{"product_id":"askar-sqa85-85mm-f-4-8-quintuplet-apo","title":"Askar SQA85 85mm f\/4.8 Quintuplet APO","description":"\u003cul class=\"DAV-feature-list\"\u003e\n\u003cli\u003e85mm Aperture\u003c\/li\u003e\n\u003cli\u003e408mm Focal Length (f\/4.8)\u003c\/li\u003e\n\u003cli\u003eQuintuplet Petzval APO Optical Design\u003c\/li\u003e\n\u003cli\u003eSupports Full-Frame (44mm) Image Circle\u003c\/li\u003e\n\u003cli\u003e3.64kg OTA Weight\u003c\/li\u003e\n\u003c\/ul\u003e\n\u003c!-- more --\u003e\n\u003cul class=\"tabs\"\u003e\n\u003cli class=\"active\"\u003eDescription\u003c\/li\u003e\n\u003cli\u003eFAQ\u003c\/li\u003e\n\u003cli\u003eSpecifications\u003c\/li\u003e\n\u003cli\u003eIn the Box\u003c\/li\u003e\n\u003cli\u003eDownloads\u003c\/li\u003e\n\u003cli\u003eWarranty\u003c\/li\u003e\n\u003c\/ul\u003e\n\u003cul class=\"tabs-content\"\u003e\n\u003cli class=\"active\"\u003e\n\u003cdiv\u003e\n\u003cdiv class=\"DAV-bg-light\"\u003e\n\u003cdiv class=\"DAV-section-center\"\u003e\n\u003ch2\u003eAskar SQA85 85mm f\/4.8 Quintuplet APO\u003c\/h2\u003e\n\u003cp\u003eThe Askar SQA85 is a dedicated astrograph designed around a 5-element Petzval optical system, delivering a natively flat field at a fast f\/4.8 focal ratio from its 85mm objective. This 408mm focal length instrument incorporates two SD glass elements for superior color correction and illuminates a full-frame image circle without requiring a separate flattener. Weighing just 3.64kg and measuring a compact 403mm with its dew shield retracted, the SQA85 provides a powerful, portable imaging platform for capturing expansive celestial targets.\u003c\/p\u003e\n\u003c\/div\u003e\n\u003c\/div\u003e\n\u003cdiv class=\"DAV-bg-light\"\u003e\n\u003cdiv class=\"DAV-section\"\u003e\n\u003ch3\u003eNative f\/4.8 Petzval Optics: A Flat Field for Full-Frame Sensors\u003c\/h3\u003e\n\u003cp\u003eThe core of the SQA85 is its quintuplet Petzval APO objective, an integrated design that eliminates the need for a separate field flattener. This f\/4.8 system provides sharp, pinpoint stars across a full-frame sensor right out of the box. The 408mm focal length is ideal for framing large deep-sky objects like the Andromeda Galaxy (M31) or the entire Veil Nebula complex.\u003c\/p\u003e\n\u003cp\u003eTo ensure high-contrast images free of false color, the optical train includes two pieces of SD (Super ED) glass. This corrects for chromatic aberration, rendering stars as neutral white points against a dark sky background, which is critical for both broadband and narrowband imaging.\u003c\/p\u003e\n\u003c\/div\u003e\n\u003c\/div\u003e\n\u003cdiv class=\"DAV-bg-light\"\u003e\n\u003cdiv class=\"DAV-section\"\u003e\n\u003ch3\u003eImaging-Ready Mechanics: 3.64kg OTA with Versatile M48\/M54\/M68 Adapters\u003c\/h3\u003e\n\u003cp\u003eWith a bare optical tube assembly weight of 3.64kg, the SQA85 is light enough for a wide range of portable tracking mounts, minimizing payload demands while maximizing stability. The physical design is compact, with a total length of just 403mm when the dew shield is contracted, making it easy to transport and store.\u003c\/p\u003e\n\u003cp\u003eFor secure imaging train connections, the SQA85 includes M48, M54, and M68 adapters, allowing you to directly thread your filter wheel, off-axis guider, or camera. The system supports a back focus distance from 40mm to 70mm, with the standard 55mm being the recommended distance for use with most DSLR and dedicated astronomy cameras.\u003c\/p\u003e\n\u003c\/div\u003e\n\u003c\/div\u003e\n\u003cdiv class=\"DAV-bg-light\"\u003e\n\u003cdiv class=\"DAV-section\"\u003e\n\u003ch3\u003eSQA85 Petzval vs. Triplet + Flattener: The Simplicity of an Integrated System\u003c\/h3\u003e\n\u003cp\u003eWhile a traditional triplet refractor combined with a separate field flattener offers modularity, it also introduces complexity and potential sources of error. The primary advantage of the SQA85's integrated quintuplet Petzval design is the elimination of spacing guesswork and potential optical tilt between the objective and the corrector.\u003c\/p\u003e\n\u003cul\u003e\n\u003cli\u003e\n\u003cstrong\u003eTriplet + Flattener Trade-off:\u003c\/strong\u003e The main advantage of a modular system is the ability to use the telescope visually without the flattener. However, achieving a perfectly flat field for imaging requires precise, calculated spacing that can be difficult to dial in.\u003c\/li\u003e\n\u003cli\u003e\n\u003cstrong\u003eAskar SQA85 Advantage:\u003c\/strong\u003e As a single, factory-optimized system, the SQA85 guarantees flat-field performance. There is only one connection point to worry about—setting your camera sensor at the recommended 55mm back focus. This reduces potential flexure points and simplifies your setup, letting you spend more time imaging and less time troubleshooting star shapes.\u003c\/li\u003e\n\u003c\/ul\u003e\n\u003c\/div\u003e\n\u003c\/div\u003e\n\u003c\/div\u003e\n\u003c\/li\u003e\n\u003cli\u003e\n\u003cdiv class=\"DAV-accordion\"\u003e\n\u003ch3 class=\"DAV-accordion-Q\"\u003eWhat does the Quintuplet Petzval design of the Askar SQA85 mean for imaging?\u003c\/h3\u003e\n\u003c\/div\u003e\n\u003cdiv class=\"DAV-accordion-A\"\u003e\n\u003cp\u003eThe \u003cstrong\u003eQuintuplet Petzval\u003c\/strong\u003e design means the Askar SQA85 has a built-in field flattener. You do not need to purchase a separate corrector to get sharp, pinpoint stars across a full-frame sensor. It is an integrated imaging system designed to work perfectly right out of the box.\u003c\/p\u003e\n\u003c\/div\u003e\n\u003cdiv class=\"DAV-accordion\"\u003e\n\u003ch3 class=\"DAV-accordion-Q\"\u003eWhat kind of mount do I need for the Askar SQA85?\u003c\/h3\u003e\n\u003c\/div\u003e\n\u003cdiv class=\"DAV-accordion-A\"\u003e\n\u003cp\u003eThe SQA85 has an optical tube weight of \u003cstrong\u003e3.64kg\u003c\/strong\u003e and a gross weight of \u003cstrong\u003e4.62kg\u003c\/strong\u003e (including tube rings and a dovetail plate). A mid-sized equatorial mount with a payload capacity of 25-30 lbs (11-13 kg) or more, such as a Sky-Watcher HEQ5 or iOptron CEM26, would be an excellent match for stable, long-exposure astrophotography.\u003c\/p\u003e\n\u003c\/div\u003e\n\u003cdiv class=\"DAV-accordion\"\u003e\n\u003ch3 class=\"DAV-accordion-Q\"\u003eHow does the Askar SQA85's 408mm focal length perform on large targets like the Andromeda Galaxy (M31) with a full-frame camera?\u003c\/h3\u003e\n\u003c\/div\u003e\n\u003cdiv class=\"DAV-accordion-A\"\u003e\n\u003cp\u003eThe \u003cstrong\u003e408mm focal length\u003c\/strong\u003e is perfectly suited for this scenario. On a full-frame sensor, the Askar SQA85 will frame the entire Andromeda Galaxy (M31), including its satellite galaxies M32 and M110, with ample room to spare. This makes it an ideal instrument for capturing the full extent of large nebulae and galaxies.\u003c\/p\u003e\n\u003c\/div\u003e\n\u003cdiv class=\"DAV-accordion\"\u003e\n\u003ch3 class=\"DAV-accordion-Q\"\u003eHow do I connect my camera to the Askar SQA85?\u003c\/h3\u003e\n\u003c\/div\u003e\n\u003cdiv class=\"DAV-accordion-A\"\u003e\n\u003cp\u003eThe SQA85 includes \u003cstrong\u003eM48, M54, and M68\u003c\/strong\u003e threaded adapters at the rear. The most common connection is the M48x0.75 thread. You simply add the necessary extension tubes to place your camera's sensor at the recommended \u003cstrong\u003e55mm back focus distance\u003c\/strong\u003e from the adapter's flange.\u003c\/p\u003e\n\u003c\/div\u003e\n\u003cdiv class=\"DAV-accordion\"\u003e\n\u003ch3 class=\"DAV-accordion-Q\"\u003eIs the Askar SQA85's f\/4.8 focal ratio fast enough for narrowband imaging of the Cygnus Loop?\u003c\/h3\u003e\n\u003c\/div\u003e\n\u003cdiv class=\"DAV-accordion-A\"\u003e\n\u003cp\u003eAbsolutely. The \u003cstrong\u003ef\/4.8\u003c\/strong\u003e focal ratio is considered very fast for astrophotography. This speed allows you to gather significant signal in a shorter amount of time, which is a major advantage for narrowband imaging of faint targets like the Cygnus Loop. You can capture deep data with shorter sub-exposures compared to a slower f\/6 or f\/7 refractor.\u003c\/p\u003e\n\u003c\/div\u003e\n\u003cdiv class=\"DAV-accordion\"\u003e\n\u003ch3 class=\"DAV-accordion-Q\"\u003eWhat is the benefit of the two SD glass elements in the Askar SQA85 objective?\u003c\/h3\u003e\n\u003c\/div\u003e\n\u003cdiv class=\"DAV-accordion-A\"\u003e\n\u003cp\u003eThe two \u003cstrong\u003eSD (Super ED) glass elements\u003c\/strong\u003e provide excellent chromatic aberration correction. This means that different colors of light are brought to the same focal point, resulting in sharp, high-contrast images without distracting purple or blue halos around bright stars.\u003c\/p\u003e\n\u003c\/div\u003e\n\u003c\/li\u003e\n\u003cli\u003e\n\u003ctable class=\"DAV-specifications\"\u003e\n\u003ctbody\u003e\n\u003ctr\u003e\n\u003ctd\u003eAperture\u003c\/td\u003e\n\u003ctd\u003e85mm\u003c\/td\u003e\n\u003c\/tr\u003e\n\u003ctr\u003e\n\u003ctd\u003eFocal Length\u003c\/td\u003e\n\u003ctd\u003e408mm\u003c\/td\u003e\n\u003c\/tr\u003e\n\u003ctr\u003e\n\u003ctd\u003eFocal Ratio\u003c\/td\u003e\n\u003ctd\u003ef\/4.8\u003c\/td\u003e\n\u003c\/tr\u003e\n\u003ctr\u003e\n\u003ctd\u003eObjective Lens\u003c\/td\u003e\n\u003ctd\u003eQuintuplet Petzval APO (with 2 SD glass elements)\u003c\/td\u003e\n\u003c\/tr\u003e\n\u003ctr\u003e\n\u003ctd\u003eFormat \/ Image Circle\u003c\/td\u003e\n\u003ctd\u003eFull-frame (44mm)\u003c\/td\u003e\n\u003c\/tr\u003e\n\u003ctr\u003e\n\u003ctd\u003eOTA Weight\u003c\/td\u003e\n\u003ctd\u003e3.64kg\u003c\/td\u003e\n\u003c\/tr\u003e\n\u003ctr\u003e\n\u003ctd\u003eGross Weight\u003c\/td\u003e\n\u003ctd\u003e4.62kg (including tube ring and dovetail plate)\u003c\/td\u003e\n\u003c\/tr\u003e\n\u003ctr\u003e\n\u003ctd\u003eTotal Length\u003c\/td\u003e\n\u003ctd\u003e403mm (dew shield contracted) | 439mm (dew shield stretched)\u003c\/td\u003e\n\u003c\/tr\u003e\n\u003ctr\u003e\n\u003ctd\u003eRear-End Thread Adapters\u003c\/td\u003e\n\u003ctd\u003eM48, M54, M68\u003c\/td\u003e\n\u003c\/tr\u003e\n\u003ctr\u003e\n\u003ctd\u003eBack Focus\u003c\/td\u003e\n\u003ctd\u003e40mm - 70mm (55mm recommended)\u003c\/td\u003e\n\u003c\/tr\u003e\n\u003c\/tbody\u003e\n\u003c\/table\u003e\n\u003c\/li\u003e\n\u003cli\u003e\n\u003cul class=\"DAV-grid\"\u003e\n\u003cli class=\"DAV-grid-item\"\u003e\n\u003cdiv\u003e\n\u003cp class=\"DAV-item-title\"\u003eAskar SQA85 OTA\u003c\/p\u003e\n\u003cp class=\"DAV-item-subtitle\"\u003e× 1\u003c\/p\u003e\n\u003c\/div\u003e\n\u003c\/li\u003e\n\u003cli class=\"DAV-grid-item\"\u003e\n\u003cdiv\u003e\n\u003cp class=\"DAV-item-title\"\u003eOxford Cloth Case\u003c\/p\u003e\n\u003cp class=\"DAV-item-subtitle\"\u003e× 1\u003c\/p\u003e\n\u003c\/div\u003e\n\u003c\/li\u003e\n\u003c\/ul\u003e\n\u003c\/li\u003e\n\u003cli\u003e\n\u003cul class=\"DAV-grid\"\u003e\n\u003cli class=\"DAV-grid-item\"\u003e\u003ca href=\"https:\/\/cdn.shopify.com\/s\/files\/1\/0753\/5280\/1565\/files\/Askar_SQA85_Manual.pdf\" target=\"_blank\"\u003e\u003csvg class=\"DAV-img-box\" viewbox=\"0 0 512 512\" xmlns=\"http:\/\/www.w3.org\/2000\/svg\"\u003e\u003cpath d=\"M0 64C0 28.7 28.7 0 64 0L224 0l0 128c0 17.7 14.3 32 32 32l128 0 0 144-208 0c-35.3 0-64 28.7-64 64l0 144-48 0c-35.3 0-64-28.7-64-64L0 64zm384 64l-128 0L256 0 384 128zM176 352l32 0c30.9 0 56 25.1 56 56s-25.1 56-56 56l-16 0 0 32c0 8.8-7.2 16-16 16s-16-7.2-16-16l0-48 0-80c0-8.8 7.2-16 16-16zm32 80c13.3 0 24-10.7 24-24s-10.7-24-24-24l-16 0 0 48 16 0zm96-80l32 0c26.5 0 48 21.5 48 48l0 64c0 26.5-21.5 48-48 48l-32 0c-8.8 0-16-7.2-16-16l0-128c0-8.8 7.2-16 16-16zm32 128c8.8 0 16-7.2 16-16l0-64c0-8.8-7.2-16-16-16l-16 0 0 96 16 0zm80-112c0-8.8 7.2-16 16-16l48 0c8.8 0 16 7.2 16 16s-7.2 16-16 16l-32 0 0 32 32 0c8.8 0 16 7.2 16 16s-7.2 16-16 16l-32 0 0 48c0 8.8-7.2 16-16 16s-16-7.2-16-16l0-64 0-64z\" fill=\"#0047a7\"\u003e\u003c\/path\u003e\u003c\/svg\u003e\n\u003cdiv\u003e\n\u003cp class=\"DAV-item-title\"\u003eDownload Manual\u003c\/p\u003e\n\u003c\/div\u003e\n\u003c\/a\u003e\u003c\/li\u003e\n\u003cli class=\"DAV-grid-item\"\u003e\u003ca href=\"https:\/\/www.sharpstar-optics.com\/download_list_1\/7.html\" target=\"_blank\"\u003e\u003csvg xmlns=\"http:\/\/www.w3.org\/2000\/svg\" viewbox=\"0 0 640 512\" class=\"DAV-img-box\"\u003e\u003cpath fill=\"#0047a7\" d=\"M128 32C92.7 32 64 60.7 64 96l0 256 64 0 0-256 384 0 0 256 64 0 0-256c0-35.3-28.7-64-64-64L128 32zM19.2 384C8.6 384 0 392.6 0 403.2C0 445.6 34.4 480 76.8 480l486.4 0c42.4 0 76.8-34.4 76.8-76.8c0-10.6-8.6-19.2-19.2-19.2L19.2 384z\"\u003e\u003c\/path\u003e\u003c\/svg\u003e \n\u003cdiv\u003e\n\u003cp class=\"DAV-item-title\"\u003eDownload Software \u0026amp; Drivers\u003c\/p\u003e\n\u003c\/div\u003e\n\u003c\/a\u003e\u003c\/li\u003e\n\u003c\/ul\u003e\n\u003c\/li\u003e\n\u003cli\u003e\n\u003ca href=\"https:\/\/davidastro.com\/pages\/askar-warranty-policy\" rel=\"noopener\" target=\"_blank\"\u003eAskar 1-Year Warranty\u003c\/a\u003e\n\u003c\/li\u003e\n\u003c\/ul\u003e","brand":"Askar","offers":[{"title":"Default Title","offer_id":49200813867293,"sku":"ASK-SQA85","price":2395.0,"currency_code":"USD","in_stock":true}],"thumbnail_url":"\/\/cdn.shopify.com\/s\/files\/1\/0753\/5280\/1565\/files\/Askar-SQA85-1.jpg?v=1727373818","url":"https:\/\/davidastro.com\/fr-us\/products\/askar-sqa85-85mm-f-4-8-quintuplet-apo","provider":"David Astro","version":"1.0","type":"link"}