{"title":"ZWO FF Apochromatic Refractors","description":"\u003cp\u003eZWO FF apochromatic refractors are quadruplet designs with a built-in flattening element, so they deliver a flat field for astrophotography without a separate flattener. The range covers the FF70-APO at f\/7.0, FF90-APO at f\/6.8, FF110-APO at f\/7.0 and FF131-APO at f\/7.5.\u003c\/p\u003e\u003cp\u003eMatching reducers shorten the focal ratio for faster imaging: a 0.75x full-frame reducer for the FF65, a 0.76x for the FF80 and a 0.7x universal reducer for the FF107 and FF130.\u003c\/p\u003e","products":[{"product_id":"zwo-ff65-apo-075x-full-frame-reducer","title":"ZWO FF65 APO 0.75× Full Frame Reducer","description":"\u003cul class=\"DAV-feature-list\"\u003e\n\u003cli\u003eReduces FF65 APO focal ratio to f\/4.8\u003c\/li\u003e\n\u003cli\u003e0.75x reduction factor for wider fields of view\u003c\/li\u003e\n\u003cli\u003eStandard 55mm back focus from the M48 thread\u003c\/li\u003e\n\u003cli\u003eIntegrated M48x0.75 (2-inch) filter thread\u003c\/li\u003e\n\u003cli\u003eQuad-element design for full-frame correction\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 0.75x Full-Frame Reducer for FF65-APO Refractor\u003c\/h2\u003e\n\u003cp\u003eThe ZWO 0.75x Full-Frame Reducer transforms the FF65-APO into a faster f\/4.8 imaging system, using a four-element optical design to achieve wider fields of view. This 0.75x reduction factor allows you to capture large targets with significantly shorter exposure times, while the standard 55mm back focus ensures compatibility with your existing full-frame camera and filter setup via the included M48 adapter.\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\u003eAchieve a Faster f\/4.8 Focal Ratio\u003c\/h3\u003e\n\u003cp\u003eBy shortening the native focal ratio of the FF65-APO, this 0.75x reducer gathers light more quickly, effectively reducing total integration time required for faint deep-sky objects. An f\/4.8 system is substantially faster than the telescope's original configuration, letting you complete projects in a fraction of the time and maximize data collection on clear nights. This speed is critical for capturing faint nebulosity in targets like the North America Nebula (NGC 7000) or the Heart Nebula (IC 1805).\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\u003eFull-Frame Correction with 55mm Back Focus\u003c\/h3\u003e\n\u003cp\u003eEngineered with a quad-element optical layout, the reducer maintains sharp, well-corrected stars across a full-frame sensor. It establishes a standard 55mm back focus distance from the base of its M48 threads, simplifying camera and accessory connection. This industry-standard spacing is designed to accommodate a DSLR with a T-ring, or a dedicated astronomy camera with a filter wheel and off-axis guider, without complex calculations.\u003c\/p\u003e\n\u003cul\u003e\n\u003cli\u003e\n\u003cstrong\u003eStandardized Connection:\u003c\/strong\u003e The 55mm spacing allows for direct attachment of most ZWO ASI cameras and filter wheels, creating a rigid, threaded imaging train.\u003c\/li\u003e\n\u003cli\u003e\n\u003cstrong\u003eFour-Element Design:\u003c\/strong\u003e Corrects for optical aberrations introduced by the reduction process, ensuring stars remain tight and round to the edge of the frame.\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\u003eIntegrated 2-inch Filter Thread and Adapters\u003c\/h3\u003e\n\u003cp\u003eThe reducer includes both M54 and M48 threaded adapters for direct, secure attachment to the FF65-APO focuser and your camera system. An M48x0.75 (2-inch) filter thread is built into the included camera-side adapter, allowing you to place light pollution or narrowband filters directly into the optical path. This placement is ideal for minimizing reflections and vignetting, especially with fast f\/4.8 optics.\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\"\u003eWhat does the ZWO 0.75x Reducer do to the FF65-APO's focal length?\u003c\/h3\u003e\n\u003c\/div\u003e\n\u003cdiv class=\"DAV-accordion-A\"\u003e\n\u003cp\u003eThe ZWO 0.75x Reducer shortens the FF65-APO's native 416mm focal length to approximately 312mm. This creates a much wider field of view, allowing you to frame large celestial objects like the Andromeda Galaxy (M31) or the entire Veil Nebula complex in a single shot with a full-frame sensor.\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 ZWO F65RE Reducer?\u003c\/h3\u003e\n\u003c\/div\u003e\n\u003cdiv class=\"DAV-accordion-A\"\u003e\n\u003cp\u003eThe reducer provides a standard \u003cstrong\u003e55mm back focus\u003c\/strong\u003e from its M48x0.75 male threads. You can connect your ZWO camera, filter wheel, and off-axis guider using the appropriate M48 spacers to achieve this 55mm distance. For a DSLR, a standard M48 T-ring will typically provide the correct spacing automatically.\u003c\/p\u003e\n\u003c\/div\u003e\n\u003cdiv class=\"DAV-accordion\"\u003e\n\u003ch3 class=\"DAV-accordion-Q\"\u003eCan I use 2-inch filters with this ZWO reducer?\u003c\/h3\u003e\n\u003c\/div\u003e\n\u003cdiv class=\"DAV-accordion-A\"\u003e\n\u003cp\u003eYes. The included camera-side adapter has a female M48x0.75 filter thread, designed to accept standard 2-inch astronomy filters. This allows you to easily add light pollution, L-Pro, or narrowband filters to your imaging train.\u003c\/p\u003e\n\u003c\/div\u003e\n\u003cdiv class=\"DAV-accordion\"\u003e\n\u003ch3 class=\"DAV-accordion-Q\"\u003eIs this reducer compatible with telescopes other than the ZWO FF65-APO?\u003c\/h3\u003e\n\u003c\/div\u003e\n\u003cdiv class=\"DAV-accordion-A\"\u003e\n\u003cp\u003eNo, this 0.75x reducer is optically matched specifically for the ZWO FF65-APO refractor. Using it with other telescopes will likely result in poor optical correction, field curvature, and stars that are not sharp at the edge of the field.\u003c\/p\u003e\n\u003c\/div\u003e\n\u003cdiv class=\"DAV-accordion\"\u003e\n\u003ch3 class=\"DAV-accordion-Q\"\u003eDoes the ZWO F65RE reducer change the image circle?\u003c\/h3\u003e\n\u003c\/div\u003e\n\u003cdiv class=\"DAV-accordion-A\"\u003e\n\u003cp\u003eThe reducer is designed to provide excellent illumination and correction across a full-frame sensor (44mm image circle) when paired with the FF65-APO. It maintains the telescope's full-frame imaging capability while making the field of view wider.\u003c\/p\u003e\n\u003c\/div\u003e\n\u003cdiv class=\"DAV-accordion\"\u003e\n\u003ch3 class=\"DAV-accordion-Q\"\u003eHow much faster is f\/4.8 compared to the FF65's native f\/6.4 for imaging the Orion Nebula (M42)?\u003c\/h3\u003e\n\u003c\/div\u003e\n\u003cdiv class=\"DAV-accordion-A\"\u003e\n\u003cp\u003eAn f\/4.8 system is approximately 1.78 times faster than an f\/6.4 system. This means that for a target like the Orion Nebula (M42), an exposure that would take 180 seconds at f\/6.4 would only require about 101 seconds at f\/4.8 to achieve the same signal level, allowing you to gather more data in less time.\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-F65RE\u003c\/td\u003e\n\u003c\/tr\u003e\n\u003ctr\u003e\n\u003ctd\u003eReduction Factor\u003c\/td\u003e\n\u003ctd\u003e0.75x\u003c\/td\u003e\n\u003c\/tr\u003e\n\u003ctr\u003e\n\u003ctd\u003eResulting Focal Ratio\u003c\/td\u003e\n\u003ctd\u003ef\/4.8 (with FF65-APO)\u003c\/td\u003e\n\u003c\/tr\u003e\n\u003ctr\u003e\n\u003ctd\u003eOptical Design\u003c\/td\u003e\n\u003ctd\u003e4-element\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\u003eFilter Thread\u003c\/td\u003e\n\u003ctd\u003eM48x0.75 (2-inch)\u003c\/td\u003e\n\u003c\/tr\u003e\n\u003ctr\u003e\n\u003ctd\u003eAdapters Included\u003c\/td\u003e\n\u003ctd\u003eM54 and M48\u003c\/td\u003e\n\u003c\/tr\u003e\n\u003ctr\u003e\n\u003ctd\u003eCompatibility\u003c\/td\u003e\n\u003ctd\u003eZWO FF65-APO Refractor\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\"\u003e0.75x Full-Frame Reducer for FF65-APO\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\"\u003eM54 Adapter\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\"\u003eM48 Adapter\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\"\u003eDust Caps\u003c\/p\u003e\n\u003cp class=\"DAV-item-subtitle\"\u003e× 2\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 Limited Warranty\u003c\/a\u003e\u003c\/li\u003e\n\u003c\/ul\u003e","brand":"ZWO","offers":[{"title":"Default Title","offer_id":49552485351709,"sku":"ZWO-F65RE","price":279.0,"currency_code":"CAD","in_stock":false}],"thumbnail_url":"\/\/cdn.shopify.com\/s\/files\/1\/0753\/5280\/1565\/files\/88c326eaab7f5daa2b9a92756386c1ea.jpg?v=1736329728"},{"product_id":"zwo-ff80-apo-0-76-full-frame-reducer","title":"ZWO FF80 APO 0.76× Full Frame Reducer","description":"\u003cul class=\"DAV-feature-list\"\u003e\n\u003cli\u003e0.76x focal reduction factor\u003c\/li\u003e\n\u003cli\u003eDesigned for the ZWO FF80-APO Refractor\u003c\/li\u003e\n\u003cli\u003eTriplet optical design with one ED element\u003c\/li\u003e\n\u003cli\u003eStandard 55 mm back focus\u003c\/li\u003e\n\u003cli\u003eIntegrated M48x0.75 thread for 2\" filters\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 0.76x Full-Frame Reducer for FF80-APO Refractor\u003c\/h2\u003e\n\u003cp\u003eThe ZWO 0.76x Full-Frame Reducer is the factory-matched optical modifier for the FF80-APO refractor, shortening its focal length for wider fields and faster data acquisition. Its 3-element optical path uses one ED glass element to maintain the APO's sharp, high-contrast performance across a full-frame sensor. With a standard 55 mm back focus and integrated M48x0.75 threads for 2\" filters, this 3\" reducer integrates seamlessly into common imaging trains.\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\u003e0.76x Reduction for Wider, Faster Imaging\u003c\/h3\u003e\n\u003cp\u003eBy reducing the FF80-APO's native focal length by a factor of 0.76x, this accessory dramatically expands your field of view. This allows you to frame large targets like the Andromeda Galaxy (M31) or the Heart Nebula (IC 1805) in their entirety. The reduction in f-ratio also concentrates incoming light, significantly cutting down the required exposure time for each sub-frame and letting you capture more data in a single night.\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\u003eTriplet ED Optics for Edge-to-Edge Correction at 55 mm\u003c\/h3\u003e\n\u003cp\u003eA simple reducer can compromise the performance of a high-end refractor by introducing chromatic aberration and coma. This ZWO reducer employs a sophisticated triplet lens design with one Extra-low Dispersion (ED) glass element to counteract these effects. The result is a flat, well-corrected field with sharp stars to the edge of a full-frame sensor, preserving the apochromatic correction of the FF80-APO. The design achieves this correction while maintaining the industry-standard 55 mm back focus, ensuring compatibility with DSLRs, mirrorless cameras, and dedicated astronomy cameras with filter wheels.\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 M48x0.75 Threads for 2\" Filters\u003c\/h3\u003e\n\u003cp\u003eThe reducer features an M48x0.75 female filter thread on the camera side, allowing you to directly mount any standard 2\" filter. This provides a secure, tilt-free way to incorporate nebula or light pollution filters into your optical train. Placing the filter at the camera-side end of the reducer optimizes the light path and often helps achieve focus with accessories that have tight spacing requirements.\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\"\u003eWhat does the ZWO 0.76x reducer do for my FF80-APO?\u003c\/h3\u003e\n\u003c\/div\u003e\n\u003cdiv class=\"DAV-accordion-A\"\u003e\n\u003cp\u003eIt reduces the telescope's focal length, which has two primary benefits. First, it creates a \u003cstrong\u003ewider true field of view\u003c\/strong\u003e, allowing you to fit larger deep-sky objects into your frame. Second, it creates a \u003cstrong\u003efaster focal ratio\u003c\/strong\u003e, which reduces the exposure time needed to capture faint details, letting you gather more data in less time.\u003c\/p\u003e\n\u003c\/div\u003e\n\u003cdiv class=\"DAV-accordion\"\u003e\n\u003ch3 class=\"DAV-accordion-Q\"\u003eIs the back focus fixed at 55 mm with the FF80 reducer?\u003c\/h3\u003e\n\u003c\/div\u003e\n\u003cdiv class=\"DAV-accordion-A\"\u003e\n\u003cp\u003eYes. The optical design is optimized for a precise \u003cstrong\u003e55 mm distance\u003c\/strong\u003e from the reducer's rear mounting flange to your camera's sensor. This is a standard spacing for most dedicated astronomy cameras and for DSLRs\/mirrorless cameras using a standard 48 mm T-ring.\u003c\/p\u003e\n\u003c\/div\u003e\n\u003cdiv class=\"DAV-accordion\"\u003e\n\u003ch3 class=\"DAV-accordion-Q\"\u003eHow does the reducer's triplet ED design improve my images?\u003c\/h3\u003e\n\u003c\/div\u003e\n\u003cdiv class=\"DAV-accordion-A\"\u003e\n\u003cp\u003eThe triplet design, which includes one \u003cstrong\u003eExtra-low Dispersion (ED) element\u003c\/strong\u003e, is corrective. It ensures that the wider, faster image remains sharp and free of false color (chromatic aberration) from the center to the corners of the field. It preserves the high-quality apochromatic performance of the FF80-APO telescope itself.\u003c\/p\u003e\n\u003c\/div\u003e\n\u003cdiv class=\"DAV-accordion\"\u003e\n\u003ch3 class=\"DAV-accordion-Q\"\u003eCan I use 2\" filters with this ZWO reducer?\u003c\/h3\u003e\n\u003c\/div\u003e\n\u003cdiv class=\"DAV-accordion-A\"\u003e\n\u003cp\u003eYes. The reducer has a built-in \u003cstrong\u003eM48x0.75 female thread\u003c\/strong\u003e, which is the standard for 2\" astronomy filters. You can thread your filter directly into the camera-side end of the reducer for a secure connection.\u003c\/p\u003e\n\u003c\/div\u003e\n\u003cdiv class=\"DAV-accordion\"\u003e\n\u003ch3 class=\"DAV-accordion-Q\"\u003eHow does this 0.76x reducer help when imaging the Andromeda Galaxy (M31) with the FF80-APO?\u003c\/h3\u003e\n\u003c\/div\u003e\n\u003cdiv class=\"DAV-accordion-A\"\u003e\n\u003cp\u003eThe Andromeda Galaxy (M31) is a very large target, spanning about 3 degrees of the sky. The 0.76x reducer widens the FF80-APO's field of view enough to frame the entire galaxy, including its faint outer arms and satellite galaxies M32 and M110, in a single shot with a full-frame camera.\u003c\/p\u003e\n\u003c\/div\u003e\n\u003cdiv class=\"DAV-accordion\"\u003e\n\u003ch3 class=\"DAV-accordion-Q\"\u003eWill the FF80 reducer be useful for large emission nebulae like the North America Nebula (NGC 7000)?\u003c\/h3\u003e\n\u003c\/div\u003e\n\u003cdiv class=\"DAV-accordion-A\"\u003e\n\u003cp\u003eAbsolutely. For sprawling H-alpha targets like the North America Nebula (NGC 7000), the 0.76x reducer is essential. It allows you to capture the full extent of the nebula and the adjacent Pelican Nebula (IC 5070) in one frame, while the faster focal ratio significantly reduces the long exposure times typically required for narrowband imaging.\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-F80RE\u003c\/td\u003e\n\u003c\/tr\u003e\n\u003ctr\u003e\n\u003ctd\u003eOptical Design\u003c\/td\u003e\n\u003ctd\u003e3-Element (Triplet) with one ED element\u003c\/td\u003e\n\u003c\/tr\u003e\n\u003ctr\u003e\n\u003ctd\u003eReduction Factor\u003c\/td\u003e\n\u003ctd\u003e0.76x\u003c\/td\u003e\n\u003c\/tr\u003e\n\u003ctr\u003e\n\u003ctd\u003eCompatible Telescope\u003c\/td\u003e\n\u003ctd\u003eZWO FF80-APO Refractor\u003c\/td\u003e\n\u003c\/tr\u003e\n\u003ctr\u003e\n\u003ctd\u003eBack Focus\u003c\/td\u003e\n\u003ctd\u003e55 mm\u003c\/td\u003e\n\u003c\/tr\u003e\n\u003ctr\u003e\n\u003ctd\u003eBarrel Size\u003c\/td\u003e\n\u003ctd\u003e3\"\u003c\/td\u003e\n\u003c\/tr\u003e\n\u003ctr\u003e\n\u003ctd\u003eFilter Compatibility\u003c\/td\u003e\n\u003ctd\u003eM48x0.75 thread for 2\" filters\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\"\u003e0.76x Reducer for FF80-APO\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\"\u003eFront Dust Cap\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\"\u003eRear Dust Cap\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 Limited Warranty\u003c\/a\u003e\u003c\/li\u003e\n\u003c\/ul\u003e","brand":"ZWO","offers":[{"title":"Default Title","offer_id":49552527229213,"sku":"ZWO-F80RE","price":349.0,"currency_code":"CAD","in_stock":true}],"thumbnail_url":"\/\/cdn.shopify.com\/s\/files\/1\/0753\/5280\/1565\/files\/5bf9dee1cffb5d70d6fcb820d205f794.jpg?v=1736330643"},{"product_id":"zwo-ff107-ff130-apo-0-7-universal-reducer","title":"ZWO FF107\/FF130 APO 0.7× Universal Reducer","description":"\u003cul class=\"DAV-feature-list\"\u003e\n\u003cli\u003e0.7x Focal Reduction Factor\u003c\/li\u003e\n\u003cli\u003eDesigned for ZWO FF107 \u0026amp; FF130 APO Refractors\u003c\/li\u003e\n\u003cli\u003eTriplet Optical Design with 1 ED Element\u003c\/li\u003e\n\u003cli\u003eStandard 55mm Back Focus\u003c\/li\u003e\n\u003cli\u003eIncludes M68, M54, and M48 Adapters\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 0.7x Full-Frame Reducer for FF107-APO and FF130-APO Refractors\u003c\/h2\u003e\n\u003cp\u003eThe ZWO 0.7x Full-Frame Reducer is engineered specifically for the FF107-APO and FF130-APO refractors, transforming them into faster, wider imaging systems. Its triplet optical design uses one ED element to maintain sharp stars across the field, while the standard 55mm back focus and included M48, M54, and M68 adapters ensure compatibility with your existing imaging train.\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\u003e0.7x Reduction for Faster, Wider Imaging\u003c\/h3\u003e\n\u003cp\u003eBy reducing the effective focal length of your FF107-APO or FF130-APO by a factor of 0.7x, this accessory significantly expands your field of view. This allows you to frame large targets like the Andromeda Galaxy (M31) or the North America Nebula (NGC 7000) in a single exposure. The resulting faster focal ratio means you gather the same amount of signal in roughly half the time, reducing demands on your mount's tracking and minimizing frames lost to weather.\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\u003eTriplet ED Optics for Full-Frame Correction in a 3\" Barrel\u003c\/h3\u003e\n\u003cp\u003eThis is not a generic reducer. The 3-element optical design incorporates one ED (Extra-Low Dispersion) glass element to suppress chromatic aberration and ensure sharp, high-contrast stars from the center to the edge of a full-frame sensor. It is optically matched to the FF107 and FF130 refractors to preserve the apochromatic performance of the main objective lenses, delivering a flat, well-corrected field.\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\u003eStandard 55mm Back Focus with M48, M54 \u0026amp; M68 Adapters\u003c\/h3\u003e\n\u003cp\u003eIntegrating the reducer into your imaging train is straightforward. It is designed for a standard 55mm back focus distance, the industry default for most cooled astronomy cameras, filter wheels, and off-axis guiders. To ensure broad compatibility, ZWO includes M68, M54, and M48 adapters, giving you the flexibility to connect to virtually any camera or accessory without sourcing additional parts.\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\"\u003eHow does the ZWO 0.7x reducer change imaging with my FF107 APO?\u003c\/h3\u003e\n\u003c\/div\u003e\n\u003cdiv class=\"DAV-accordion-A\"\u003e\n\u003cp\u003eThe 0.7x reducer makes your FF107 APO a faster and wider instrument. You'll be able to fit larger deep-sky objects, like the entire Veil Nebula complex, into the frame. Because it also reduces exposure times, you can complete projects more quickly or capture fainter details in the same amount of time.\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 ZWO 0.7x reducer for imaging the Andromeda Galaxy (M31) with an FF130 APO?\u003c\/h3\u003e\n\u003c\/div\u003e\n\u003cdiv class=\"DAV-accordion-A\"\u003e\n\u003cp\u003eAt its native focal length, the FF130 APO is too magnified to capture the full extent of the Andromeda Galaxy (M31) with a large-format sensor. The 0.7x reducer widens the field of view enough to frame the galaxy and its companions, M32 and M110, comfortably in a single shot.\u003c\/p\u003e\n\u003c\/div\u003e\n\u003cdiv class=\"DAV-accordion\"\u003e\n\u003ch3 class=\"DAV-accordion-Q\"\u003eIs the ZWO F107130RE reducer compatible with other telescopes?\u003c\/h3\u003e\n\u003c\/div\u003e\n\u003cdiv class=\"DAV-accordion-A\"\u003e\n\u003cp\u003eNo, this reducer is specifically designed and optically matched for the ZWO FF107-APO and ZWO FF130-APO refractors. Using it with other telescopes will likely result in poor optical performance, such as field curvature and elongated stars at the edges of the frame.\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 achieve the 55mm back focus?\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 measured from the rear flange of the reducer's M48 adapter to your camera sensor. Most dedicated astronomy cameras have a native back focus of 17.5mm. You would typically use a combination of standard M48 spacers (not included) to make up the remaining 37.5mm distance. Always check your camera's documentation for its specific back focus measurement.\u003c\/p\u003e\n\u003c\/div\u003e\n\u003cdiv class=\"DAV-accordion\"\u003e\n\u003ch3 class=\"DAV-accordion-Q\"\u003eDoes the triplet design of the ZWO 0.7x reducer correct for field curvature?\u003c\/h3\u003e\n\u003c\/div\u003e\n\u003cdiv class=\"DAV-accordion-A\"\u003e\n\u003cp\u003eYes. The reducer functions as both a focal reducer and a field flattener. Its triplet optical design is optimized to deliver a flat, sharp field across a full-frame sensor when used with the FF107 and FF130 telescopes, which already have a flat-field design.\u003c\/p\u003e\n\u003c\/div\u003e\n\u003cdiv class=\"DAV-accordion\"\u003e\n\u003ch3 class=\"DAV-accordion-Q\"\u003eWhat do the included M68, M54, and M48 adapters for the ZWO reducer do?\u003c\/h3\u003e\n\u003c\/div\u003e\n\u003cdiv class=\"DAV-accordion-A\"\u003e\n\u003cp\u003eThese adapters provide connection flexibility. The reducer itself has a native M68 thread. The included adapters allow you to step down the connection to M54 or the more common M48 (2-inch filter) thread standard, ensuring you can connect it to a wide variety of focusers, rotators, and camera systems.\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-F107130RE\u003c\/td\u003e\n\u003c\/tr\u003e\n\u003ctr\u003e\n\u003ctd\u003eType\u003c\/td\u003e\n\u003ctd\u003eReducer \/ Flattener\u003c\/td\u003e\n\u003c\/tr\u003e\n\u003ctr\u003e\n\u003ctd\u003eReduction Factor\u003c\/td\u003e\n\u003ctd\u003e0.7x\u003c\/td\u003e\n\u003c\/tr\u003e\n\u003ctr\u003e\n\u003ctd\u003eOptical Design\u003c\/td\u003e\n\u003ctd\u003eTriplet (3-element) with 1 ED element\u003c\/td\u003e\n\u003c\/tr\u003e\n\u003ctr\u003e\n\u003ctd\u003eBack Focus\u003c\/td\u003e\n\u003ctd\u003e55 mm\u003c\/td\u003e\n\u003c\/tr\u003e\n\u003ctr\u003e\n\u003ctd\u003eIncluded Adapters\u003c\/td\u003e\n\u003ctd\u003eM68, M54, M48\u003c\/td\u003e\n\u003c\/tr\u003e\n\u003ctr\u003e\n\u003ctd\u003eCompatible Telescopes\u003c\/td\u003e\n\u003ctd\u003eZWO FF107-APO, ZWO FF130-APO\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\"\u003e0.7x Full-Frame Reducer\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\"\u003eM68 Adapter\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\"\u003eM54 Adapter\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\"\u003eM48 Adapter\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 Limited Warranty\u003c\/a\u003e\u003c\/li\u003e\n\u003c\/ul\u003e","brand":"ZWO","offers":[{"title":"Default Title","offer_id":49552544596253,"sku":"ZWO-F107130RE","price":433.0,"currency_code":"CAD","in_stock":false}],"thumbnail_url":"\/\/cdn.shopify.com\/s\/files\/1\/0753\/5280\/1565\/files\/4ea38edd3051cf3e39d3a88b8abd6fcd.jpg?v=1736331163"},{"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\u003e6.61 lb. Weight with Handle, Rings and Dovetail\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 6.61 lbs. with rings and dovetail, 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 air-spaced quadruplet 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 over 3 lbs. more and requires a more substantial mount. The FF70's primary advantage is its compact, 6.61 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\u003e6.61 lb. Package for Grab-and-Go Astrophotography\u003c\/h3\u003e\n\u003cp\u003eAt only 6.61 lbs. with rings and dovetail, the FF70 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 air-spaced quadruplet 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 6.61 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 6.61 lb. weight (with rings and dovetail) 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 6.61 lbs. (compared to the FF90's 9.97 lbs.), both with rings and dovetail, 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\u003e5.51 lbs. (6.61 lbs. with handle, rings and dovetail)\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":849.0,"currency_code":"CAD","in_stock":true}],"thumbnail_url":"\/\/cdn.shopify.com\/s\/files\/1\/0753\/5280\/1565\/files\/ZWO-FF70-APO-Quadruplet-Refractor-1.jpg?v=1781058373"},{"product_id":"zwo-ff90-apo-90mm-quadruplet-refractor","title":"ZWO FF90-APO 90mm Quadruplet Refractor F\/6.8","description":"\u003cul class=\"DAV-feature-list\"\u003e\n\u003cli\u003e90mm Aperture\u003c\/li\u003e\n\u003cli\u003e609mm Focal Length (f\/6.8)\u003c\/li\u003e\n\u003cli\u003e4-Element Quadruplet Optical Design\u003c\/li\u003e\n\u003cli\u003e3\" Dual-Speed Rack \u0026amp; Pinion Focuser\u003c\/li\u003e\n\u003cli\u003e9.97 lb. Weight with Handle, Rings and Dovetail\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 FF90-APO 90mm Quadruplet Refractor F\/6.8\u003c\/h2\u003e\n\u003cp\u003eThe ZWO FF90-APO refractor integrates a 90mm objective and a 609mm focal length into a self-flattening optical design for wide-field astrophotography. Its 4-element quadruplet lens system corrects for field curvature across a full-frame sensor without requiring a separate flattener, and the 9.97 lb. package (with handle, rings and dovetail) is managed by a rigid 3\" dual-speed focuser.\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\u003eSelf-Flattening 4-Element Optics at f\/6.8\u003c\/h3\u003e\n\u003cp\u003eThe core of the FF90 is its 4-element air-spaced quadruplet optical design, which provides a flat, corrected field of view without the need for additional accessories or complex back-focus calculations. This simplifies your imaging train significantly; as long as you can reach focus, the star field will be sharp edge-to-edge. At a focal ratio of f\/6.8, you acquire deep signal on targets like the Eagle Nebula (M16) or the Triangulum Galaxy (M33) with shorter sub-exposure times than a slower instrument would require.\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\u003e3-inch Focuser for a 9.97 lb. Package\u003c\/h3\u003e\n\u003cp\u003eTo prevent flexure with modern imaging cameras and filter wheels, the FF90 is equipped with a 3\" rack \u0026amp; pinion focuser. This large-format focuser provides a rigid, stable platform for your equipment, while the 10:1 dual-speed mechanism allows for the fine adjustments necessary to achieve critical focus. The telescope weighs 9.97 lb. with handle, rings and dovetail, making it a stable and manageable payload for a wide range of mid-sized equatorial mounts.\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 FF90 vs. ZWO FF70: Aperture and Image Scale\u003c\/h3\u003e\n\u003cp\u003eWhen choosing between ZWO's quadruplet refractors, the primary difference is light-gathering ability and image scale. The FF70 is lighter and offers a wider true field of view, making it ideal for the largest nebulae. The FF90, however, has a distinct advantage in light grasp and resolution with its 90mm aperture. Its 609mm focal length also provides greater magnification, framing smaller deep-sky objects more effectively than the shorter focal length FF70. The trade-off is weight; the FF90 weighs 9.97 lb., requiring a more substantial mount than the 6.61 lb. FF70.\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 FF90 APO?\u003c\/h3\u003e\n\u003c\/div\u003e\n\u003cdiv class=\"DAV-accordion-A\"\u003e\n\u003cp\u003eNo. The ZWO FF90 APO uses a \u003cstrong\u003e4-element quadruplet\u003c\/strong\u003e optical design that is \"self-flattening.\" This means you do not need to purchase a separate field flattener or calculate a precise back-focus distance. Simply attach your camera and focus.\u003c\/p\u003e\n\u003c\/div\u003e\n\u003cdiv class=\"DAV-accordion\"\u003e\n\u003ch3 class=\"DAV-accordion-Q\"\u003eWhat kind of mount is required for the 9.97 lb. ZWO FF90 APO?\u003c\/h3\u003e\n\u003c\/div\u003e\n\u003cdiv class=\"DAV-accordion-A\"\u003e\n\u003cp\u003eFor astrophotography, a mount should typically carry no more than 50-60% of its maximum rated payload capacity. With a weight of \u003cstrong\u003e9.97 lb.\u003c\/strong\u003e (with handle, rings and dovetail), plus the weight of your camera and guide scope, a mount in the 25-30 lb payload class (like a Celestron AVX, Sky-Watcher HEQ5, or ZWO AM3) would be a stable platform.\u003c\/p\u003e\n\u003c\/div\u003e\n\u003cdiv class=\"DAV-accordion\"\u003e\n\u003ch3 class=\"DAV-accordion-Q\"\u003eHow does the ZWO FF90 APO perform on the Triangulum Galaxy (M33)?\u003c\/h3\u003e\n\u003c\/div\u003e\n\u003cdiv class=\"DAV-accordion-A\"\u003e\n\u003cp\u003eThe ZWO FF90's \u003cstrong\u003e609mm focal length\u003c\/strong\u003e is an excellent match for medium-to-large galaxies like M33. Paired with a full-frame or APS-C sensor, it will frame the entire galaxy and its spiral arms with room to spare, while the \u003cstrong\u003e90mm aperture\u003c\/strong\u003e is sufficient to resolve its brighter HII regions and star-forming areas.\u003c\/p\u003e\n\u003c\/div\u003e\n\u003cdiv class=\"DAV-accordion\"\u003e\n\u003ch3 class=\"DAV-accordion-Q\"\u003eWhat adapters are needed to connect a full-frame camera to the ZWO FF90?\u003c\/h3\u003e\n\u003c\/div\u003e\n\u003cdiv class=\"DAV-accordion-A\"\u003e\n\u003cp\u003eThe ZWO FF90 includes a photography extension tube with standard M54 and M48 male threads, which are common connection sizes for full-frame cameras and filter wheels. You will likely only need a standard M48 T-ring for your specific camera brand (e.g., Canon, Nikon, Sony) to connect directly.\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 ZWO FF90's 4-element design over a standard doublet?\u003c\/h3\u003e\n\u003c\/div\u003e\n\u003cdiv class=\"DAV-accordion-A\"\u003e\n\u003cp\u003eA standard doublet refractor requires a separate field flattener accessory to correct for field curvature, which introduces potential spacing errors and extra cost. The ZWO FF90's integrated \u003cstrong\u003e4-element\u003c\/strong\u003e system corrects for chromatic aberration and field curvature simultaneously, resulting in a simpler, more rigid imaging train with sharp stars across the entire frame by design.\u003c\/p\u003e\n\u003c\/div\u003e\n\u003cdiv class=\"DAV-accordion\"\u003e\n\u003ch3 class=\"DAV-accordion-Q\"\u003eIs the ZWO FF90 APO suitable for visual astronomy?\u003c\/h3\u003e\n\u003c\/div\u003e\n\u003cdiv class=\"DAV-accordion-A\"\u003e\n\u003cp\u003eYes. While designed for imaging, the FF90 is also an excellent visual instrument. Its \u003cstrong\u003e90mm aperture\u003c\/strong\u003e and apochromatic optics provide high-contrast, color-free views of the Moon, planets, and bright deep-sky objects. You will need a 2\" or 1.25\" star diagonal and eyepieces, which are not included.\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-FF90-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\u003e90mm (3.54\")\u003c\/td\u003e\n\u003c\/tr\u003e\n\u003ctr\u003e\n\u003ctd\u003eFocal Length\u003c\/td\u003e\n\u003ctd\u003e609 mm\u003c\/td\u003e\n\u003c\/tr\u003e\n\u003ctr\u003e\n\u003ctd\u003eFocal Ratio\u003c\/td\u003e\n\u003ctd\u003ef\/6.8\u003c\/td\u003e\n\u003c\/tr\u003e\n\u003ctr\u003e\n\u003ctd\u003eFocuser\u003c\/td\u003e\n\u003ctd\u003e3\" Rack \u0026amp; Pinion\u003c\/td\u003e\n\u003c\/tr\u003e\n\u003ctr\u003e\n\u003ctd\u003eFocuser Speed\u003c\/td\u003e\n\u003ctd\u003eDual Speed\u003c\/td\u003e\n\u003c\/tr\u003e\n\u003ctr\u003e\n\u003ctd\u003eOTA Weight\u003c\/td\u003e\n\u003ctd\u003e8.64 lb. (9.97 lb. with handle, rings and dovetail)\u003c\/td\u003e\n\u003c\/tr\u003e\n\u003ctr\u003e\n\u003ctd\u003eSeries\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 90 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\"\u003eVixen 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\n\u003ca href=\"https:\/\/davidastro.com\/pages\/zwo-warranty-policy\" rel=\"noopener\" target=\"_blank\"\u003eZWO 2-Year Limited Warranty\u003c\/a\u003e\n\u003c\/li\u003e\n\u003c\/ul\u003e","brand":"ZWO","offers":[{"title":"Default Title","offer_id":51858442977565,"sku":"ZWO-FF90-APO","price":1409.0,"currency_code":"CAD","in_stock":true}],"thumbnail_url":"\/\/cdn.shopify.com\/s\/files\/1\/0753\/5280\/1565\/files\/ZWO-FF90-APO-Quadruplet-Refractor-1.jpg?v=1781058596"},{"product_id":"zwo-ff110-apo-110mm-quadruplet-refractor","title":"ZWO FF110-APO 110mm Quadruplet Refractor F\/7.0","description":"\u003cul class=\"DAV-feature-list\"\u003e\n\u003cli\u003e110mm Aperture\u003c\/li\u003e\n\u003cli\u003e766mm Focal Length (f\/7)\u003c\/li\u003e\n\u003cli\u003e4-Element Apochromatic Optics\u003c\/li\u003e\n\u003cli\u003eIntegrated Field Flattener\u003c\/li\u003e\n\u003cli\u003e3-inch Dual-Speed Focuser\u003c\/li\u003e\n\u003cli\u003e14.9 lb. Weight with Handle, Rings and Dovetail\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 FF110-APO 110mm Quadruplet Refractor F\/7.0\u003c\/h2\u003e\n\u003cp\u003eThe ZWO FF110-APO combines a 4-element optical system with a 766mm focal length (f\/7) to deliver a fully corrected image field without external flatteners. Its 110mm aperture gathers significant light for detailed deep-sky imaging, while the heavy-duty 3-inch rack-and-pinion focuser supports large camera packages without flexure. The telescope weighs 14.9 lb with handle, rings and dovetail, requiring a stable equatorial mount for precise tracking.\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\u003eFlat-Field 4-Element Optics at f\/7\u003c\/h3\u003e\n\u003cp\u003eThis refractor's quadruplet optical design provides apochromatic color correction and a natively flat field, eliminating the need for a separate flattener. This simplifies your imaging train and removes the complexity of calculating back focus; as long as you can achieve focus, the starfield is sharp edge-to-edge. The 766mm focal length frames many popular deep-sky targets like the Horsehead Nebula (Barnard 33) and the core of the Andromeda Galaxy (M31) with room to spare on full-frame sensors.\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 3-inch Dual-Speed Focuser\u003c\/h3\u003e\n\u003cp\u003eTo prevent image shift and flexure with heavy cameras and filter wheels, the FF110-APO is built with a robust 3-inch rack-and-pinion focuser. The dual-speed 1:10 fine adjustment knob allows you to achieve critical focus with precision, which is essential for resolving fine detail. This large-format focuser ensures the optical path is never vignetted, even with large full-frame camera sensors.\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 FF110-APO vs. ZWO FF90-APO\u003c\/h3\u003e\n\u003cp\u003eThe primary distinction between the ZWO FF110-APO and its smaller sibling is between image scale and portability.\u003c\/p\u003e\n\u003cul\u003e\n\u003cli\u003e\n\u003cstrong\u003eZWO FF90-APO Advantage:\u003c\/strong\u003e At 9.97 lb, the FF90 is substantially lighter than the 14.9 lb FF110-APO, allowing it to be used on smaller, more portable equatorial mounts.\u003c\/li\u003e\n\u003cli\u003e\n\u003cstrong\u003eZWO FF110-APO Advantage:\u003c\/strong\u003e The FF110-APO's 766mm focal length produces a larger image scale than the FF90's 609mm. This allows you to resolve more detail on smaller galaxies and planetary nebulae with the same camera sensor.\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\u003eImaging-Ready at 14.9 lb\u003c\/h3\u003e\n\u003cp\u003eThe FF110-APO includes essential hardware to get you mounted and imaging quickly, including a set of mounting rings and a standard Vixen-style dovetail plate. A key trade-off for its optical power is the 14.9 lb weight with handle, rings and dovetail. This requires an equatorial mount in the EQ6\/CEM40 class or greater to ensure stable, unguided exposures and reliable tracking for long-exposure astrophotography.\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\"\u003eIs the ZWO FF110-APO a good choice for imaging the Horsehead Nebula (Barnard 33)?\u003c\/h3\u003e\n\u003c\/div\u003e\n\u003cdiv class=\"DAV-accordion-A\"\u003e\n\u003cp\u003eYes. With its 766mm focal length, the ZWO FF110-APO provides an excellent image scale for framing the Horsehead and Flame Nebula region, especially when paired with an APS-C or full-frame sensor. The flat-field optics will ensure that the prominent stars in the field, like Alnitak, remain sharp without needing a separate corrector.\u003c\/p\u003e\n\u003c\/div\u003e\n\u003cdiv class=\"DAV-accordion\"\u003e\n\u003ch3 class=\"DAV-accordion-Q\"\u003eWhat kind of mount is needed for the ZWO FF110-APO's 14.9 lb weight?\u003c\/h3\u003e\n\u003c\/div\u003e\n\u003cdiv class=\"DAV-accordion-A\"\u003e\n\u003cp\u003eFor stable imaging, a mount with a payload capacity of at least 25-30 pounds is recommended to handle the 14.9 lb telescope (with handle, rings and dovetail) plus the weight of your camera, guidescope, and other accessories. Mounts like the Sky-Watcher EQ6-R Pro or ZWO's own AM5 are appropriate choices.\u003c\/p\u003e\n\u003c\/div\u003e\n\u003cdiv class=\"DAV-accordion\"\u003e\n\u003ch3 class=\"DAV-accordion-Q\"\u003eDo I need a separate field flattener for the ZWO FF110-APO?\u003c\/h3\u003e\n\u003c\/div\u003e\n\u003cdiv class=\"DAV-accordion-A\"\u003e\n\u003cp\u003eNo. The ZWO FF110-APO uses a 4-element air-spaced quadruplet optical design that has an integrated flattener. You do not need to purchase an additional flattener or calculate a specific back-focus distance, which simplifies the imaging setup significantly.\u003c\/p\u003e\n\u003c\/div\u003e\n\u003cdiv class=\"DAV-accordion\"\u003e\n\u003ch3 class=\"DAV-accordion-Q\"\u003eHow do I attach a full-frame camera to the ZWO FF110-APO?\u003c\/h3\u003e\n\u003c\/div\u003e\n\u003cdiv class=\"DAV-accordion-A\"\u003e\n\u003cp\u003eThe telescope includes a photography extension tube that provides standard M48x0.75 and M54x0.75 male threads. You connect your camera using the appropriate T-ring and adapters for your specific camera model to attach to these threads.\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 3-inch focuser on the ZWO FF110-APO?\u003c\/h3\u003e\n\u003c\/div\u003e\n\u003cdiv class=\"DAV-accordion-A\"\u003e\n\u003cp\u003eA 3-inch focuser provides two main benefits. First, its larger diameter prevents vignetting (darkening of the corners) on large, full-frame sensors. Second, its robust rack-and-pinion design provides higher load capacity, preventing sag or flex when using heavy imaging equipment like cooled cameras and filter wheels.\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 Number\u003c\/td\u003e\n\u003ctd\u003eZWO-FF110-APO\u003c\/td\u003e\n\u003c\/tr\u003e\n\u003ctr\u003e\n\u003ctd\u003eModel\u003c\/td\u003e\n\u003ctd\u003e110 mm APO Refractor\u003c\/td\u003e\n\u003c\/tr\u003e\n\u003ctr\u003e\n\u003ctd\u003eSeries\u003c\/td\u003e\n\u003ctd\u003eZWO Refractors\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\u003e110mm (4.33\")\u003c\/td\u003e\n\u003c\/tr\u003e\n\u003ctr\u003e\n\u003ctd\u003eFocal Length\u003c\/td\u003e\n\u003ctd\u003e766 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\u003e3\" Dual-Speed Rack \u0026amp; Pinion\u003c\/td\u003e\n\u003c\/tr\u003e\n\u003ctr\u003e\n\u003ctd\u003eOTA Weight\u003c\/td\u003e\n\u003ctd\u003e12.65 lb. (14.9 lb. with handle, rings and dovetail)\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 110 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× 1 Set\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\"\u003eVixen 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\n\u003ca href=\"https:\/\/davidastro.com\/pages\/zwo-warranty-policy\" rel=\"noopener\" target=\"_blank\"\u003eZWO 2-Year Warranty\u003c\/a\u003e\n\u003c\/li\u003e\n\u003c\/ul\u003e","brand":"ZWO","offers":[{"title":"Default Title","offer_id":51858476531997,"sku":"ZWO-FF110-APO","price":2109.0,"currency_code":"CAD","in_stock":true}],"thumbnail_url":"\/\/cdn.shopify.com\/s\/files\/1\/0753\/5280\/1565\/files\/ZWO-FF110-APO-Quadruplet-Refractor-1.jpg?v=1781058773"},{"product_id":"zwo-ff131-apo-131mm-quadruplet-refractor","title":"ZWO FF131-APO 131mm Quadruplet Refractor F\/7.5","description":"\u003cul class=\"DAV-feature-list\"\u003e\n\u003cli\u003e131mm Aperture\u003c\/li\u003e\n\u003cli\u003e983mm Focal Length (f\/7.5)\u003c\/li\u003e\n\u003cli\u003e4-Element Air-Spaced Quadruplet Design\u003c\/li\u003e\n\u003cli\u003e3-inch Dual-Speed Rack \u0026amp; Pinion Focuser\u003c\/li\u003e\n\u003cli\u003e20.7 lb. Weight with Handle, Rings and Dovetail\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 FF131-APO 131mm Quadruplet Refractor F\/7.5\u003c\/h2\u003e\n\u003cp\u003eThe ZWO FF131-APO's 131mm (5.15\") aperture and 983mm focal length are built on a 4-element optical design for high-contrast imaging of demanding deep-sky targets. This f\/7.5 system features a rigid 3\" dual-speed focuser and weighs 20.7 lbs, providing a stable platform for full-frame cameras without requiring additional field flatteners.\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\u003eFlat-Field Quadruplet Optics at 983mm\u003c\/h3\u003e\n\u003cp\u003eThe 4-element air-spaced quadruplet design delivers a corrected image circle without the need for an external flattener or complex back-focus calculations. This simplifies your imaging train, allowing you to attach a camera and achieve sharp stars across the entire field, as long as the focuser can reach its target. The 983mm focal length provides the ideal image scale for resolving details in smaller targets like the Whirlpool Galaxy (M51) or the Dumbbell Nebula (M27) with modern CMOS sensors.\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\u003e3-inch Rack \u0026amp; Pinion Focuser\u003c\/h3\u003e\n\u003cp\u003eTo support heavy imaging loads, the FF131-APO is equipped with a 3\" rack and pinion focuser. Its large diameter prevents vignetting on full-frame sensors and provides the rigidity needed to hold a filter wheel and camera without flexure. The dual-speed mechanism allows for coarse adjustments to find the general focus point, followed by fine 1:10 adjustments to achieve critical sharpness.\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 FF131-APO vs. the 110mm FF110-APO\u003c\/h3\u003e\n\u003cp\u003eThe primary advantage of the smaller FF110-APO is its lower weight (14.9 lbs), making it compatible with lighter-duty mounts. The FF131-APO, at 20.7 lbs, requires a more substantial mount but delivers significantly more light-gathering power and resolution from its 131mm aperture. Its 983mm focal length also yields a tighter image scale than the FF110's 766mm, resolving finer details on distant galaxies and nebulae.\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 Design at 20.7 lbs\u003c\/h3\u003e\n\u003cp\u003eThe FF131-APO's 20.7 lb. weight (with handle, rings and dovetail) is a key factor in mount selection, requiring a platform in the EQ6-R, AM5, or a higher payload class for stable, unguided imaging. ZWO includes essential mounting hardware right in the box to integrate the OTA into your setup. The package contains a set of mounting rings, a Vixen-style dovetail plate, and two findershoes, providing attachment points for guide scopes, finder scopes, or an ASIAIR controller.\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 FF131-APO?\u003c\/h3\u003e\n\u003c\/div\u003e\n\u003cdiv class=\"DAV-accordion-A\"\u003e\n\u003cp\u003eNo. The ZWO FF131-APO uses a 4-element air-spaced quadruplet design that has a built-in flattener. You do not need to purchase an additional flattener or calculate any back-focus spacing; as long as you can reach focus, the field will be flat.\u003c\/p\u003e\n\u003c\/div\u003e\n\u003cdiv class=\"DAV-accordion\"\u003e\n\u003ch3 class=\"DAV-accordion-Q\"\u003eWhat kind of mount is required for the 20.7 lb ZWO FF131-APO?\u003c\/h3\u003e\n\u003c\/div\u003e\n\u003cdiv class=\"DAV-accordion-A\"\u003e\n\u003cp\u003eDue to its 20.7 lb. weight, the ZWO FF131-APO requires a medium to heavy-duty equatorial mount for astrophotography. For reliable tracking, a mount with a payload capacity of at least 35-40 lbs is recommended, such as a Sky-Watcher EQ6-R Pro, ZWO AM5, or a larger class of mount.\u003c\/p\u003e\n\u003c\/div\u003e\n\u003cdiv class=\"DAV-accordion\"\u003e\n\u003ch3 class=\"DAV-accordion-Q\"\u003eHow does the FF131-APO's 983mm focal length perform on targets like the Whirlpool Galaxy (M51)?\u003c\/h3\u003e\n\u003c\/div\u003e\n\u003cdiv class=\"DAV-accordion-A\"\u003e\n\u003cp\u003eThe 983mm focal length is excellent for medium-to-small deep-sky objects. On a target like the Whirlpool Galaxy (M51), it provides enough image scale to resolve individual dust lanes and star-forming regions, especially when paired with cameras that have small pixels (under 4µm).\u003c\/p\u003e\n\u003c\/div\u003e\n\u003cdiv class=\"DAV-accordion\"\u003e\n\u003ch3 class=\"DAV-accordion-Q\"\u003eIs the ZWO FF131-APO a good choice for a portable setup?\u003c\/h3\u003e\n\u003c\/div\u003e\n\u003cdiv class=\"DAV-accordion-A\"\u003e\n\u003cp\u003eAt 20.7 lbs with its handle, rings and dovetail, plus the required heavy-duty mount, the ZWO FF131-APO is generally considered a backyard or observatory-class instrument rather than a \"grab-and-go\" portable setup. While transportable, it requires more effort to set up than smaller refractors.\u003c\/p\u003e\n\u003c\/div\u003e\n\u003cdiv class=\"DAV-accordion\"\u003e\n\u003ch3 class=\"DAV-accordion-Q\"\u003eHow does the ZWO FF131-APO compare to the smaller FF110-APO?\u003c\/h3\u003e\n\u003c\/div\u003e\n\u003cdiv class=\"DAV-accordion-A\"\u003e\n\u003cp\u003eThe FF131-APO offers a 20% increase in aperture over the 110mm model, resulting in higher resolution and the ability to capture fainter detail. It also has a longer focal length (983mm vs. 766mm), making it better suited for smaller targets. The main trade-off is weight; the FF131-APO is nearly 6 lbs heavier and requires a more robust mount.\u003c\/p\u003e\n\u003c\/div\u003e\n\u003cdiv class=\"DAV-accordion\"\u003e\n\u003ch3 class=\"DAV-accordion-Q\"\u003eHow do I attach a full-frame camera to the FF131-APO's 3\" focuser?\u003c\/h3\u003e\n\u003c\/div\u003e\n\u003cdiv class=\"DAV-accordion-A\"\u003e\n\u003cp\u003eThe ZWO FF131-APO includes a photography extension tube with standard M48x0.75 and M54x0.75 male threads. You connect this to the focuser's drawtube, and then attach your camera using the appropriate T-ring or adapter for your camera's bayonet or thread size.\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-FF131-APO\u003c\/td\u003e\n\u003c\/tr\u003e\n\u003ctr\u003e\n\u003ctd\u003eModel\u003c\/td\u003e\n\u003ctd\u003e131 mm APO Refractor\u003c\/td\u003e\n\u003c\/tr\u003e\n\u003ctr\u003e\n\u003ctd\u003eSeries\u003c\/td\u003e\n\u003ctd\u003eZWO Refractors\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\u003eAperture\u003c\/td\u003e\n\u003ctd\u003e131mm (5.15\")\u003c\/td\u003e\n\u003c\/tr\u003e\n\u003ctr\u003e\n\u003ctd\u003eFocal Length\u003c\/td\u003e\n\u003ctd\u003e983 mm\u003c\/td\u003e\n\u003c\/tr\u003e\n\u003ctr\u003e\n\u003ctd\u003eFocal Ratio\u003c\/td\u003e\n\u003ctd\u003ef\/7.5\u003c\/td\u003e\n\u003c\/tr\u003e\n\u003ctr\u003e\n\u003ctd\u003eOptical Elements\u003c\/td\u003e\n\u003ctd\u003e4 (Quadruplet)\u003c\/td\u003e\n\u003c\/tr\u003e\n\u003ctr\u003e\n\u003ctd\u003eFocuser\u003c\/td\u003e\n\u003ctd\u003e3\" Rack \u0026amp; Pinion\u003c\/td\u003e\n\u003c\/tr\u003e\n\u003ctr\u003e\n\u003ctd\u003eFocuser Speed\u003c\/td\u003e\n\u003ctd\u003eDual Speed\u003c\/td\u003e\n\u003c\/tr\u003e\n\u003ctr\u003e\n\u003ctd\u003eOTA Weight\u003c\/td\u003e\n\u003ctd\u003e17.42 lb. (20.72 lb. with handle, rings and dovetail)\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\u003eNone\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 131 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× 1 Pair\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\"\u003eVixen 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 ZWO 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":51858498519325,"sku":"ZWO-FF131-APO","price":2819.0,"currency_code":"CAD","in_stock":true}],"thumbnail_url":"\/\/cdn.shopify.com\/s\/files\/1\/0753\/5280\/1565\/files\/ZWO-FF131-APO-Quadruplet-Refractor-1.jpg?v=1781058960"}],"url":"https:\/\/davidastro.com\/collections\/zwo-ff-apochromatic-refractors.oembed","provider":"David Astro","version":"1.0","type":"link"}