm image circle, producing clean round stars from centre to corner on full-frame and APS-C sensors.

As a Petzval-design telescope, the SQA55 does not require a separate flattener — the five-element optical group delivers a flat field natively. A manual focus ring with an adjustable dew shield allows precise focus control in the field, and the 14-blade aperture diaphragm provides smooth out-of-focus backgrounds when the aperture is stopped down for daytime or landscape photography.

The SQA55 ships with a military-grade waterproof carrying case — one of the only astrographs in this aperture class to do so — making it a genuinely travel-ready system for remote dark-sky sites, star parties, and expeditions.

Who Is This Product Best For?

• Travel and portable-mount astrophotographers who need a full-frame-capable astrograph in the smallest, lightest, most rugged package available.
• Intermediate to advanced astrophotographers who want a fast, high-quality Petzval design without adding a flattener to their imaging train.
• Wide-field deep-sky imagers targeting large nebulae, star clusters, and Milky Way fields that benefit from 264mm focal length and f/4.8 speed.
• Dual-use photographers who also want a high-quality telephoto lens for landscape and daytime photography.
• Imagers in light-polluted skies where the f/4.8 speed dramatically shortens required exposure times.

Why Choose the Askar SQA55?

• Quintuplet Petzval with SD + ED glass — flat-field, colour-corrected performance across the full 44mm image circle at f/4.8 with no external flattener required.
• Fast f/4.8 focal ratio — collects light significantly faster than f/6 or f/7 instruments, cutting exposure times for faint nebulae and galaxies.
• Military-grade waterproof case included — the only astrograph in this class that ships with expedition-grade protection.
• 14-blade aperture iris — adjustable from f/4.8 to f/22 for daytime photography with smooth, rounded bokeh.
• Dual-purpose design — usable as a high-quality telephoto lens for landscape, wildlife, and event photography.
• Full-frame 44mm image circle — covers all modern full-frame DSLR, mirrorless, and dedicated astronomy cameras.
• Compact and lightweight at 1.84kg OTA — compatible with ultralight tracking mounts for travel imaging.
• Quick-release accessory system — four quick-release bases on the tube body accept the optional quick-release handle bar and accessories tool-free.

Recommended Uses

• Wide-field deep-sky astrophotography (nebulae, star clusters, Milky Way)
• Narrowband and broadband filter imaging from light-polluted sites
• Travel and remote dark-sky imaging on ultralight mounts
• Full-frame DSLR, mirrorless, and dedicated astronomy camera imaging
• Landscape and telephoto photography (daytime use with aperture iris)
• Portable guided and unguided wide-field imaging

Compatibility and Accessory Notes

Camera connection: M48×0.75 rear thread with built-in M48×0.75 2" filter thread. Compatible with standard T-rings and M48 camera adapters. The recommended back focus connection distance is 55mm (range: 50–60mm). DSLR and mirrorless cameras connect via a T-ring; dedicated astronomy cameras with M48 nosepieces connect directly.

Filter compatibility: M67 front thread (67mm screw-in filters); M48×0.75 rear thread accepts 2" astronomy filters directly.

Optional accessories: SQA55 Quick-Release Handle Bar, SQA55 AF Kit (electronic focuser adapter, sold separately).

Not compatible with the SQA Series Handle Bar or SQA Series Heightening Section — those accessories require a different mounting interface and are designed for the SQA70 and larger models.

Important Limitations

• Manual focus only — the SQA55 does not have a motorized focuser. An electronic focuser requires the optional SQA55 AF Kit.
• Not for visual observing — the SQA55 has no eyepiece holder or visual adapter. It is a dedicated photographic instrument.
• 55mm back focus must be respected — the specified 50–60mm back focus range is critical for field flatness. Spacers outside this range will degrade corner star quality.
• Closest focus distance 5m — the SQA55 cannot focus on subjects closer than 5 metres, limiting its terrestrial photography applications.
• No dovetail plate included — the SQA55 ships with the OTA, handle, and carrying case only. A dovetail plate or tube rings are required for mounting on a standard saddle.

Frequently Asked Questions

Do I need a flattener?
No. The quintuplet Petzval design provides a flat field natively across the full 44mm image circle at f/4.8.

Can I use it for visual observing?
No. The SQA55 is a dedicated imaging instrument with no eyepiece holder.

What is the back focus?
55mm recommended, with a usable range of 50–60mm from the base of the M48×0.75 male thread.

Is a motorized focuser available?
Yes — the optional SQA55 AF Kit adapts virtually any brand of electronic focuser motor to the SQA55's focus ring, sold separately.

Does it work as a camera lens?
Yes, with the aperture iris set between f/4.8 and f/22. The closest focus distance is 5m, so it is best suited for landscape, astroscape, and distant subjects rather than close-up photography.

What mount do I need?
At 2.18kg gross, any equatorial tracking mount with at least a 4–6kg payload rating works well for imaging, including ultralight mounts like the ZWO AM5, iOptron HEM27, or Sky-Watcher Star Adventurer GTi.

Our Recommendation

At Ontario Telescope and Accessories, we recommend the Askar SQA55 for any astrophotographer who values portability without optical compromise. The f/4.8 speed, flat-field Petzval design, and military-grade carrying case make it one of the most capable travel astrographs available at any price point. If you regularly image from remote locations, dark-sky parks, or travel internationally for astrophotography, the SQA55 delivers professional-grade results from a system that fits in carry-on luggage. For larger aperture or longer focal length, consider the SQA70 or SQA85.

Optical Diagram Reports

The following diagrams are provided for customers who wish to review the mechanical dimensions, camera connection specifications, and electronic focuser assembly details for the Askar SQA55.