Askar SQA85

​The Askar SQA85 is a high-quality 85mm f/4.8 quintuplet Petzval astrograph designed to meet the rigorous demands of astrophotographers seeking exceptional clarity and precision. Its innovative optical system features a five-element air-spaced lens design, incorporating two pieces of Super ED (SD) glass. This configuration ensures superior chromatic correction and sharp star performance across the entire field of view. Notably, the central star point boasts an RMS radius of less than 1.6 microns, while the corner star points maintain an impressive RMS radius under 2.5 microns, resulting in exceptionally fine star images. Furthermore, the integrated Petzval design provides a flat field without the need for additional flatteners, supporting a full-frame 44mm image circle. This eliminates the complexity of calculating back focus, allowing users to connect their imaging equipment directly within a 40mm to 70mm range for immediate use.

Complementing its optical excellence, the SQA85 is equipped with a robust 2.8-inch dual-speed rack-and-pinion focuser, compatible with most motorized focusers on the market. The focuser offers 32mm of travel and features high-precision engraved scales, facilitating meticulous focusing adjustments. A 360° rotator with a precision scale at the rear enables effortless framing adjustments, while the retractable dew shield protects the lens from stray light and dew formation. The telescope's integrated tube ring showcases a hollow design to reduce weight and includes multiple M4 and M6 threaded holes for versatile accessory attachment. Additionally, the handle atop the tube ring is slotted with a multifunctional finder base, and the standard Vixen-style 290mm dovetail plate ensures compatibility with a wide range of mounts. These thoughtfully designed features make the Askar SQA85 a versatile and user-friendly instrument, ideal for capturing the intricate beauty of the cosmos.

 

The  Locking Screw Position Diagram

SQA85 Electronic Focuser Assembly Diagram

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