{"product_id":"zwo-ff70-apo-70mm-quadruplet-refractor","title":"ZWO FF70-APO 70mm Quadruplet Refractor F\/7.0","description":"\u003cul class=\"DAV-feature-list\"\u003e\n\u003cli\u003e70mm Aperture\u003c\/li\u003e\n\u003cli\u003e490mm Focal Length (f\/7)\u003c\/li\u003e\n\u003cli\u003e4-Element Quadruplet Optical Design\u003c\/li\u003e\n\u003cli\u003eIntegrated Field Flattener\u003c\/li\u003e\n\u003cli\u003e2.4\" Dual-Speed Rack \u0026amp; Pinion Focuser\u003c\/li\u003e\n\u003cli\u003e6.7 lb. Optical Tube 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\u003eZWO FF70-APO 70mm Quadruplet Refractor F\/7.0\u003c\/h2\u003e\n\u003cp\u003eThe ZWO FF70-APO combines a 70mm aperture with a 490mm focal length (f\/7) in a 4-element optical design that delivers a perfectly flat field without an external flattener. This quadruplet refractor weighs only 6.7 lbs., making it an ideal imaging instrument for lightweight, portable tracking mounts. The robust 2.4\" dual-speed focuser supports a full-frame camera payload without flexure, ensuring your stars remain sharp corner-to-corner.\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\u003e4-Element Design for Apochromatic, Flat-Field Imaging\u003c\/h3\u003e\n\u003cp\u003eThe FF70's quadruplet Petzval-style optical train is engineered for one primary purpose: wide-field astrophotography. By integrating the field flattening elements directly into the main optics, it eliminates the need to calculate back focus or purchase a separate flattener. As long as your camera can reach focus, the entire field is sharp, letting you frame large targets like the Andromeda Galaxy (M31) or the Orion Nebula (M42) across a full-frame sensor.\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\u003e2.4\" Dual-Speed Rack \u0026amp; Pinion Focuser\u003c\/h3\u003e\n\u003cp\u003eTo support modern imaging cameras and filter wheels, the FF70 is equipped with a rigid 2.4\" rack and pinion focuser. The dual-speed 1:10 fine adjustment knob gives you precise control for critical focusing, essential for capturing tight, point-like stars. The design minimizes backlash and sag, maintaining focus even with heavier imaging trains pointed near the zenith.\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\u003eZWO FF70 vs. FF90: Aperture vs. Portability\u003c\/h3\u003e\n\u003cp\u003eChoosing between ZWO's flat-field refractors involves a direct trade-off between light-gathering power and weight. The FF90 offers more aperture for resolving finer detail in galaxies and pulling in fainter nebulosity, but it weighs nearly 2 lbs. more and requires a more substantial mount. The FF70's primary advantage is its compact, 6.7 lb. form factor, which pairs perfectly with today's portable harmonic drive mounts or even heavy-duty star trackers for a true grab-and-go deep-sky imaging rig.\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\u003e6.7 lb. OTA for Grab-and-Go Astrophotography\u003c\/h3\u003e\n\u003cp\u003eAt a weight of only 6.7 lbs., the FF70 optical tube is built for portability. This low weight makes it accessible to a wide range of equatorial mounts, including compact trackers that might struggle with a larger, heavier refractor. The included 230mm Vixen-style dovetail plate, tube rings, and finderscope bases provide a solid foundation for attaching the scope and all necessary imaging accessories like a guide scope or ASIAIR.\u003c\/p\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\"\u003eDo I need a field flattener for the ZWO FF70 APO?\u003c\/h3\u003e\n\u003c\/div\u003e\n\u003cdiv class=\"DAV-accordion-A\"\u003e\n\u003cp\u003eNo. The ZWO FF70 APO has a \u003cstrong\u003e4-element Petzval optical design\u003c\/strong\u003e with an integrated flattener. This means you do not need to purchase a separate flattener or calculate a specific back focus distance. As long as your camera can achieve focus, the entire field will be corrected and flat.\u003c\/p\u003e\n\u003c\/div\u003e\n\u003cdiv class=\"DAV-accordion\"\u003e\n\u003ch3 class=\"DAV-accordion-Q\"\u003eHow does the ZWO FF70 APO perform on the North American Nebula (NGC 7000)?\u003c\/h3\u003e\n\u003c\/div\u003e\n\u003cdiv class=\"DAV-accordion-A\"\u003e\n\u003cp\u003eThe FF70's 490mm focal length is exceptionally well-suited for very large targets like the North American Nebula (NGC 7000). Paired with a full-frame camera, you can capture the entire nebula complex, including the adjacent Pelican Nebula (IC 5070), in a single frame with sharp stars across the field.\u003c\/p\u003e\n\u003c\/div\u003e\n\u003cdiv class=\"DAV-accordion\"\u003e\n\u003ch3 class=\"DAV-accordion-Q\"\u003eIs the 6.7 lb. weight of the FF70 APO suitable for a portable star tracker?\u003c\/h3\u003e\n\u003c\/div\u003e\n\u003cdiv class=\"DAV-accordion-A\"\u003e\n\u003cp\u003eYes, but only for the most capable models. While the 6.7 lb. optical tube weight is very low, you must also account for the weight of your camera, guide scope, and other accessories. For the best stability, a lightweight harmonic drive mount or a mid-range equatorial mount (such as one in the 25-30 lb. payload class) is recommended for serious imaging.\u003c\/p\u003e\n\u003c\/div\u003e\n\u003cdiv class=\"DAV-accordion\"\u003e\n\u003ch3 class=\"DAV-accordion-Q\"\u003eWhat cameras can I connect to the ZWO FF70 APO?\u003c\/h3\u003e\n\u003c\/div\u003e\n\u003cdiv class=\"DAV-accordion-A\"\u003e\n\u003cp\u003eThe FF70 is designed to be compatible with full-frame astronomy cameras and DSLRs\/mirrorless cameras. The included photographic extension tube provides standard M48x0.75 and M54x0.75 threads for easy connection to most dedicated astronomy cameras and T-rings.\u003c\/p\u003e\n\u003c\/div\u003e\n\u003cdiv class=\"DAV-accordion\"\u003e\n\u003ch3 class=\"DAV-accordion-Q\"\u003eWhat is the main difference between the ZWO FF70 and the FF90?\u003c\/h3\u003e\n\u003c\/div\u003e\n\u003cdiv class=\"DAV-accordion-A\"\u003e\n\u003cp\u003eThe primary differences are aperture and weight. The \u003cstrong\u003eZWO FF90\u003c\/strong\u003e has a larger 90mm aperture, giving it better light-gathering ability and higher resolution for smaller targets. The \u003cstrong\u003eZWO FF70\u003c\/strong\u003e is significantly lighter at 6.7 lbs. (compared to the FF90's 8.6 lbs.), making it a better choice for more portable setups and wider fields of view.\u003c\/p\u003e\n\u003c\/div\u003e\n\u003cdiv class=\"DAV-accordion\"\u003e\n\u003ch3 class=\"DAV-accordion-Q\"\u003eDoes the ZWO FF70 APO work for visual astronomy?\u003c\/h3\u003e\n\u003c\/div\u003e\n\u003cdiv class=\"DAV-accordion-A\"\u003e\n\u003cp\u003eWhile optimized for imaging, the FF70 is also a capable visual instrument. Its apochromatic optics provide high-contrast, color-correct views of star clusters, nebulae, and planets. You will need to add a 2\" diagonal and eyepiece to use it visually.\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\u003eSKU\u003c\/td\u003e\n\u003ctd\u003eZWO-FF70-APO\u003c\/td\u003e\n\u003c\/tr\u003e\n\u003ctr\u003e\n\u003ctd\u003eOptical Design\u003c\/td\u003e\n\u003ctd\u003eApochromatic Refractor\u003c\/td\u003e\n\u003c\/tr\u003e\n\u003ctr\u003e\n\u003ctd\u003eNumber of Elements\u003c\/td\u003e\n\u003ctd\u003e4 (Quadruplet)\u003c\/td\u003e\n\u003c\/tr\u003e\n\u003ctr\u003e\n\u003ctd\u003eAperture\u003c\/td\u003e\n\u003ctd\u003e70mm (2.8\")\u003c\/td\u003e\n\u003c\/tr\u003e\n\u003ctr\u003e\n\u003ctd\u003eFocal Length\u003c\/td\u003e\n\u003ctd\u003e490 mm\u003c\/td\u003e\n\u003c\/tr\u003e\n\u003ctr\u003e\n\u003ctd\u003eFocal Ratio\u003c\/td\u003e\n\u003ctd\u003ef\/7\u003c\/td\u003e\n\u003c\/tr\u003e\n\u003ctr\u003e\n\u003ctd\u003eFocuser\u003c\/td\u003e\n\u003ctd\u003e2.4\" Rack \u0026amp; Pinion\u003c\/td\u003e\n\u003c\/tr\u003e\n\u003ctr\u003e\n\u003ctd\u003eFocuser Speed\u003c\/td\u003e\n\u003ctd\u003eDual Speed 1:10\u003c\/td\u003e\n\u003c\/tr\u003e\n\u003ctr\u003e\n\u003ctd\u003eOTA Weight\u003c\/td\u003e\n\u003ctd\u003e6.7 lbs.\u003c\/td\u003e\n\u003c\/tr\u003e\n\u003ctr\u003e\n\u003ctd\u003eTelescope Series\u003c\/td\u003e\n\u003ctd\u003eZWO Refractors\u003c\/td\u003e\n\u003c\/tr\u003e\n\u003ctr\u003e\n\u003ctd\u003eMount Type\u003c\/td\u003e\n\u003ctd\u003eNo Mount - OTA Only\u003c\/td\u003e\n\u003c\/tr\u003e\n\u003ctr\u003e\n\u003ctd\u003eElectronics\u003c\/td\u003e\n\u003ctd\u003eOTA Only - No Electronics\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\"\u003eZWO 70 mm APO Refractor 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\"\u003eMounting Rings\u003c\/p\u003e\n\u003cp class=\"DAV-item-subtitle\"\u003e× 2\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\"\u003e230 mm Vixen Dovetail Plate\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\"\u003eFindershoes\u003c\/p\u003e\n\u003cp class=\"DAV-item-subtitle\"\u003e× 2\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\"\u003ePhotography Extension Tube\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\"\u003eWarranty Card\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\"\u003eInspection Card\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\"\u003eUser Manual\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:\/\/www.zwoastro.com\/software\/\" 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\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\u003ca href=\"https:\/\/davidastro.com\/pages\/zwo-warranty-policy\" rel=\"noopener\" target=\"_blank\"\u003eZWO 2-Year Warranty\u003c\/a\u003e\u003c\/li\u003e\n\u003c\/ul\u003e","brand":"ZWO","offers":[{"title":"Default Title","offer_id":51858426331421,"sku":"ZWO-FF70-APO","price":599.0,"currency_code":"USD","in_stock":true}],"thumbnail_url":"\/\/cdn.shopify.com\/s\/files\/1\/0753\/5280\/1565\/files\/ZWO-FF70-APO-Quadruplet-Refractor-1.jpg?v=1781058373","url":"https:\/\/davidastro.com\/fr-us\/products\/zwo-ff70-apo-70mm-quadruplet-refractor","provider":"David Astro","version":"1.0","type":"link"}