Askar SQA55 55mm f/4.8 Petzval Astrograph

The Askar SQA55 is a compact, high-performance Petzval astrograph designed for astrophotography and high-quality daytime imaging. Featuring a quintuplet air-spaced optical system with SD and ED glass elements, it delivers a flat, well-corrected image field without the need for an additional field flattener.

Optical Design and Image Quality

The SQA55 employs a quintuplet Petzval APO design incorporating one SD glass element and one ED glass element. This optical configuration provides excellent colour correction, high contrast, and sharp star profiles across the image field.

On-axis star PSF performance reaches approximately 2.5 μm, with corner performance around 4 μm, ensuring pinpoint stars and consistent resolution from centre to edge. The telescope supports a 44mm image circle, making it suitable for full-frame camera sensors.

No Back Focus Calculation Required

Thanks to the Petzval optical structure, back focus spacing is simplified. Optimal performance is achieved by positioning the camera sensor between 50–60mm from the rear M48×0.75 connection thread, with 55mm recommended.

Compact and Practical Mechanical Design

The SQA55 features a removable and reversible lens hood, allowing the telescope to be stored in a more compact form when not in use. This makes it well suited to portable imaging setups and travel.

With an OTA weight of just 1.84kg (2.18kg including handle and dovetail), the SQA55 is easy to mount on a wide range of equatorial tracking mounts.

Astrophotography and Daytime Imaging

While optimised for astrophotography, the Askar SQA55 also performs well for daytime landscape and telephoto imaging. The fast f/4.8 focal ratio allows efficient light capture, making it suitable for both night-sky and terrestrial photography.

Product Images

Specifications

Diagrams and Reference Images

Astrophotography Examples

NGC 7000 – Askar SQA55 with ZWO ASI6200

M20 & M8 – Askar SQA55 with ZWO ASI2600MC Pro

NGC 6888 – Askar SQA55 with ZWO ASI2600MC