{"product_id":"svbony-sv209-1-0x-field-flattener-for-sv550-80f6","title":"SVBONY SV209 1.0X Field Flattener for SV550 80F6","description":"\u003cul class=\"DAV-feature-list\"\u003e\n\u003cli\u003e1.0x focal correction factor\u003c\/li\u003e\n\u003cli\u003eDesigned for the Svbony SV550 80F6 telescope\u003c\/li\u003e\n\u003cli\u003e45mm fully illuminated image circle\u003c\/li\u003e\n\u003cli\u003eM63x1 telescope-side connection\u003c\/li\u003e\n\u003cli\u003eProvides 55mm, 91.5mm, and 103mm back focus distances\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\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\u003eSvbony SV209 1.0x Flattener for SV550 80F6\u003c\/h2\u003e\n\u003cp\u003eThe Svbony SV209 1.0x Flattener is engineered specifically for the SV550 80F6 refractor, using a 2-element optical design to produce a 45mm fully illuminated field for full-frame sensors. It connects directly to the telescope's drawtube via an M63x1 male thread and provides multiple back focus options, including the standard 55mm distance via an M48x0.75 camera connection. This flattener maintains your telescope's native focal length with its 1.0x factor, ensuring pinpoint stars across the entire image frame without altering the field of view.\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\u003e1.0x Flat-Field Correction for the SV550 80F6\u003c\/h3\u003e\n\u003cp\u003eRefractor telescopes naturally exhibit field curvature, causing stars at the edge of an image to appear elongated or out of focus. The SV209 is optically matched to the SV550 80F6 to counteract this distortion. Its 2-element, fully multi-coated (FMC) lens system corrects for off-axis aberrations without changing the telescope's focal length, preserving the original 1.0x magnification and f-ratio.\u003c\/p\u003e\n\u003cp\u003eThis dedicated design ensures that the correction is optimized for the SV550's optical system, delivering sharp, round stars from the center to the corners of your sensor. This is a critical upgrade for astrophotography, transforming the SV550 into a flat-field imaging instrument capable of capturing clean, wide-field vistas of nebulae and star clusters.\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\u003eM63x1 Connection and Multiple Back Focus Options\u003c\/h3\u003e\n\u003cp\u003eThe SV209 establishes a secure, threaded connection by attaching directly to the SV550's M63x1 drawtube threads, eliminating any potential for flexure that can occur with 2-inch compression fittings. The camera side offers multiple documented back focus distances—103mm from the female M63x1 thread, and either 55mm or 91.5mm from the male M48x0.75 thread—to accommodate various imaging train components like off-axis guiders and filter wheels.\u003c\/p\u003e\n\u003cul\u003e\n\u003cli\u003e\n\u003cstrong\u003eStandard 55mm Back Focus:\u003c\/strong\u003e The M48x0.75 thread is configured to achieve the 55mm back focus standard used by most DSLRs, mirrorless cameras with T-rings, and dedicated astronomy cameras.\u003c\/li\u003e\n\u003cli\u003e\n\u003cstrong\u003eIntegrated Filter Threads:\u003c\/strong\u003e The design incorporates threads for standard 2-inch (M48) astronomy filters, allowing you to easily add light pollution or narrowband filters into your optical path without needing a separate filter drawer.\u003c\/li\u003e\n\u003cli\u003e\n\u003cstrong\u003eSecure Installation:\u003c\/strong\u003e The flattener threads on after removing the SV550's stock 2-inch eyepiece adapter, creating a rigid imaging train from the focuser to the 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\u003e45mm Image Circle for Full-Frame Sensors\u003c\/h3\u003e\n\u003cp\u003eA key capability of the SV209 is its ability to produce a fully illuminated and corrected image circle of 45mm. This generous field is large enough to cover modern full-frame (36x24mm) camera sensors without vignetting, a significant advantage for capturing large targets like the Andromeda Galaxy (M31) or the North America Nebula (NGC 7000).\u003c\/p\u003e\n\u003cp\u003eWhile many flatteners are designed only for smaller APS-C sensors, the SV209's 45mm corrected field unlocks the full potential of the SV550 80F6 telescope for use with larger sensors. This ensures even illumination and sharp stars across the entire frame, maximizing the data captured in every exposure.\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 is the main purpose of the Svbony SV209 Flattener?\u003c\/h3\u003e\n\u003c\/div\u003e\n\u003cdiv class=\"DAV-accordion-A\"\u003e\n\u003cp\u003eThe Svbony SV209 is an optical corrector designed specifically for the \u003cstrong\u003eSvbony SV550 80F6\u003c\/strong\u003e telescope. Its function is to eliminate the natural field curvature of the telescope's optics, ensuring that stars are sharp and pinpoint across the entire photograph, from the center to the very corners. It does this without changing the telescope's focal length (1.0x factor).\u003c\/p\u003e\n\u003c\/div\u003e\n\u003cdiv class=\"DAV-accordion\"\u003e\n\u003ch3 class=\"DAV-accordion-Q\"\u003eIs the SV209 compatible with telescopes other than the SV550 80F6?\u003c\/h3\u003e\n\u003c\/div\u003e\n\u003cdiv class=\"DAV-accordion-A\"\u003e\n\u003cp\u003eNo, the SV209 is designed as a dedicated flattener for the \u003cstrong\u003eSvbony SV550 80F6\u003c\/strong\u003e. Field flatteners are calculated for a specific optical design, and using this on another telescope, even one with similar specs, will likely result in poor correction. For optimal results, it should only be used with the SV550.\u003c\/p\u003e\n\u003c\/div\u003e\n\u003cdiv class=\"DAV-accordion\"\u003e\n\u003ch3 class=\"DAV-accordion-Q\"\u003eWhat imaging setups are the 55mm, 91.5mm, and 103mm back focus options for on the SV209?\u003c\/h3\u003e\n\u003c\/div\u003e\n\u003cdiv class=\"DAV-accordion-A\"\u003e\n\u003cp\u003eThe different back focus distances allow for flexibility in your imaging train:\u003c\/p\u003e\n\u003cul\u003e\n\u003cli\u003e\n\u003cstrong\u003e55mm (from M48 thread):\u003c\/strong\u003e This is the industry standard for DSLRs\/mirrorless cameras with a T-ring, as well as many dedicated astronomy cameras.\u003c\/li\u003e\n\u003cli\u003e\n\u003cstrong\u003e91.5mm \/ 103mm:\u003c\/strong\u003e These longer distances provide the necessary space to insert additional accessories between the flattener and the camera, such as an off-axis guider (OAG), a filter wheel, or other adapters, while still achieving the correct total spacing for a flat field.\u003c\/li\u003e\n\u003c\/ul\u003e\n\u003c\/div\u003e\n\u003cdiv class=\"DAV-accordion\"\u003e\n\u003ch3 class=\"DAV-accordion-Q\"\u003eCan I use 2-inch filters with the Svbony SV209?\u003c\/h3\u003e\n\u003c\/div\u003e\n\u003cdiv class=\"DAV-accordion-A\"\u003e\n\u003cp\u003eYes. The SV209 includes standard M48x0.75 threads (the same as 2-inch filters) on the camera-side adapter, allowing you to directly attach 2-inch filters for light pollution reduction or narrowband imaging.\u003c\/p\u003e\n\u003c\/div\u003e\n\u003cdiv class=\"DAV-accordion\"\u003e\n\u003ch3 class=\"DAV-accordion-Q\"\u003eWill the SV209 Flattener illuminate my full-frame camera when imaging the Andromeda Galaxy (M31) with the SV550?\u003c\/h3\u003e\n\u003c\/div\u003e\n\u003cdiv class=\"DAV-accordion-A\"\u003e\n\u003cp\u003eYes, absolutely. The SV209 produces a \u003cstrong\u003e45mm fully illuminated and corrected image circle\u003c\/strong\u003e. This is more than large enough to cover a standard full-frame sensor (which has a ~43mm diagonal), ensuring no vignetting and sharp stars across the entire frame when capturing large targets like the Andromeda Galaxy (M31).\u003c\/p\u003e\n\u003c\/div\u003e\n\u003cdiv class=\"DAV-accordion\"\u003e\n\u003ch3 class=\"DAV-accordion-Q\"\u003eHow do I install the Svbony SV209 on my SV550 80F6 telescope?\u003c\/h3\u003e\n\u003c\/div\u003e\n\u003cdiv class=\"DAV-accordion-A\"\u003e\n\u003cp\u003eInstallation requires a direct threaded connection. First, you must unscrew the standard 2-inch eyepiece holder from the focuser drawtube of your SV550. This will expose the male M63x1 threads on the drawtube. The SV209 flattener then threads directly onto this M63x1 connection, providing a secure, flex-free fit.\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\u003eBrand\u003c\/td\u003e\n\u003ctd\u003eSVBONY\u003c\/td\u003e\n\u003c\/tr\u003e\n\u003ctr\u003e\n\u003ctd\u003eApplication\u003c\/td\u003e\n\u003ctd\u003eField Flattener for SV550 80F6\u003c\/td\u003e\n\u003c\/tr\u003e\n\u003ctr\u003e\n\u003ctd\u003eCorrection Factor\u003c\/td\u003e\n\u003ctd\u003e1.0x (no focal length change)\u003c\/td\u003e\n\u003c\/tr\u003e\n\u003ctr\u003e\n\u003ctd\u003eOptical Design\u003c\/td\u003e\n\u003ctd\u003e2 elements\u003c\/td\u003e\n\u003c\/tr\u003e\n\u003ctr\u003e\n\u003ctd\u003eCoatings\u003c\/td\u003e\n\u003ctd\u003eFully Multi-Coated (FMC)\u003c\/td\u003e\n\u003c\/tr\u003e\n\u003ctr\u003e\n\u003ctd\u003eIlluminated Field\u003c\/td\u003e\n\u003ctd\u003e45mm (Supports full-frame sensors)\u003c\/td\u003e\n\u003c\/tr\u003e\n\u003ctr\u003e\n\u003ctd\u003eTelescope Connection\u003c\/td\u003e\n\u003ctd\u003eM63x1 male thread\u003c\/td\u003e\n\u003c\/tr\u003e\n\u003ctr\u003e\n\u003ctd\u003eCamera Connection 1 (Thread)\u003c\/td\u003e\n\u003ctd\u003eM63x1 female thread\u003c\/td\u003e\n\u003c\/tr\u003e\n\u003ctr\u003e\n\u003ctd\u003eCamera Connection 1 (Back Focus)\u003c\/td\u003e\n\u003ctd\u003e103mm\u003c\/td\u003e\n\u003c\/tr\u003e\n\u003ctr\u003e\n\u003ctd\u003eCamera Connection 2 (Thread)\u003c\/td\u003e\n\u003ctd\u003eM48x0.75 male thread\u003c\/td\u003e\n\u003c\/tr\u003e\n\u003ctr\u003e\n\u003ctd\u003eCamera Connection 2 (Back Focus)\u003c\/td\u003e\n\u003ctd\u003e55mm or 91.5mm\u003c\/td\u003e\n\u003c\/tr\u003e\n\u003ctr\u003e\n\u003ctd\u003eAdditional Threads\u003c\/td\u003e\n\u003ctd\u003eM63x1 female thread for photo adaptions\u003c\/td\u003e\n\u003c\/tr\u003e\n\u003ctr\u003e\n\u003ctd\u003eHousing Diameter\u003c\/td\u003e\n\u003ctd\u003e67mm\u003c\/td\u003e\n\u003c\/tr\u003e\n\u003ctr\u003e\n\u003ctd\u003eLength\u003c\/td\u003e\n\u003ctd\u003e87.5mm (without male thread)\u003c\/td\u003e\n\u003c\/tr\u003e\n\u003c\/tbody\u003e\n\u003c\/table\u003e\n\u003c\/li\u003e\n\u003cli\u003e\n\u003cul class=\"DAV-grid\"\u003e\n\u003c\/ul\u003e\n\u003c\/li\u003e\n\n\u003cli\u003e\n\u003ca href=\"https:\/\/davidastro.com\/pages\/svbony-warranty-policy\" rel=\"noopener\" target=\"_blank\"\u003eSVBONY Warranty Policy\u003c\/a\u003e\n\u003c\/li\u003e\n\u003c\/ul\u003e","brand":"SVBONY","offers":[{"title":"Default Title","offer_id":52861262528797,"sku":"SV-W9161A","price":168.0,"currency_code":"CAD","in_stock":true}],"thumbnail_url":"\/\/cdn.shopify.com\/s\/files\/1\/0753\/5280\/1565\/files\/SVBONY-SV209-1-0x-Flattener-for-SV550-80F6-M63x1-Connection-Black-1_aeaa0c9a-d3bc-4129-bcdc-146c73679a89.jpg?v=1788883554","url":"https:\/\/davidastro.com\/products\/svbony-sv209-1-0x-field-flattener-for-sv550-80f6","provider":"David Astro","version":"1.0","type":"link"}