SQA85 Astrograph

The SQA85 is an astrograph featuring an 85mm aperture, 408mm focal length, and a native focal ratio of f/4.8. Its optical system employs a five-element fully separated design incorporating two SD (Extra-low Dispersion) glass elements, delivering exceptional star rendering with outstanding full-field illumination and MTF performance while supporting full-frame imaging.

The SQA85 utilizes a Petzval configuration, eliminating the need for back focus calculations—simply achieve focus within a connection distance of 40mm to 70mm for imaging. The lens hood is retractable, allowing for extension or retraction based on actual usage. The integrated dual-ring dovetail clamp features a hollow center section to reduce overall weight. Six M4 and M6 threaded holes are provided on the rings for mounting bases or dovetail plates to accommodate various accessories. The top handle incorporates a multi-function finder shoe for mounting a variety of astronomical accessories. The bottom dovetail plate is a standard Vixen-type 290mm dovetail plate.

The SQA85 features a dual-speed rack-and-pinion focuser with a large 2.8-inch high-rigidity design, compatible with most electronic focusers on the market. Focus travel is 32mm, and the focus tube is engraved with high-precision scale markings. Finder bases on both sides of the focuser provide additional mounting points for astronomical accessories without the need to remove or reposition finders. The rear end of the optical tube is equipped with multiple adapter rings featuring a knurled design for slip-free installation. Available thread specifications include M48, M54, and M68, allowing connection to a wide range of imaging accessories.