{"product_id":"askar-131f-flat-field-quadruplet-astrograph-askar-131f","title":"Askar 131F Flat-Field Quadruplet Astrograph | ASKAR-131F","description":"\u003cp\u003e\u003cimg src=\"https:\/\/cdn.shopify.com\/s\/files\/1\/0610\/7702\/9116\/files\/3d13b4c3-a038-41cf-a53a-6cd4aeb1dde7.jpg?v=1778276667\" alt=\"\"\u003e\u003c\/p\u003e\n\u003cp\u003eThe Askar 131F is a large-aperture telescope designed for astronomy enthusiasts, featuring a 131mm aperture, 983mm focal length, and a native F7.5 focal ratio.\u003c\/p\u003e\n\u003cp\u003eIt employs a quadruplet optical lens design with three elements in the front and one in the rear, including one piece of  ED glass to effectively suppress chromatic aberration. \u003c\/p\u003e\n\u003cp\u003eThe lens tube incorporates an internal baffle to block stray light, further enhancing image quality. The Askar 131F supports full-frame imaging and delivers excellent star performance across the frame.\u003c\/p\u003e\n\u003cp\u003e\u003cimg src=\"https:\/\/cdn.shopify.com\/s\/files\/1\/0610\/7702\/9116\/files\/8123866b-9cf3-4a57-ab98-ae6313f8a599.jpg?v=1778276667\" alt=\"\"\u003e\u003c\/p\u003e\n\u003cp\u003eContinuing the F series' self-flattening design, users can achieve optimal imaging without purchasing an additional flattener or calculating back focus. Simply connect the imaging accessory, achieve focus, and you're ready to shoot—streamlining the process and lowering the barrier to use.\u003c\/p\u003e\n\u003cp\u003eThe telescope comes standard with a photographic extension tube featuring a built-in 2-inch filter thread and offers M48×0.75 and M54×0.75 adapters for broad compatibility with DSLR cameras and dedicated astronomy cameras, meeting diverse imaging needs.\u003c\/p\u003e\n\u003cp\u003eStaying true to the brand philosophy, the Askar 131F balances optical performance with user experience. The lens tube is crafted with high-quality CNC machining and painted finish, continuing the F series' iconic blue-and-white color scheme for strong visual identity.\u003c\/p\u003e\n\u003cp\u003e\u003cimg src=\"https:\/\/cdn.shopify.com\/s\/files\/1\/0610\/7702\/9116\/files\/48a2d43f-cf6d-4c50-a39d-6b7bc5d8f6bd.jpg?v=1778276667\" alt=\"\"\u003e\u003c\/p\u003e\n\u003cp\u003eWhether for deep-sky imaging or visual observation, the Askar 131F is an ideal choice for advancing your astrophotography journey.\u003c\/p\u003e\n\u003cp\u003e\u003cimg src=\"https:\/\/cdn.shopify.com\/s\/files\/1\/0610\/7702\/9116\/files\/a91f8254-3b9e-4238-9ea1-896d6d9d6362.jpg?v=1778276666\" alt=\"\"\u003e\u003c\/p\u003e\n\u003cp\u003e\u003cimg src=\"https:\/\/cdn.shopify.com\/s\/files\/1\/0610\/7702\/9116\/files\/eab376d1-eedb-4162-b9f7-044457a71b0e.webp?v=1778276666\" alt=\"\"\u003e\u003c\/p\u003e\n\u003ch2\u003eSpecifications\u003c\/h2\u003e\n\u003ctable class=\"ck-table-resized\"\u003e\n\u003ctbody\u003e\n\u003ctr\u003e\n\u003ctd colspan=\"3\" class=\"responsive-title\"\u003e\u003cstrong\u003eParameters\u003c\/strong\u003e\u003c\/td\u003e\n\u003c\/tr\u003e\n\u003ctr\u003e\n\u003ctd\u003e\u003cstrong\u003eAperture size\u003c\/strong\u003e\u003c\/td\u003e\n\u003ctd colspan=\"2\"\u003e\u003cstrong\u003e131mm\u003c\/strong\u003e\u003c\/td\u003e\n\u003c\/tr\u003e\n\u003ctr\u003e\n\u003ctd\u003e\u003cstrong\u003eFocal length\u003c\/strong\u003e\u003c\/td\u003e\n\u003ctd colspan=\"2\"\u003e\u003cstrong\u003e983mm\u003c\/strong\u003e\u003c\/td\u003e\n\u003c\/tr\u003e\n\u003ctr\u003e\n\u003ctd\u003e\u003cstrong\u003eFocal ratio\u003c\/strong\u003e\u003c\/td\u003e\n\u003ctd colspan=\"2\"\u003e\u003cstrong\u003ef\/7.5\u003c\/strong\u003e\u003c\/td\u003e\n\u003c\/tr\u003e\n\u003ctr\u003e\n\u003ctd\u003e\u003cstrong\u003eObjective lens\u003c\/strong\u003e\u003c\/td\u003e\n\u003ctd colspan=\"2\"\u003e\u003cstrong\u003eQuadruplet air-spaced APO(including one ED glass)\u003c\/strong\u003e\u003c\/td\u003e\n\u003c\/tr\u003e\n\u003ctr\u003e\n\u003ctd\u003e\u003cstrong\u003eImage circle\u003c\/strong\u003e\u003c\/td\u003e\n\u003ctd colspan=\"2\"\u003e\u003cstrong\u003e44mm\u003c\/strong\u003e\u003c\/td\u003e\n\u003c\/tr\u003e\n\u003ctr\u003e\n\u003ctd\u003e\u003cstrong\u003eMaximum accessory connection (with the focuser fully retreated)\u003c\/strong\u003e\u003c\/td\u003e\n\u003ctd\u003e\n\u003cstrong\u003eImaging mode: \u003c\/strong\u003e \u003cbr\u003e\u003cstrong\u003e73mm (from the base of M48×0.75 male thread）\u003c\/strong\u003e \u003cbr\u003e\u003cstrong\u003e91mm（from the base of M54×0.75 male thread)\u003c\/strong\u003e\n\u003c\/td\u003e\n\u003ctd\u003e\n\u003cstrong\u003eObserving mode:  \u003c\/strong\u003e \u003cbr\u003e\u003cstrong\u003e131mm（from the end of 1.25\" eyepiece holder）\u003c\/strong\u003e \u003cbr\u003e\u003cstrong\u003e141mm（from the end of 2\" eyepiece holder）\u003c\/strong\u003e\n\u003c\/td\u003e\n\u003c\/tr\u003e\n\u003ctr\u003e\n\u003ctd\u003e\u003cstrong\u003eMinimum accessory connection (with the focuser fully extended)\u003c\/strong\u003e\u003c\/td\u003e\n\u003ctd\u003e\n\u003cstrong\u003eImaging mode: \u003c\/strong\u003e \u003cbr\u003e\u003cstrong\u003e43mm (from the base of M48×0.75 male thread）\u003c\/strong\u003e \u003cbr\u003e\u003cstrong\u003e61mm（from the base of M54×0.75 male thread)\u003c\/strong\u003e\n\u003c\/td\u003e\n\u003ctd\u003e\n\u003cstrong\u003eObserving mode:  \u003c\/strong\u003e \u003cbr\u003e\u003cstrong\u003e101mm（from the end of 1.25\" eyepiece holder）\u003c\/strong\u003e \u003cbr\u003e\u003cstrong\u003e111mm（from the end of 2\" eyepiece holder）\u003c\/strong\u003e\n\u003c\/td\u003e\n\u003c\/tr\u003e\n\u003ctr\u003e\n\u003ctd\u003e\u003cstrong\u003eTotal length\u003c\/strong\u003e\u003c\/td\u003e\n\u003ctd colspan=\"2\"\u003e\n\u003cstrong\u003e878mm(including 1.25\" adapter as dew shield contracted）\u003c\/strong\u003e \u003cbr\u003e\u003cstrong\u003e963mm(including 1.25\" adapter as dew shield fully stretched）\u003c\/strong\u003e \u003cbr\u003e\u003cstrong\u003e941mm(including the photographic adapter as dew shield contracted）\u003c\/strong\u003e \u003cbr\u003e\u003cstrong\u003e1026mm(including the photographic adapter as dew shield fully stretched）\u003c\/strong\u003e\n\u003c\/td\u003e\n\u003c\/tr\u003e\n\u003ctr\u003e\n\u003ctd\u003e\u003cstrong\u003eFocuser travel length\u003c\/strong\u003e\u003c\/td\u003e\n\u003ctd colspan=\"2\"\u003e\u003cstrong\u003e30mm\u003c\/strong\u003e\u003c\/td\u003e\n\u003c\/tr\u003e\n\u003ctr\u003e\n\u003ctd\u003e\u003cstrong\u003eNet weight\u003c\/strong\u003e\u003c\/td\u003e\n\u003ctd colspan=\"2\"\u003e\u003cstrong\u003e7.9kg\u003c\/strong\u003e\u003c\/td\u003e\n\u003c\/tr\u003e\n\u003ctr\u003e\n\u003ctd\u003e\u003cstrong\u003eGross weight (Including tube ring\u0026amp;dovetail plate)\u003c\/strong\u003e\u003c\/td\u003e\n\u003ctd colspan=\"2\"\u003e\u003cstrong\u003e9.4kg\u003c\/strong\u003e\u003c\/td\u003e\n\u003c\/tr\u003e\n\u003ctr\u003e\n\u003ctd\u003e\u003cstrong\u003eRear-end thread type\u003c\/strong\u003e\u003c\/td\u003e\n\u003ctd colspan=\"2\"\u003e\n\u003cstrong\u003eM78×1-M54×0.75        \u003c\/strong\u003e \u003cbr\u003e\u003cstrong\u003eM54×0.75-M54×0.75        \u003c\/strong\u003e \u003cbr\u003e\u003cstrong\u003eM54×0.75-M48×0.75  (with M48×0.75 filter thread)\u003c\/strong\u003e\n\u003c\/td\u003e\n\u003c\/tr\u003e\n\u003ctr\u003e\n\u003ctd\u003e\u003cstrong\u003eStandard package items\u003c\/strong\u003e\u003c\/td\u003e\n\u003ctd colspan=\"2\"\u003e\u003cstrong\u003e A 131F OTA，a pair of tube rings, a handle, a 300mm Losmandy dovetail plate,a set of photographic adapters\u003c\/strong\u003e\u003c\/td\u003e\n\u003c\/tr\u003e\n\u003c\/tbody\u003e\n\u003c\/table\u003e\n\u003cp\u003e\u003cbr\u003e\u003c\/p\u003e\n\u003cp\u003eProduct Size Diagram\u003c\/p\u003e\n\u003cp\u003e\u003cimg src=\"https:\/\/cdn.shopify.com\/s\/files\/1\/0610\/7702\/9116\/files\/8a883eef-96d8-4147-a206-fe1420dd4855.webp?v=1778276667\" alt=\"\"\u003e\u003c\/p\u003e\n\u003cp\u003e\u003cimg src=\"https:\/\/cdn.shopify.com\/s\/files\/1\/0610\/7702\/9116\/files\/a9e9b79d-844c-4873-9502-9cc87b6f3bf8.webp?v=1778276666\" alt=\"\"\u003e\u003cbr\u003eConnection Diagram\u003c\/p\u003e\n\u003cp\u003e\u003cimg src=\"https:\/\/cdn.shopify.com\/s\/files\/1\/0610\/7702\/9116\/files\/dbaae082-9703-4ccc-a319-b6dedcb3e3d8.webp?v=1778276666\" alt=\"\"\u003e\u003c\/p\u003e\n\u003cp\u003eThe Locking Screw Position Diagram\u003c\/p\u003e\n\u003cp\u003e\u003cimg src=\"https:\/\/cdn.shopify.com\/s\/files\/1\/0610\/7702\/9116\/files\/37f4ab88-3b9a-4c66-88f2-1674920272bb_1.webp?v=1778276666\" alt=\"\"\u003e\u003c\/p\u003e\n\u003cp\u003eElectronic Focuser Assembly Diagram\u003c\/p\u003e\n\u003cp\u003e\u003cimg src=\"https:\/\/cdn.shopify.com\/s\/files\/1\/0610\/7702\/9116\/files\/1acc5643-0b25-4789-a1b5-11c889ba55e2_1.webp?v=1778276667\" alt=\"\"\u003e\u003c\/p\u003e\n\u003cp\u003eOptical Path Diagram\u003c\/p\u003e\n\u003cp\u003e\u003cimg src=\"https:\/\/cdn.shopify.com\/s\/files\/1\/0610\/7702\/9116\/files\/e9cb86dc-bee7-488c-89ef-47160eaf5769.webp?v=1778276666\" alt=\"\"\u003e\u003c\/p\u003e\n\u003cp\u003eSpot Diagram\u003c\/p\u003e\n\u003cp\u003e\u003cimg src=\"https:\/\/cdn.shopify.com\/s\/files\/1\/0610\/7702\/9116\/files\/96389167-369e-4ff4-bbd2-43768e5ac17d_1.webp?v=1778276667\" alt=\"\"\u003e\u003c\/p\u003e","brand":"SharpStar","offers":[{"title":"Default Title","offer_id":49079559979260,"sku":"ASKAR-131F","price":2789.95,"currency_code":"CAD","in_stock":true}],"thumbnail_url":"\/\/cdn.shopify.com\/s\/files\/1\/0610\/7702\/9116\/files\/80faa908-794d-41fa-bb0f-83197b177116.webp?v=1778276510","url":"https:\/\/all-startelescope.com\/fr\/products\/askar-131f-flat-field-quadruplet-astrograph-askar-131f","provider":"All-Star Telescope Canada","version":"1.0","type":"link"}