Askar SQA60 Pro Petzval APO Refractor

Askar SQA60 Pro Petzval APO Refractor

Description

The Askar SQA60 Pro is a compact high-performance astrograph developed for wide-field astrophotography applications. Featuring a 60 mm aperture, a 276 mm focal length and a fast focal ratio of f/4.6, it enables bright imaging acquisitions suitable for extended nebulae, large stellar fields and astronomical landscape photography.

The optical system uses an air-spaced six-element Petzval APO design including two SD glass elements. This optical architecture provides excellent chromatic correction together with a fully corrected imaging field without requiring an additional field flattener or corrector.

Compatible with full-frame sensors up to a 44 mm image circle, the SQA60 Pro delivers consistent performance across the entire field. The spot diagram demonstrates an RMS radius below 1 μm at the center and below 2.1 μm in the corners, ensuring sharp and precise stars extending to the edges of the image.

The system also benefits from optimized relative illumination performance. Even at the edges of a full-frame sensor, illumination remains above 95 %, effectively reducing vignetting and improving image uniformity for astrophotography applications.

The compact optical tube measures only 283 mm in length, simplifying transportation and installation on lightweight mounts. Its mechanical construction benefits from precision CNC machining with a refined finish suitable for intensive astrophotography use.

The rear system uses an M48 adapter incorporating an M48×0.75 filter thread and supports a rear connection range between 41 and 66 mm with a recommended distance of 55 mm, ensuring broad compatibility with modern astronomy cameras and imaging accessories.

The Askar SQA60 Pro provides a compact, fast and optimized solution for astrophotographers seeking a high-performance full-frame astrograph with integrated field correction.

Technical specifications

• Aperture : 60 mm
• Focal length : 276 mm
• Focal ratio : f/4.6
• Objective lens : Air-spaced six-element Petzval APO
• 2 SD glass elements
• Format compatibility : Full-frame 44 mm
• Total length : 283 mm

Optical performance :

• Central RMS radius below 1 μm
• Corner RMS radius below 2.1 μm
• More than 95 % illumination on full-frame sensor
• Effective vignetting reduction

Mechanical construction :

• Compact optical tube
• Precision CNC machining
• Optical tube weight : 2.79 kg
• Total weight including rings and dovetail plate : 3.54 kg

Rear connection :

• M48 adapter
• Integrated M48×0.75 filter thread
• Compatible rear connection range from 41 to 66 mm

Recommended distance : 55 mm

Standard package contents :

• SQA60 Pro optical tube
• Oxford fabric carrying bag

Product introduction

Optical Path

The SQA60pro uses a sextuplet air spaced optical design, including 2 SD glass elements.

Spot Diagram

The imaging quality of the optical system can be evaluated by analyzing the distribution of the spots on the spot diagram.

The SQA60pro features a central star point with an RMS radius of less than 1 μm, while the star point in the corners remains below 2.1 μm, delivering fine and precise stars.

Relative Illumination

Relative illumination (RI) represents the combined effect of light loss and attenuation at the corners of the lens. The RI curve illustrates the variation in illumination (%) across the entire imaging area of the sensor.

Illumination variations can negatively affect image quality. The vertical axis represents different percentages of illumination intensity, while the horizontal axis represents the distance from the center of the image to the edge of the sensor.

Even at the extreme edges of a full frame sensor, the SQA60 Pro maintains illumination above 95%, effectively minimizing vignetting.

Specifications

• Aperture : 60 mm
• Focal length : 276 mm
• Focal ratio : f/4.6
• Objective lens : Sextuplet Petzval APO (including 2 SD glass elements)
• Total length : 283 mm
• Format compatibility : Full frame (44 mm)
• OTA weight : 2.79 kg
• Gross weight (including tube rings and dovetail plate) : 3.54 kg
• Rear-end thread type : M48 adapter (with M48×0.75 filter thread)
• Rear-end connection distance : Supports 41 to 66 mm range (recommended connection length : 55 mm)
• Standard package items : SQA60pro OTA and Oxford cloth carrying case

 
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