{"product_id":"svbony-sv209-1-0x-field-flattener-sv550-80","title":"SVBONY SV209 1.0x Field Flattener for SV550 80 f\/6","description":"\u003cp\u003e\u003cimg src=\"https:\/\/cdn.shopify.com\/s\/files\/1\/0686\/0049\/6239\/files\/W9161A_20251206140407_1913_20260814161229_5009.webp?v=1791670442\" alt=\"SVBONY SV209 1.0x field flattener for SV550 80 f\/6\" style=\"max-width:100%;height:auto;\"\u003e\u003c\/p\u003e\u003ch3\u003e\u003cstrong\u003eProduct Overview\u003c\/strong\u003e\u003c\/h3\u003e\u003cp\u003eThe SVBONY SV209 is a 1.0x field flattener for the SVBONY SV550 80 f\/6 refractor. It corrects the field curvature of the SV550 80 so stars stay sharp toward the edge, without changing focal length, and delivers a 45 mm fully illuminated field that supports full-frame sensors. It is a two-lens, fully multi-coated design in a 67 mm housing, 87.5 mm long without the male thread, and comes as three parts: the flattener, an M63 extension tube and an M48 adapter ring with a built-in 2″ filter thread.\u003c\/p\u003e\u003cp\u003e\u003cimg src=\"https:\/\/cdn.shopify.com\/s\/files\/1\/0686\/0049\/6239\/files\/1_20260310104456_7060.webp?v=1791670442\" alt=\"SVBONY SV209 field flattener components\" style=\"max-width:100%;height:auto;\"\u003e\u003c\/p\u003e\u003ch3\u003e\u003cstrong\u003eWho It's For\u003c\/strong\u003e\u003c\/h3\u003e\u003cp\u003eThis is a good match if you image with an SV550 80 f\/6 and want a flat field across an APS-C or full-frame sensor at the telescope's native focal length.\u003c\/p\u003e\u003ch3\u003e\u003cstrong\u003eKey Features \u0026amp; Design\u003c\/strong\u003e\u003c\/h3\u003e\u003cul\u003e\n\u003cli\u003e\n\u003cstrong\u003e1.0x factor:\u003c\/strong\u003e no change in focal length at the focal plane.\u003c\/li\u003e\n\u003cli\u003e\n\u003cstrong\u003e45 mm fully illuminated field\u003c\/strong\u003e for full-frame sensors.\u003c\/li\u003e\n\u003cli\u003e\u003cstrong\u003eTwo-lens FMC optics.\u003c\/strong\u003e\u003c\/li\u003e\n\u003cli\u003e\n\u003cstrong\u003eM63×1 telescope connection\u003c\/strong\u003e after removing the SV550's 2″ adapter ring.\u003c\/li\u003e\n\u003cli\u003e\n\u003cstrong\u003eM48 adapter ring with 2″ filter thread\u003c\/strong\u003e, so any 2″ filter can sit in the train.\u003c\/li\u003e\n\u003cli\u003e\n\u003cstrong\u003eConnection for the SV210\u003c\/strong\u003e camera angle adjuster (sold separately).\u003c\/li\u003e\n\u003c\/ul\u003e\u003cp\u003e\u003cimg src=\"https:\/\/cdn.shopify.com\/s\/files\/1\/0686\/0049\/6239\/files\/2_20260310104509_3853.webp?v=1791670443\" alt=\"SVBONY SV209 field flattener M63 and M48 threads\" style=\"max-width:100%;height:auto;\"\u003e\u003c\/p\u003e\u003ch3\u003e\u003cstrong\u003eOptical Design\u003c\/strong\u003e\u003c\/h3\u003e\u003cp\u003eThe two-element flattener sits in the converging cone of the SV550 80's objective and reshapes its curved focal surface into a flat one, keeping the 1.0x focal length. The M63 extension tube and the M48 adapter ring together set the flattener's back focal length to 55 mm at the M48 male thread; the camera side also offers an M63×1 female thread with a 103 mm working distance for other photo adaptations. SVBONY also lists a 91.5 mm working distance at the M48 thread.\u003c\/p\u003e\u003cp\u003e\u003cimg src=\"https:\/\/cdn.shopify.com\/s\/files\/1\/0686\/0049\/6239\/files\/3_20260310104512_4338.webp?v=1791670442\" alt=\"SVBONY SV209 field flattener assembly order\" style=\"max-width:100%;height:auto;\"\u003e\u003c\/p\u003e\u003ch3\u003e\u003cstrong\u003eRecommended Uses\u003c\/strong\u003e\u003c\/h3\u003e\u003cul\u003e\n\u003cli\u003e\n\u003cstrong\u003eDeep-sky imaging\u003c\/strong\u003e with the SV550 80 f\/6 on full-frame and APS-C cameras.\u003c\/li\u003e\n\u003cli\u003e\n\u003cstrong\u003eWide-field nebula and Milky Way fields\u003c\/strong\u003e at the native 1.0x focal length.\u003c\/li\u003e\n\u003cli\u003e\n\u003cstrong\u003eFilter imaging\u003c\/strong\u003e with a 2″ filter in the M48 adapter ring.\u003c\/li\u003e\n\u003c\/ul\u003e\u003ch3\u003e\u003cstrong\u003eCompatibility and Accessory Notes\u003c\/strong\u003e\u003c\/h3\u003e\u003cul\u003e\n\u003cli\u003e\n\u003cstrong\u003eTelescope:\u003c\/strong\u003e SVBONY SV550 80 f\/6 (80 mm APO).\u003c\/li\u003e\n\u003cli\u003e\n\u003cstrong\u003eAssembly:\u003c\/strong\u003e unscrew the SV550's 2″ adapter ring, then connect the flattener, the M63 extension tube and the M48 adapter ring in the order SVBONY shows; the order matters for the 55 mm figure.\u003c\/li\u003e\n\u003cli\u003e\n\u003cstrong\u003eCamera:\u003c\/strong\u003e SVBONY's example uses a Canon-compatible camera at 55 mm; any camera can be spaced to 55 mm from the M48 thread.\u003c\/li\u003e\n\u003cli\u003e\n\u003cstrong\u003eSV210 CAA:\u003c\/strong\u003e the SV209 connects to the SV210 camera angle adjuster for rotating the framing.\u003c\/li\u003e\n\u003c\/ul\u003e\u003cp\u003e\u003cimg src=\"https:\/\/cdn.shopify.com\/s\/files\/1\/0686\/0049\/6239\/files\/6386046315254080184411718.jpg?v=1791669954\" alt=\"SVBONY SV209 1.0x field flattener with SV210 camera angle adjuster connection\" style=\"max-width:100%;height:auto;\"\u003e\u003c\/p\u003e\u003cp\u003eIf you would like the train worked out for your camera, filter and rotator, send us your parts list and we will add it up with you.\u003c\/p\u003e\u003ch3\u003e\u003cstrong\u003eWhat's in the Box\u003c\/strong\u003e\u003c\/h3\u003e\u003cul\u003e\n\u003cli\u003eSV550 80 OTA field flattener\u003c\/li\u003e\n\u003cli\u003eM63 extension tube\u003c\/li\u003e\n\u003cli\u003eM48 adapter ring\u003c\/li\u003e\n\u003c\/ul\u003e\u003ch3\u003e\u003cstrong\u003eGood to Know Before You Order\u003c\/strong\u003e\u003c\/h3\u003e\u003cul\u003e\n\u003cli\u003e\n\u003cstrong\u003eMatched to the SV550 80 f\/6:\u003c\/strong\u003e the SV209 0.8x reducer for the SV550 122 is a different product.\u003c\/li\u003e\n\u003cli\u003e\n\u003cstrong\u003eSpacing:\u003c\/strong\u003e 55 mm from the M48 thread to the sensor; the corners are where the spacing shows.\u003c\/li\u003e\n\u003cli\u003e\n\u003cstrong\u003eMount not included;\u003c\/strong\u003e SVBONY does not publish a weight for this flattener.\u003c\/li\u003e\n\u003cli\u003e\n\u003cstrong\u003eImaging only:\u003c\/strong\u003e it has no application in a visual train.\u003c\/li\u003e\n\u003c\/ul\u003e\u003ch3\u003e\u003cstrong\u003eFrequently Asked Questions\u003c\/strong\u003e\u003c\/h3\u003e\u003cp\u003e\u003cstrong\u003eIs it difficult to set up?\u003c\/strong\u003e\u003c\/p\u003e\u003cp\u003eIt takes a few minutes: remove the SV550's 2″ adapter ring, thread on the three parts in order, and space the camera to 55 mm from the M48 thread with the T-ring or spacers.\u003c\/p\u003e\u003cp\u003e\u003cstrong\u003eDoes it reduce focal length?\u003c\/strong\u003e\u003c\/p\u003e\u003cp\u003eNo. It is a 1.0x flattener.\u003c\/p\u003e\u003cp\u003e\u003cstrong\u003eWill it cover full frame?\u003c\/strong\u003e\u003c\/p\u003e\u003cp\u003eSVBONY publishes a 45 mm fully illuminated field supporting full-frame sensors.\u003c\/p\u003e\u003cp\u003e\u003cstrong\u003eCan I use 2″ filters?\u003c\/strong\u003e\u003c\/p\u003e\u003cp\u003eYes. The M48 adapter ring has a built-in 2″ filter thread.\u003c\/p\u003e\u003ch3\u003e\u003cstrong\u003eBottom Line\u003c\/strong\u003e\u003c\/h3\u003e\u003cp\u003eIn short: a two-lens 1.0x field flattener for the SV550 80 f\/6, with a 45 mm illuminated field, 55 mm backfocus at its M48 output and a 2″ filter thread, for flat full-frame deep-sky images.\u003c\/p\u003e","brand":"SvBony","offers":[{"title":"Default Title","offer_id":67722296885359,"sku":"W9161A","price":170.99,"currency_code":"CAD","in_stock":true}],"thumbnail_url":"\/\/cdn.shopify.com\/s\/files\/1\/0686\/0049\/6239\/files\/W9161A_20251206140407_1913_20260814161229_5009.webp?v=1791670442","url":"https:\/\/ontariotelescope.com\/products\/svbony-sv209-1-0x-field-flattener-sv550-80","provider":"Ontario Telescope and Accessories","version":"1.0","type":"link"}