{"id":14972,"date":"2026-05-08T16:55:07","date_gmt":"2026-05-08T14:55:07","guid":{"rendered":"https:\/\/deep-space-astronomy.ch\/?post_type=product&p=14972"},"modified":"2026-05-08T17:12:16","modified_gmt":"2026-05-08T15:12:16","slug":"askar-131f-flat-field","status":"publish","type":"product","link":"https:\/\/deep-space-astronomy.ch\/en\/product\/askar-131f-flat-field\/","title":{"rendered":"Askar 131F Flat-Field"},"content":{"rendered":"

Askar 131F Flat-Field - 131 mm Quadruplet Full Frame APO telescope for high-resolution astrophotography<\/h2>\n

L'Askar 131F Flat-Field<\/strong> is a large-diameter apochromatic refractor designed for demanding astrophotographers looking for advanced deep-sky performance. With its 131 mm<\/strong>, its focal length of 983 mm<\/strong> and its focal ratio of f\/7.5<\/strong>, It offers an ideal combination of resolution, optical correction and Full Frame compatibility.<\/p>\n

Thanks to its design self-correcting APO quadruplet<\/strong>, Askar 131F delivers fine, homogeneous stars across the entire field, without the need for additional flatteners or complex backfocus calculations. This approach considerably simplifies set-up while guaranteeing professional image quality.<\/p>\n

A Full Frame astrographic telescope designed for high resolution<\/h3>\n

The Askar 131F was developed for astronomers wishing to capture deep-sky objects with greater detail and resolution than with more compact scopes.<\/p>\n

With a focal length of almost 1 metre, it provides particularly good sampling for :<\/p>\n

    \n
  • Galaxies<\/li>\n
  • Compact nebulae<\/li>\n
  • Globular clusters<\/li>\n
  • Detailed HII regions<\/li>\n
  • Deep-sky objects requiring higher magnification<\/li>\n<\/ul>\n

    The image circle of 44 mm<\/strong> provides native compatibility with Full Frame sensors, while maintaining excellent optical performance right down to the corners.<\/p>\n

    APO quadruplet optics with ED glass<\/h3>\n

    The optical system is based on a formula quadruplet APO air-spaced<\/strong> including :<\/p>\n

      \n
    • Three front lenses<\/li>\n
    • A rear corrective lens<\/li>\n
    • An ED glass element<\/li>\n<\/ul>\n

      This design effectively reduces chromatic aberration and improves overall image contrast.<\/p>\n

      The tube also incorporates optimized internal diaphragms to limit stray reflections and maximize the quality of the photographic field.<\/p>\n

      The built-in corrector makes it extremely easy to use:<\/p>\n

        \n
      • No external flattener to buy<\/li>\n
      • No complex backfocus calculations<\/li>\n
      • Direct camera connection<\/li>\n
      • More compact and reliable setup<\/li>\n<\/ul>\n

        Full-frame astrophotography compatible<\/h3>\n

        The Askar 131F is supplied with several photographic adapters for excellent compatibility with modern equipment:<\/p>\n

          \n
        • M48x0.75<\/li>\n
        • M54x0.75<\/li>\n
        • Integrated 2-inch filter thread<\/li>\n<\/ul>\n

          This compatibility facilitates integration with :<\/p>\n

            \n
          • Astronomical CMOS cameras<\/li>\n
          • DSLR<\/li>\n
          • Hybrid cameras<\/li>\n
          • Filter wheels<\/li>\n
          • Standard accessories<\/li>\n<\/ul>\n

            The mechanical design limits bending and promotes precise optical alignment, essential for modern large-format sensors.<\/p>\n

            High-rigidity 3-inch Rack & Pinion eyepiece holder<\/h3>\n

            Askar 131F is equipped with a sturdy eyepiece holder 3-inch Rack & Pinion<\/strong>, designed to support heavy light trains while maintaining excellent stability.<\/p>\n

            This focuser includes :<\/p>\n

              \n
            • Fine 1:10 gear ratio<\/li>\n
            • Excellent mechanical rigidity<\/li>\n
            • 360\u00b0 graduated rotation<\/li>\n
            • Compatible with electronic focus motors<\/li>\n<\/ul>\n

              This design facilitates the extremely precise focusing required for high-resolution astrophotography.<\/p>\n

              Premium mechanical engineering<\/h3>\n

              The Askar 131F benefits from top-of-the-range CNC manufacturing with a particularly meticulous finish. The tube retains the elegant visual identity of the F series, with its blue and white finish.<\/p>\n

              The retractable mist guard improves transportability despite the instrument's large diameter.<\/p>\n

              The bezel also includes :<\/p>\n

                \n
              • A sturdy handle<\/li>\n
              • Accessory holders<\/li>\n
              • 300 mm Losmandy dovetail<\/li>\n
              • 1\/4\u201d and 3\/8\u201d threads\u201d<\/li>\n<\/ul>\n

                This configuration allows easy installation of :<\/p>\n

                  \n
                • Guides<\/li>\n
                • Researchers<\/li>\n
                • ASIAIR<\/li>\n
                • Focusing motors<\/li>\n
                • Advanced imaging accessories<\/li>\n<\/ul>\n

                  An ideal platform for astrophotography<\/h3>\n

                  With its 131 mm diameter and 983 mm focal length, the Askar 131F is a truly advanced astrophotography platform capable of accompanying high-end setups.<\/p>\n

                  It is ideal for users who want to :<\/p>\n

                    \n
                  • Gaining in resolution<\/li>\n
                  • Full Frame sensors<\/li>\n
                  • Capture more detail<\/li>\n
                  • Building an evolving, sustainable setup<\/li>\n<\/ul>\n

                    Summary table of technical specifications<\/h3>\n\n\n\n\n\n\n\n\n\n\n\n\n\n\n\n\n\n\n\n\n\n
                    Features<\/th>\nValue<\/th>\n<\/tr>\n
                    Optical type<\/td>\nQuadruplet APO air-spaced with ED glass<\/td>\n<\/tr>\n
                    Opening<\/td>\n131 mm<\/td>\n<\/tr>\n
                    Focal length<\/td>\n983 mm<\/td>\n<\/tr>\n
                    Focus report<\/td>\nf\/7.5<\/td>\n<\/tr>\n
                    Image circle<\/td>\n44 mm Full Frame<\/td>\n<\/tr>\n
                    Field corrector<\/td>\nIntegrated<\/td>\n<\/tr>\n
                    Lens holder<\/td>\n3\u2033 Rack & Pinion double speed<\/td>\n<\/tr>\n
                    Gearbox<\/td>\n1:10<\/td>\n<\/tr>\n
                    Rotation<\/td>\n360\u00b0 graduated<\/td>\n<\/tr>\n
                    Focuser stroke<\/td>\n30 mm<\/td>\n<\/tr>\n
                    Minimum length<\/td>\n878 mm<\/td>\n<\/tr>\n
                    Maximum length<\/td>\n1026 mm<\/td>\n<\/tr>\n
                    Net weight<\/td>\n7.9 kg<\/td>\n<\/tr>\n
                    Weight with collars and dovetail<\/td>\n9.4 kg<\/td>\n<\/tr>\n
                    Rear threads<\/td>\nM78, M54, M48<\/td>\n<\/tr>\n
                    Sensor compatibility<\/td>\nUp to Full Frame<\/td>\n<\/tr>\n
                    Dovetail<\/td>\nLosmandy 300 mm<\/td>\n<\/tr>\n
                    Adapters included<\/td>\nM48x0.75, M54x0.75, 2\u2033 filter thread<\/td>\n<\/tr>\n<\/tbody>\n<\/table>\n

                    Why choose Askar 131F?<\/h3>\n

                    The Askar 131F is a particularly interesting solution for astrophotographers looking for a high-performance Full Frame refractor with greater resolution and light-gathering capacity.<\/p>\n

                    Its modern optical formula, integrated corrector, robust mechanics and advanced compatibility make it an ideal platform for serious astrophotographic setups.<\/p>\n

                    Whether you're photographing detailed galaxies, complex nebulae or building a durable, scalable imaging setup, the Askar 131F is an extremely consistent, high-performance telescope.<\/p>","protected":false},"excerpt":{"rendered":"

                    Askar 131F Flat-Field \u2013 Lunette APO Quadruplet Full Frame 131 mm pour Astrophotographie Haute R\u00e9solution L\u2019Askar 131F Flat-Field est une lunette astronomique apochromatique de grand diam\u00e8tre con\u00e7ue pour les astrophotographes exigeants souhaitant acc\u00e9der \u00e0 un niveau de performance avanc\u00e9 en ciel profond. Avec son ouverture de 131 mm, sa focale de 983 mm et son […]<\/p>\n","protected":false},"featured_media":14973,"comment_status":"open","ping_status":"closed","template":"","meta":[],"product_brand":[382],"product_cat":[15],"product_tag":[],"class_list":{"0":"post-14972","1":"product","2":"type-product","3":"status-publish","4":"has-post-thumbnail","6":"product_brand-askar","7":"product_cat-non-classe","9":"first","10":"on_supplier","11":"taxable","12":"shipping-taxable","13":"purchasable","14":"product-type-simple"},"_links":{"self":[{"href":"https:\/\/deep-space-astronomy.ch\/en\/wp-json\/wp\/v2\/product\/14972","targetHints":{"allow":["GET"]}}],"collection":[{"href":"https:\/\/deep-space-astronomy.ch\/en\/wp-json\/wp\/v2\/product"}],"about":[{"href":"https:\/\/deep-space-astronomy.ch\/en\/wp-json\/wp\/v2\/types\/product"}],"replies":[{"embeddable":true,"href":"https:\/\/deep-space-astronomy.ch\/en\/wp-json\/wp\/v2\/comments?post=14972"}],"wp:featuredmedia":[{"embeddable":true,"href":"https:\/\/deep-space-astronomy.ch\/en\/wp-json\/wp\/v2\/media\/14973"}],"wp:attachment":[{"href":"https:\/\/deep-space-astronomy.ch\/en\/wp-json\/wp\/v2\/media?parent=14972"}],"wp:term":[{"taxonomy":"product_brand","embeddable":true,"href":"https:\/\/deep-space-astronomy.ch\/en\/wp-json\/wp\/v2\/product_brand?post=14972"},{"taxonomy":"product_cat","embeddable":true,"href":"https:\/\/deep-space-astronomy.ch\/en\/wp-json\/wp\/v2\/product_cat?post=14972"},{"taxonomy":"product_tag","embeddable":true,"href":"https:\/\/deep-space-astronomy.ch\/en\/wp-json\/wp\/v2\/product_tag?post=14972"}],"curies":[{"name":"wp","href":"https:\/\/api.w.org\/{rel}","templated":true}]}}