{"title":"SharpStar Newtonian Astrographs (HNT, PNT)","description":"\u003cp\u003eSharpStar Newtonian astrographs are very fast reflectors built for deep-sky imaging. The HNT models, a 130mm and a 150mm at f\/2.8, use a hyperbolic primary mirror with a dedicated corrector to reach very short exposure times. The PNT 200mm f\/3.2 uses a parabolic primary and gathers more light for galaxies and faint nebulae.\u003c\/p\u003e\u003cp\u003eAt these focal ratios, precise collimation, a rigid focuser and a camera with correct back focus matter, so they suit imagers with some experience.\u003c\/p\u003e","products":[{"product_id":"sharpstar-150mm-f-2-8-hnt-hyperbolic-newtonian-astrograph","title":"SharpStar 150mm f\/2.8 HNT Hyperbolic Newtonian Astrograph","description":"\u003cul class=\"DAV-feature-list\"\u003e\n\u003cli\u003eAperture: 150mm\u003c\/li\u003e\n\u003cli\u003eFocal Ratio: f\/2.8\u003c\/li\u003e\n\u003cli\u003eImage Circle: 44mm\u003c\/li\u003e\n\u003cli\u003eGross Weight: 6 kg\u003c\/li\u003e\n\u003cli\u003eBack-Focus: 55mm\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\u003eSharpStar 150mm f\/2.8 HNT Hyperbolic Newtonian Astrograph\u003c\/h2\u003e\n\u003cp\u003eThe SharpStar 150mm f\/2.8 HNT Hyperbolic Newtonian Astrograph is an imaging instrument engineered for speed, delivering a 420mm focal length at an exceptionally fast f\/2.8 focal ratio. Its 150mm hyperbolic primary mirror and integrated corrector produce a flat, fully illuminated 44mm image circle, covering full-frame sensors with a vast 6-degree field of view. The entire system, including the tube ring and dovetail plate, weighs just 6kg, making it a portable solution for wide-field deep-sky astrophotography.\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\u003e150mm f\/2.8 Hyperbolic Optics: A 44mm Flat-Field System\u003c\/h3\u003e\n\u003cp\u003eThe optical core of the 150HNT is its 150mm hyperbolic primary mirror, which achieves a native f\/2.8 focal ratio. Unlike a standard parabolic mirror, a hyperbolic figure is designed to work as part of a system with a dedicated corrector, enabling superior off-axis correction across a large 44mm image circle. The primary mirror is made from PZ33, a low-expansion Pyrex-type glass that ensures thermal stability as ambient temperatures change.\u003c\/p\u003e\n\u003cp\u003eBoth the primary and 70mm secondary mirrors feature enhanced aluminum coatings, guaranteeing light reflectivity of over 96%. This high throughput, combined with the fast focal ratio, allows you to capture faint details with significantly shorter exposure times, maximizing the data collected during clear nights.\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\u003eIntegrated 3-Element Corrector for a 6° Field of View\u003c\/h3\u003e\n\u003cp\u003eTo deliver its expansive 6-degree field of view, the 150HNT incorporates a three-element, air-spaced corrector directly into the focuser assembly. This design, which includes one ED (Extra-low Dispersion) glass element, is optimized specifically for the hyperbolic primary, eliminating coma and ensuring pinpoint stars to the edge of a full-frame sensor. By integrating the corrector, the system removes the complexity of matching a third-party coma corrector and guarantees the specified 55mm back-focus distance.\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\u003eRigid 2-Speed Focuser for Precise Control\u003c\/h3\u003e\n\u003cp\u003eAn astrograph's focuser must be rigid enough to carry a modern imaging train without flexure. The 150HNT is equipped with a dual-speed rack-and-pinion focuser capable of supporting a 3kg payload. The focuser includes a built-in camera rotator for effortless framing and is compatible with most electronic auto-focusers.\u003c\/p\u003e\n\u003cp\u003eMechanical stability is reinforced throughout the optical tube. The CNC-machined secondary mirror support is a single, rigid piece designed to prevent misalignment and produce clean, sharp diffraction spikes. The primary mirror cell features three sets of adjustment screws for precise and stable collimation.\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\u003eAstrograph-Ready Build: 6 kg Total Weight with Rings \u0026amp; Plate\u003c\/h3\u003e\n\u003cp\u003eDesigned for portability and rapid deployment, the SharpStar 150HNT has a total weight of just 6kg, including its tube rings and a 200mm Losmandy-style dovetail plate. The compact 443mm tube length makes it easy to balance on a wide range of equatorial mounts. The package also includes a 200mm handle bar that adds rigidity and provides a convenient mounting point for guide scopes or other accessories via its integrated finder base.\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\u003eSharpStar 15028HNT vs. Standard 6\" f\/4 Newtonians: Speed and Correction\u003c\/h3\u003e\n\u003cp\u003eWhile a standard 6\" f\/4 Newtonian is a capable imaging instrument, the SharpStar 150HNT is purpose-built for a higher tier of astrophotography. The primary differences lie in optical speed and field correction.\u003c\/p\u003e\n\u003cul\u003e\n\u003cli\u003e\n\u003cstrong\u003eExposure Time:\u003c\/strong\u003e At f\/2.8, the 150HNT gathers light approximately twice as fast as an f\/4 system. This means a 5-minute exposure on the 150HNT collects the same signal as a 10-minute exposure on an f\/4 scope, effectively doubling your imaging efficiency.\u003c\/li\u003e\n\u003cli\u003e\n\u003cstrong\u003eIntegrated Correction:\u003c\/strong\u003e The 150HNT's hyperbolic mirror and built-in corrector are designed as a single optical system to produce a flat 44mm field. A standard f\/4 Newtonian requires a separate, often generic, coma corrector that may not fully correct the field or illuminate a full-frame sensor without vignetting.\u003c\/li\u003e\n\u003cli\u003e\n\u003cstrong\u003eOptical Design:\u003c\/strong\u003e The hyperbolic design allows for sharper stars at the edge of the field compared to what a standard parabolic mirror and separate corrector can typically achieve, especially on large sensors.\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 kind of mount is required for the SharpStar 150mm HNT?\u003c\/h3\u003e\n\u003c\/div\u003e\n\u003cdiv class=\"DAV-accordion-A\"\u003e\n\u003cp\u003eWith a gross weight of \u003cstrong\u003e6kg\u003c\/strong\u003e (including rings and dovetail), the SharpStar 150HNT is well-suited for mid-range equatorial mounts. For optimal tracking and guiding, a mount in the payload class of a Sky-Watcher HEQ5, iOptron CEM26, or larger is recommended, especially once a camera and guide scope are added.\u003c\/p\u003e\n\u003c\/div\u003e\n\u003cdiv class=\"DAV-accordion\"\u003e\n\u003ch3 class=\"DAV-accordion-Q\"\u003eWhat is the advantage of a hyperbolic primary mirror in the 150mm HNT?\u003c\/h3\u003e\n\u003c\/div\u003e\n\u003cdiv class=\"DAV-accordion-A\"\u003e\n\u003cp\u003eA hyperbolic mirror is part of a more advanced optical design than the parabolic mirrors found in standard Newtonians. It is specifically figured to work in tandem with the built-in \u003cstrong\u003ethree-element corrector\u003c\/strong\u003e to achieve a wider, flatter, and better-corrected field of view across its \u003cstrong\u003e44mm image circle\u003c\/strong\u003e than a parabolic mirror with a separate, general-purpose coma corrector.\u003c\/p\u003e\n\u003c\/div\u003e\n\u003cdiv class=\"DAV-accordion\"\u003e\n\u003ch3 class=\"DAV-accordion-Q\"\u003eHow do I set the correct 55mm back-focus for my camera with the SharpStar 150mm HNT?\u003c\/h3\u003e\n\u003c\/div\u003e\n\u003cdiv class=\"DAV-accordion-A\"\u003e\n\u003cp\u003eThe standard \u003cstrong\u003e55mm back-focus\u003c\/strong\u003e is measured from the base of the M48x0.75 male thread on the focuser's camera rotator. To achieve this distance, you will use a combination of extension tubes and adapters, such as an M48 T-ring for your DSLR or a set of spacers for a dedicated astronomy camera, to place your camera's sensor at the correct distance.\u003c\/p\u003e\n\u003c\/div\u003e\n\u003cdiv class=\"DAV-accordion\"\u003e\n\u003ch3 class=\"DAV-accordion-Q\"\u003eHow will the SharpStar 150mm HNT frame large targets like the North American Nebula (NGC 7000)?\u003c\/h3\u003e\n\u003c\/div\u003e\n\u003cdiv class=\"DAV-accordion-A\"\u003e\n\u003cp\u003eThe SharpStar 150HNT is ideal for such targets. With its \u003cstrong\u003e420mm focal length\u003c\/strong\u003e and \u003cstrong\u003e6-degree field of view\u003c\/strong\u003e on a full-frame sensor, it can easily capture the entirety of the North American Nebula (NGC 7000) and the neighboring Pelican Nebula (IC 5070) in a single, richly detailed frame.\u003c\/p\u003e\n\u003c\/div\u003e\n\u003cdiv class=\"DAV-accordion\"\u003e\n\u003ch3 class=\"DAV-accordion-Q\"\u003eIs the SharpStar 150mm HNT suitable for imaging small galaxies like the Whirlpool Galaxy (M51)?\u003c\/h3\u003e\n\u003c\/div\u003e\n\u003cdiv class=\"DAV-accordion-A\"\u003e\n\u003cp\u003eWhile the 150HNT can certainly image the Whirlpool Galaxy (M51), its wide \u003cstrong\u003e420mm focal length\u003c\/strong\u003e is optimized for large nebulae and star fields. M51 will appear relatively small in the frame. The astrograph's strength is capturing such galaxies within the context of their surrounding galactic cirrus and stellar environment, rather than for high-magnification detail.\u003c\/p\u003e\n\u003c\/div\u003e\n\u003cdiv class=\"DAV-accordion\"\u003e\n\u003ch3 class=\"DAV-accordion-Q\"\u003eCan I use an electronic autofocuser (EAF) with the SharpStar 150mm HNT?\u003c\/h3\u003e\n\u003c\/div\u003e\n\u003cdiv class=\"DAV-accordion-A\"\u003e\n\u003cp\u003eYes. The dual-speed rack-and-pinion focuser on the 150HNT is designed to be compatible with most common electronic auto-focusers (EAFs). This allows for precise, automated focusing which is critical for a fast f\/2.8 system where the critical focus zone is very narrow.\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 Size\u003c\/td\u003e\n\u003ctd\u003e150mm\u003c\/td\u003e\n\u003c\/tr\u003e\n\u003ctr\u003e\n\u003ctd\u003eFocal Length\u003c\/td\u003e\n\u003ctd\u003e420mm\u003c\/td\u003e\n\u003c\/tr\u003e\n\u003ctr\u003e\n\u003ctd\u003eFocal Ratio\u003c\/td\u003e\n\u003ctd\u003ef\/2.8\u003c\/td\u003e\n\u003c\/tr\u003e\n\u003ctr\u003e\n\u003ctd\u003eImage Circle\u003c\/td\u003e\n\u003ctd\u003e44mm\u003c\/td\u003e\n\u003c\/tr\u003e\n\u003ctr\u003e\n\u003ctd\u003eField of View\u003c\/td\u003e\n\u003ctd\u003e6 degrees\u003c\/td\u003e\n\u003c\/tr\u003e\n\u003ctr\u003e\n\u003ctd\u003eBack-Focus\u003c\/td\u003e\n\u003ctd\u003e55mm\u003c\/td\u003e\n\u003c\/tr\u003e\n\u003ctr\u003e\n\u003ctd\u003ePrimary Mirror Type\u003c\/td\u003e\n\u003ctd\u003eHyperbolic reflective mirror\u003c\/td\u003e\n\u003c\/tr\u003e\n\u003ctr\u003e\n\u003ctd\u003ePrimary Mirror Material\u003c\/td\u003e\n\u003ctd\u003ePZ33 (Pyrex-type glass)\u003c\/td\u003e\n\u003c\/tr\u003e\n\u003ctr\u003e\n\u003ctd\u003eCorrector\u003c\/td\u003e\n\u003ctd\u003eThree-element air-spaced (inc. one ED element)\u003c\/td\u003e\n\u003c\/tr\u003e\n\u003ctr\u003e\n\u003ctd\u003eSecondary Mirror Minor Axis\u003c\/td\u003e\n\u003ctd\u003e70mm\u003c\/td\u003e\n\u003c\/tr\u003e\n\u003ctr\u003e\n\u003ctd\u003eResolution\u003c\/td\u003e\n\u003ctd\u003e0.77 arc seconds\u003c\/td\u003e\n\u003c\/tr\u003e\n\u003ctr\u003e\n\u003ctd\u003eLimiting Visual Magnitude\u003c\/td\u003e\n\u003ctd\u003e12.7\u003c\/td\u003e\n\u003c\/tr\u003e\n\u003ctr\u003e\n\u003ctd\u003eOTA Weight\u003c\/td\u003e\n\u003ctd\u003e4.8kg\u003c\/td\u003e\n\u003c\/tr\u003e\n\u003ctr\u003e\n\u003ctd\u003eGross Weight\u003c\/td\u003e\n\u003ctd\u003e6kg (including tube ring and dovetail plate)\u003c\/td\u003e\n\u003c\/tr\u003e\n\u003ctr\u003e\n\u003ctd\u003eMain Tube Material\u003c\/td\u003e\n\u003ctd\u003eAluminum\u003c\/td\u003e\n\u003c\/tr\u003e\n\u003ctr\u003e\n\u003ctd\u003eMain Tube Outer Diameter\u003c\/td\u003e\n\u003ctd\u003e193mm\u003c\/td\u003e\n\u003c\/tr\u003e\n\u003ctr\u003e\n\u003ctd\u003eMain Tube Length\u003c\/td\u003e\n\u003ctd\u003e443mm\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\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\/SharpStar_15028HNT-AL_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":"SharpStar Optics","offers":[{"title":"Default Title","offer_id":44967747715357,"sku":"SSO-15028HNT-AL","price":2765.0,"currency_code":"CAD","in_stock":true}],"thumbnail_url":"\/\/cdn.shopify.com\/s\/files\/1\/0753\/5280\/1565\/files\/SSO-15028HNT-AL.png?v=1755111762"},{"product_id":"sharpstar-200mm-f-3-2-pnt-parabolic-newtonian-astrograph","title":"SharpStar 200mm f\/3.2 PNT Parabolic Newtonian Astrograph","description":"\u003c!-- more --\u003e\u003cdiv\u003e\n\u003cdiv\u003e\n\u003cspan\u003eSHARPSTAR's newly developed ultra-short focal ratio paraboloid Newtonian reflector 20032PNT was launched, which filled a domestic gap in this field. The focal ratio of the whole system reached F3.2 by using a 200mmF3.8 paraboloid, a 90mm plane secondary mirror of short axis, and a 3-inch quartette 0.85 times error correction mirror, has been leading in the domestic market of similar products. Carbon fiber main tube is light, durable and so elegant appearance, which uses Pyrex materials is more stable than conventional reflective materials.\u003c\/span\u003e\u003cbr\u003e\u003cspan\u003e  The primary and secondary mirrors are all made of reinforced aluminum coating, and the reflectivity is ensured to be above 96%. The secondary mirror cross is formed once to ensure firm and not deformed. 3-inch special geared focuser device to ensure the attachment when shooting without slipping, and smooth operation.\u003c\/span\u003e\u003cbr\u003e\u003cspan\u003e  The whole CNC aluminum parts and hollow out type tube ring, the novel handle will improve the appearance and mechanical quality to a new height, making the overall look more close to the needs of enthusiasts.\u003c\/span\u003e\u003cbr\u003e\u003cspan\u003e  The optical path also contains a quartette image-field correction mirror, which, in combination with the system, ensures full field photography and excellent peripheral reduction control, easy access to most of the imaging terminals on the market and perfect focusing with the M54×0.75 threaded at the end of the focuser and the 55mm focal plane (M48×0.75 thread with 52mm rear focal length).\u003c\/span\u003e\n\u003c\/div\u003e\n\u003cdiv\u003e\u003cspan\u003e\u003cimg src=\"https:\/\/cdn.shopify.com\/s\/files\/1\/0753\/5280\/1565\/t\/7\/assets\/description_image_SharpStar_20032PNT_Spot.jpg?v=1684345756\" alt=\"\"\u003e\u003c\/span\u003e\u003c\/div\u003e\n\u003cdiv\u003e\u003cspan\u003e\u003cimg src=\"https:\/\/cdn.shopify.com\/s\/files\/1\/0753\/5280\/1565\/t\/7\/assets\/description_image_SharpStar_20032PNT_Dimensions_1.jpg?v=1684345757\" alt=\"\"\u003e\u003c\/span\u003e\u003c\/div\u003e\n\u003cdiv\u003e\u003cspan\u003e\u003cimg src=\"https:\/\/cdn.shopify.com\/s\/files\/1\/0753\/5280\/1565\/t\/7\/assets\/description_image_SharpStar_20032PNT_Dimensions_2.jpg?v=1684345758\" alt=\"\" width=\"1028\" height=\"665\"\u003e\u003c\/span\u003e\u003c\/div\u003e\n\u003c\/div\u003e\u003cdiv data-custom-tab\u003e\n\u003cp data-custom-tab-title\u003eSpecifications\u003c\/p\u003e\n\u003cdiv\u003e\u003cp\u003eAperture: 200mm\u003cbr\u003eFocal Length: 760mm\u003cbr\u003eFocal Ratio: f\/3.8\u003cbr\u003ePrimary Mirror Type: Paraboloid\u003cbr\u003eMirror Material: PZ33 (similar as Pyrex glass)\u003cbr\u003eCorrector Type: Quartette air spaced\u003cbr\u003eSystem Focal Length\/ ratio: 640mm\/3.2\u003cbr\u003eShort axis diameter of secondary mirror: 90mm\u003cbr\u003eFully illuminated image circle: 44mm\u003cbr\u003eActual field: 3.76° (complete)\u003cbr\u003eMain tube material: Carbon fiber\u003cbr\u003eMain tube outer diameter: 280.5mm\u003cbr\u003eTotal length of telescope: 633m\u003cbr\u003eNet weight: 8kg\u003cbr\u003eGross weight: 9.46kg (including tube cap, handle, tube rings and dovetail plate)\u003cbr\u003eResolution: 0.6 arc-seconds\u003cbr\u003eFocuser: 3\" precision Focuser\u003cbr\u003eVisual Limiting Star Magnitude: 13.2\u003cbr\u003eFocal plane: 55mm (start from the end face of M54 thread)\u003c\/p\u003e\u003c\/div\u003e\n\u003c\/div\u003e","brand":"SharpStar Optics","offers":[{"title":"Default Title","offer_id":44967748862237,"sku":"SSO-20032PNT","price":4193.0,"currency_code":"CAD","in_stock":false}],"thumbnail_url":"\/\/cdn.shopify.com\/s\/files\/1\/0753\/5280\/1565\/products\/SharpStar-20032PNT-1__57523.1609100072.1280.1280.jpg?v=1684345775"},{"product_id":"sharpstar-130mm-f-2-8-hnt-hyperbolic-newtonian-astrograph","title":"SharpStar 130mm f\/2.8 HNT Hyperbolic Newtonian Astrograph","description":"\u003cul class=\"DAV-feature-list\"\u003e\n\u003cli\u003e130mm Hyperbolic Newtonian Optics\u003c\/li\u003e\n\u003cli\u003e364mm Focal Length\u003c\/li\u003e\n\u003cli\u003ef\/2.8 Focal Ratio\u003c\/li\u003e\n\u003cli\u003e44mm Full-Frame Image Circle\u003c\/li\u003e\n\u003cli\u003eTotal Assembled Weight: 4.8kg\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\u003eSharpStar 130mm f\/2.8 HNT Hyperbolic Newtonian Astrograph\u003c\/h2\u003e\n\u003cp\u003eThe SharpStar 130mm f\/2.8 HNT Astrograph combines a 130mm hyperbolic primary mirror with a 364mm focal length to achieve its native f\/2.8 optical speed. It illuminates a full 44mm image circle, covering modern full-frame sensors with a vast 6.9-degree field of view and resolving details down to 0.89 arc seconds. Weighing just 4.8kg with its rings and plate, this astrograph provides this wide-field imaging capability in a compact 400mm tube length.\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\u003ef\/2.8 Hyperbolic Optics: 130mm Aperture at 364mm Focal Length\u003c\/h3\u003e\n\u003cp\u003eAt the core of the 130HNT is a fast, light-gathering optical system designed for one purpose: deep-sky imaging. The 130mm hyperbolic primary mirror, made from low-expansion PZ33 glass, works in tandem with a two-element corrector to deliver sharp stars across the field. This f\/2.8 focal ratio allows you to capture faint details in nebulae and galaxies with significantly shorter exposure times compared to slower f\/5 or f\/7 systems.\u003c\/p\u003e\n\u003cul\u003e\n\u003cli\u003e\n\u003cstrong\u003eEnhanced Coatings:\u003c\/strong\u003e Both the primary and secondary mirrors feature an enhanced aluminum coating, ensuring reflectivity greater than 96% for brighter images and better signal-to-noise ratio.\u003c\/li\u003e\n\u003cli\u003e\n\u003cstrong\u003ePZ33 Primary Mirror:\u003c\/strong\u003e The Pyrex-like PZ33 mirror material minimizes thermal expansion and contraction, helping the telescope maintain focus as ambient temperatures change during an imaging session.\u003c\/li\u003e\n\u003cli\u003e\n\u003cstrong\u003eCorrected Field:\u003c\/strong\u003e The corrector assembly includes an ED (Extra-low Dispersion) glass element to suppress chromatic aberration, ensuring star colors are rendered accurately without distracting halos.\u003c\/li\u003e\n\u003c\/ul\u003e\n\u003c\/div\u003e\n\u003c\/div\u003e\n\u003cdiv class=\"DAV-bg-light\"\u003e\n\u003cdiv class=\"DAV-section\"\u003e\n\u003ch3\u003e44mm Image Circle for 6.9° Wide-Field Views\u003c\/h3\u003e\n\u003cp\u003eThe 130HNT is engineered to fully illuminate a 44mm image circle, making it an ideal match for full-frame DSLR, mirrorless, and dedicated astronomy cameras. A 65mm secondary mirror ensures there is no vignetting across these large sensors. This expansive 6.9-degree field of view lets you frame enormous targets like the Andromeda Galaxy (M31) or the entire North American Nebula (NGC 7000) in a single shot.\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\u003eA Rigid 4.8kg System with CNC-Machined Components\u003c\/h3\u003e\n\u003cp\u003eAn astrograph's mechanical stability is just as critical as its optical design. The SharpStar 130HNT is built from all-metal components, featuring a rigid aluminum main tube and CNC-machined parts for the focuser, secondary bracket, and mirror cell. This construction ensures precise, repeatable collimation and minimizes mechanical flexure, even with a heavy imaging payload.\u003c\/p\u003e\n\u003cul\u003e\n\u003cli\u003e\n\u003cstrong\u003eStable Secondary Bracket:\u003c\/strong\u003e The integrated, CNC-machined secondary mirror bracket is designed for rigidity, which not only holds collimation but also produces clean, sharp diffraction spikes on bright stars.\u003c\/li\u003e\n\u003cli\u003e\n\u003cstrong\u003e3-Point Primary Cell:\u003c\/strong\u003e The primary mirror cell features three sets of adjustment screws for precise collimation, ensuring you can align the optical system for peak performance.\u003c\/li\u003e\n\u003cli\u003e\n\u003cstrong\u003eLightweight Rings:\u003c\/strong\u003e The included tube rings have a hollowed-out design to reduce weight without sacrificing strength, bringing the total assembled weight to a portable 4.8kg.\u003c\/li\u003e\n\u003c\/ul\u003e\n\u003c\/div\u003e\n\u003c\/div\u003e\n\u003cdiv class=\"DAV-bg-light\"\u003e\n\u003cdiv class=\"DAV-section\"\u003e\n\u003ch3\u003e3kg Capacity Focuser with Integrated Rotator and 55mm Back Focus\u003c\/h3\u003e\n\u003cp\u003eThe imaging train is managed by a heavy-duty, dual-speed rack-and-pinion focuser designed to carry a payload of up to 3kg. This robust focuser can easily support a full-frame camera, filter wheel, and off-axis guider without slipping or tilting. An integrated 360° camera rotator allows you to frame your target perfectly without loosening any other components, while the standard 55mm back focus simplifies the process of connecting your camera and accessories using standard M48 spacers.\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\u003eSharpStar 130HNT vs. 130mm APO Refractors: The f\/2.8 Advantage\u003c\/h3\u003e\n\u003cp\u003eWhile a 130mm apochromatic refractor offers a maintenance-free, sealed optical tube, the SharpStar 130HNT provides a decisive advantage in speed. A typical 130mm APO has a focal ratio around f\/7, whereas the 130HNT operates at f\/2.8.\u003c\/p\u003e\n\u003cul\u003e\n\u003cli\u003e\n\u003cstrong\u003eExposure Time:\u003c\/strong\u003e The f\/2.8 system gathers light over six times faster than an f\/7 system. An 1-minute exposure on the 130HNT collects the same amount of signal as a 6-minute exposure on the refractor, allowing you to complete projects in a fraction of the time.\u003c\/li\u003e\n\u003cli\u003e\n\u003cstrong\u003eField of View:\u003c\/strong\u003e With its 364mm focal length, the 130HNT delivers a much wider field of view than a 130mm refractor, which typically has a focal length over 900mm.\u003c\/li\u003e\n\u003cli\u003e\n\u003cstrong\u003eTrade-off:\u003c\/strong\u003e The Newtonian design requires periodic collimation to maintain peak optical alignment, a step not needed with a refractor. However, for imagers prioritizing speed and field of view, this is a manageable trade-off for the dramatic reduction in exposure time.\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 makes the SharpStar 130HNT's f\/2.8 speed so important for astrophotography?\u003c\/h3\u003e\n\u003c\/div\u003e\n\u003cdiv class=\"DAV-accordion-A\"\u003e\n\u003cp\u003eAn \u003cstrong\u003ef\/2.8 focal ratio\u003c\/strong\u003e dramatically reduces the exposure time needed to capture faint deep-sky objects. Compared to a more common f\/5.6 instrument, it gathers light four times faster. This means you can capture more data in a single night, improve your signal-to-noise ratio, and place less demand on your tracking mount.\u003c\/p\u003e\n\u003c\/div\u003e\n\u003cdiv class=\"DAV-accordion\"\u003e\n\u003ch3 class=\"DAV-accordion-Q\"\u003eHow does the SharpStar 130HNT's 44mm image circle perform on large targets like the Andromeda Galaxy (M31)?\u003c\/h3\u003e\n\u003c\/div\u003e\n\u003cdiv class=\"DAV-accordion-A\"\u003e\n\u003cp\u003eThe \u003cstrong\u003e44mm image circle\u003c\/strong\u003e is designed for full-frame sensors. Combined with the 364mm focal length, this provides a massive 6.9-degree field of view. This is wide enough to capture the entire Andromeda Galaxy (M31) and its satellite galaxies, M32 and M110, with plenty of surrounding space, making it ideal for large-scale mosaics and framing the biggest nebulae.\u003c\/p\u003e\n\u003c\/div\u003e\n\u003cdiv class=\"DAV-accordion\"\u003e\n\u003ch3 class=\"DAV-accordion-Q\"\u003eDo I need to collimate the SharpStar 130HNT, and is it difficult?\u003c\/h3\u003e\n\u003c\/div\u003e\n\u003cdiv class=\"DAV-accordion-A\"\u003e\n\u003cp\u003eYes, as a Newtonian reflector, the \u003cstrong\u003eSharpStar 130HNT requires collimation\u003c\/strong\u003e to ensure the mirrors are perfectly aligned for sharp images. The primary mirror features three sets of user-friendly adjustment screws. While it requires a laser collimator or cheshire eyepiece, the process is straightforward and essential for achieving the telescope's specified 0.89 arc second resolution.\u003c\/p\u003e\n\u003c\/div\u003e\n\u003cdiv class=\"DAV-accordion\"\u003e\n\u003ch3 class=\"DAV-accordion-Q\"\u003eCan the 3kg focuser capacity of the SharpStar 130HNT handle a full-frame camera, filter wheel, and off-axis guider?\u003c\/h3\u003e\n\u003c\/div\u003e\n\u003cdiv class=\"DAV-accordion-A\"\u003e\n\u003cp\u003eAbsolutely. The \u003cstrong\u003e3kg payload capacity\u003c\/strong\u003e of the dual-speed rack-and-pinion focuser is specifically designed for modern imaging setups. A typical full-frame cooled CMOS camera, 7-position filter wheel, and an off-axis guider will fall well within this limit, preventing focuser sag or tilt during long exposures.\u003c\/p\u003e\n\u003c\/div\u003e\n\u003cdiv class=\"DAV-accordion\"\u003e\n\u003ch3 class=\"DAV-accordion-Q\"\u003eWhat is the standard 55mm back focus on the SharpStar 130HNT, and why does it matter?\u003c\/h3\u003e\n\u003c\/div\u003e\n\u003cdiv class=\"DAV-accordion-A\"\u003e\n\u003cp\u003eThe \u003cstrong\u003e55mm back focus\u003c\/strong\u003e is the standardized distance required between the focuser's M48 thread and your camera's sensor for the optical corrector to work properly. This standard is used by most DSLRs (with a T-ring) and dedicated astronomy cameras, making it easy to achieve the correct spacing without complex calculations or custom adapters.\u003c\/p\u003e\n\u003c\/div\u003e\n\u003cdiv class=\"DAV-accordion\"\u003e\n\u003ch3 class=\"DAV-accordion-Q\"\u003eWhat are the benefits of the PZ33 primary mirror in the SharpStar 130HNT?\u003c\/h3\u003e\n\u003c\/div\u003e\n\u003cdiv class=\"DAV-accordion-A\"\u003e\n\u003cp\u003e\u003cstrong\u003ePZ33\u003c\/strong\u003e is a borosilicate glass similar to Pyrex, with a very low coefficient of thermal expansion. This means as the temperature drops overnight, the mirror's shape remains stable, preventing the focus from shifting. This is a critical feature for maintaining sharp stars over a long imaging session.\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 Size\u003c\/td\u003e\n\u003ctd\u003e130mm\u003c\/td\u003e\n\u003c\/tr\u003e\n\u003ctr\u003e\n\u003ctd\u003eFocal Length\u003c\/td\u003e\n\u003ctd\u003e364mm\u003c\/td\u003e\n\u003c\/tr\u003e\n\u003ctr\u003e\n\u003ctd\u003eFocal Ratio\u003c\/td\u003e\n\u003ctd\u003ef\/2.8\u003c\/td\u003e\n\u003c\/tr\u003e\n\u003ctr\u003e\n\u003ctd\u003eImage Circle\u003c\/td\u003e\n\u003ctd\u003e44mm\u003c\/td\u003e\n\u003c\/tr\u003e\n\u003ctr\u003e\n\u003ctd\u003eField of View\u003c\/td\u003e\n\u003ctd\u003e6.9°\u003c\/td\u003e\n\u003c\/tr\u003e\n\u003ctr\u003e\n\u003ctd\u003eResolution\u003c\/td\u003e\n\u003ctd\u003e0.89 arc second\u003c\/td\u003e\n\u003c\/tr\u003e\n\u003ctr\u003e\n\u003ctd\u003eLimiting Visual Magnitude\u003c\/td\u003e\n\u003ctd\u003e12.3\u003c\/td\u003e\n\u003c\/tr\u003e\n\u003ctr\u003e\n\u003ctd\u003ePrimary Mirror Type\u003c\/td\u003e\n\u003ctd\u003eHyperbolic reflective mirror\u003c\/td\u003e\n\u003c\/tr\u003e\n\u003ctr\u003e\n\u003ctd\u003ePrimary Mirror Material\u003c\/td\u003e\n\u003ctd\u003ePZ33 (similar to Pyrex glass)\u003c\/td\u003e\n\u003c\/tr\u003e\n\u003ctr\u003e\n\u003ctd\u003eSecondary Mirror Minor Axis\u003c\/td\u003e\n\u003ctd\u003e65mm\u003c\/td\u003e\n\u003c\/tr\u003e\n\u003ctr\u003e\n\u003ctd\u003eCorrector\u003c\/td\u003e\n\u003ctd\u003eTwo-element air-spaced refractive lenses (one ED glass)\u003c\/td\u003e\n\u003c\/tr\u003e\n\u003ctr\u003e\n\u003ctd\u003eBack Focus\u003c\/td\u003e\n\u003ctd\u003e55mm\u003c\/td\u003e\n\u003c\/tr\u003e\n\u003ctr\u003e\n\u003ctd\u003eMain Tube Material\u003c\/td\u003e\n\u003ctd\u003eAluminum\u003c\/td\u003e\n\u003c\/tr\u003e\n\u003ctr\u003e\n\u003ctd\u003eMain Tube Outer Diameter\u003c\/td\u003e\n\u003ctd\u003e174mm\u003c\/td\u003e\n\u003c\/tr\u003e\n\u003ctr\u003e\n\u003ctd\u003eMain Tube Length\u003c\/td\u003e\n\u003ctd\u003e400mm\u003c\/td\u003e\n\u003c\/tr\u003e\n\u003ctr\u003e\n\u003ctd\u003eOTA Weight\u003c\/td\u003e\n\u003ctd\u003e3.8kg\u003c\/td\u003e\n\u003c\/tr\u003e\n\u003ctr\u003e\n\u003ctd\u003eTotal Weight (with Rings \u0026amp; Plate)\u003c\/td\u003e\n\u003ctd\u003e4.8kg\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\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:\/\/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\"\u003eSharpStar\/Askar 1-Year Warranty\u003c\/a\u003e\n\u003c\/li\u003e\n\u003c\/ul\u003e","brand":"SharpStar Optics","offers":[{"title":"Default Title","offer_id":44968028766493,"sku":"SSO-13028HNT-AL","price":2303.0,"currency_code":"CAD","in_stock":true}],"thumbnail_url":"\/\/cdn.shopify.com\/s\/files\/1\/0753\/5280\/1565\/files\/SSO-13028HNT-AL.jpg?v=1755111542"}],"url":"https:\/\/davidastro.com\/collections\/sharpstar-newtonian-astrographs-hnt-pnt.oembed","provider":"David Astro","version":"1.0","type":"link"}