{"product_id":"svbony-sv220-1-25-7nm-h-alpha-oiii-dual-band-filter","title":"SVBONY SV220 1.25″ 7nm H-Alpha \u0026 OIII Dual-Band Filter","description":"\u003cp\u003e\u003cimg src=\"https:\/\/cdn.shopify.com\/s\/files\/1\/0686\/0049\/6239\/files\/6383229366022653233256396.jpg?v=1791669934\" alt=\"SVBONY SV220 1.25 inch 7nm H-alpha and OIII dual-band nebula filter key visual\" style=\"max-width:100%;height:auto;\"\u003e\u003c\/p\u003e\u003ch3\u003e\u003cstrong\u003eProduct Overview\u003c\/strong\u003e\u003c\/h3\u003e\u003cp\u003eThe SVBONY SV220 1.25″ is a dual-band nebula filter that passes two 7 nm-wide bands centred on OIII (500.7 nm) and H-alpha (656.3 nm) and blocks the rest of the 300–1100 nm range to better than OD5. Peak transmission is above 90% at 500.7 nm and above 94% at 656.3 nm. The 1.85 mm substrate sits in a 1.25″ cell with a 26 mm clear aperture and a single M28.5 x 0.6 male thread, and the filter weighs 7 g.\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 emission nebulae with a one-shot colour camera and want narrowband-style contrast without moving to a monochrome camera and filter wheel, particularly from a light-polluted backyard or under a bright Moon.\u003c\/p\u003e\u003cp\u003e\u003cimg src=\"https:\/\/cdn.shopify.com\/s\/files\/1\/0686\/0049\/6239\/files\/6387056599689075354202720.jpg?v=1791669934\" alt=\"SVBONY SV220 7nm dual-band filter for one-shot colour cameras\" style=\"max-width:100%;height:auto;\"\u003e\u003c\/p\u003e\u003ch3\u003e\u003cstrong\u003eKey Features \u0026amp; Design\u003c\/strong\u003e\u003c\/h3\u003e\u003cul\u003e\n\u003cli\u003e\n\u003cstrong\u003eTwo 7 nm passbands:\u003c\/strong\u003e OIII at 500.7 nm and H-alpha at 656.3 nm, the two strongest emission lines in most nebulae.\u003c\/li\u003e\n\u003cli\u003e\n\u003cstrong\u003eOD5 out-of-band blocking:\u003c\/strong\u003e suppresses sodium and mercury street-light lines and sky glow.\u003c\/li\u003e\n\u003cli\u003e\n\u003cstrong\u003eHigh transmission:\u003c\/strong\u003e above 90% (OIII) and above 94% (H-alpha) at peak.\u003c\/li\u003e\n\u003cli\u003e\n\u003cstrong\u003eOptical quality:\u003c\/strong\u003e 60\/40 surface quality and 1\/4λ surface parallelism.\u003c\/li\u003e\n\u003cli\u003e\n\u003cstrong\u003eStandard 1.25″ cell:\u003c\/strong\u003e M28.5 x 0.6 thread for 1.25″ nosepieces, filter wheels and drawers.\u003c\/li\u003e\n\u003c\/ul\u003e\u003cp\u003e\u003cimg src=\"https:\/\/cdn.shopify.com\/s\/files\/1\/0686\/0049\/6239\/files\/6387089761778992623065617.jpg?v=1791669934\" alt=\"SVBONY SV220 7nm dual-band filter light pollution suppression\" style=\"max-width:100%;height:auto;\"\u003e\u003c\/p\u003e\u003ch3\u003e\u003cstrong\u003eOptical Design\u003c\/strong\u003e\u003c\/h3\u003e\u003cp\u003eA dual-band filter is an interference coating with two narrow transmission windows. By passing only the OIII and H-alpha lines, it lets the nebula's own emission through while rejecting the broadband glow of artificial light and moonlight, which darkens the background and raises contrast. It does not add brightness to the target; it removes what competes with it. On a colour sensor the H-alpha signal lands in the red pixels and OIII in the green and blue pixels, giving a bicolour result in a single exposure. SVBONY notes that the OIII passband is relatively wide for its class, which favours signal collection in that channel.\u003c\/p\u003e\u003cp\u003e\u003cimg src=\"https:\/\/cdn.shopify.com\/s\/files\/1\/0686\/0049\/6239\/files\/6387056657250575711229458.jpg?v=1791669934\" alt=\"SVBONY SV220 7nm H-alpha and OIII passband transmission\" 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\u003eEmission nebulae:\u003c\/strong\u003e H II regions such as the North America, Rosette and Heart nebulae.\u003c\/li\u003e\n\u003cli\u003e\n\u003cstrong\u003ePlanetary nebulae and supernova remnants:\u003c\/strong\u003e strong OIII targets such as the Veil.\u003c\/li\u003e\n\u003cli\u003e\n\u003cstrong\u003eUrban and moonlit imaging:\u003c\/strong\u003e extends usable nights for colour-camera imagers.\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\u003eCameras:\u003c\/strong\u003e designed for one-shot colour (OSC) astronomy cameras; it also works with mono cameras as a combined Ha+OIII filter.\u003c\/li\u003e\n\u003cli\u003e\n\u003cstrong\u003eMounting:\u003c\/strong\u003e threads into any 1.25″ nosepiece, filter wheel or filter drawer with an M28.5 x 0.6 thread.\u003c\/li\u003e\n\u003cli\u003e\n\u003cstrong\u003eSensor size:\u003c\/strong\u003e the 26 mm clear aperture suits 1.25″-class sensors; larger sensors are better served by the 2″ SV220.\u003c\/li\u003e\n\u003cli\u003e\n\u003cstrong\u003eCompanion filter:\u003c\/strong\u003e SVBONY pairs it with the SV220 7nm SII \u0026amp; OIII filter for Hubble-palette (SHO) colour from an OSC camera.\u003c\/li\u003e\n\u003c\/ul\u003e\u003cp\u003e\u003cimg src=\"https:\/\/cdn.shopify.com\/s\/files\/1\/0686\/0049\/6239\/files\/6383229366295169827739688.jpg?v=1791669934\" alt=\"SVBONY SV220 1.25 inch dual-band filter detail panel\" style=\"max-width:100%;height:auto;\"\u003e\u003c\/p\u003e\u003cp\u003e\u003cimg src=\"https:\/\/cdn.shopify.com\/s\/files\/1\/0686\/0049\/6239\/files\/6383229366353398772517711.jpg?v=1791669934\" alt=\"SVBONY SV220 1.25 inch dual-band filter M28.5 thread and cell\" style=\"max-width:100%;height:auto;\"\u003e\u003c\/p\u003e\u003cp\u003eIf you are not sure whether a 1.25″ or 2″ filter suits your sensor and telescope, send us your camera model and we will work it out with you.\u003c\/p\u003e\u003ch3\u003e\u003cstrong\u003eGood to Know Before You Order\u003c\/strong\u003e\u003c\/h3\u003e\u003cul\u003e\n\u003cli\u003e\n\u003cstrong\u003eImaging filter:\u003c\/strong\u003e it has no application in visual observing and is not a solar filter.\u003c\/li\u003e\n\u003cli\u003e\n\u003cstrong\u003eEmission targets:\u003c\/strong\u003e galaxies, reflection nebulae and star clusters are broadband targets and gain little from it.\u003c\/li\u003e\n\u003cli\u003e\n\u003cstrong\u003eWeight figure:\u003c\/strong\u003e SVBONY's spec table lists 7 g; a feature note on the same page lists 5.4 g.\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\u003eNo. It threads onto a 1.25″ camera nosepiece or into a filter wheel or drawer like any 1.25″ filter.\u003c\/p\u003e\u003cp\u003e\u003cstrong\u003eDoes it work with a colour camera?\u003c\/strong\u003e\u003c\/p\u003e\u003cp\u003eYes. It is designed for one-shot colour cameras.\u003c\/p\u003e\u003cp\u003e\u003cstrong\u003eWill it help in the city?\u003c\/strong\u003e\u003c\/p\u003e\u003cp\u003eYes. The OD5 blocking suppresses street-light emission and sky glow, which is where dual-band filters do their most useful work.\u003c\/p\u003e\u003cp\u003e\u003cstrong\u003eCan I use it for visual observing?\u003c\/strong\u003e\u003c\/p\u003e\u003cp\u003eIt is an imaging filter and is not intended for visual use.\u003c\/p\u003e\u003ch3\u003e\u003cstrong\u003eBottom Line\u003c\/strong\u003e\u003c\/h3\u003e\u003cp\u003eIn short: a 1.25″ 7 nm H-alpha and OIII dual-band filter with OD5 blocking that gives colour-camera imagers high-contrast emission-nebula data from light-polluted skies.\u003c\/p\u003e","brand":"SvBony","offers":[{"title":"SV220 1.25″","offer_id":67722262773871,"sku":"W9172A","price":106.88,"currency_code":"CAD","in_stock":true}],"thumbnail_url":"\/\/cdn.shopify.com\/s\/files\/1\/0686\/0049\/6239\/files\/w9172a-1_20250807133600_8978_20260810144122_5751.webp?v=1791670283","url":"https:\/\/ontariotelescope.com\/products\/svbony-sv220-1-25-7nm-h-alpha-oiii-dual-band-filter","provider":"Ontario Telescope and Accessories","version":"1.0","type":"link"}