{"product_id":"svbony-sv227-2-h-alpha-5nm-filter","title":"SVBONY SV227 2″ H-Alpha 5nm Narrowband Filter","description":"\u003cp\u003e\u003cimg src=\"https:\/\/cdn.shopify.com\/s\/files\/1\/0686\/0049\/6239\/files\/6385397605919067707591016.jpg?v=1791670054\" alt=\"SVBONY SV227 2 inch H-alpha 5nm 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 SV227 H-alpha is a 2″ narrowband imaging filter with a 5 nm passband centred on the 656.3 nm hydrogen-alpha line. Peak transmission is at least 90%, blocking is ≥OD5 across 300–1000 nm, and the clear aperture is 44 mm. The 1.85 mm substrate sits in a thin CNC-machined, black-anodised aluminium cell with an M48 x 0.75 thread, and SVBONY lists the net weight as 12.5 g.\u003c\/p\u003e\u003cp\u003e\u003cimg src=\"https:\/\/cdn.shopify.com\/s\/files\/1\/0686\/0049\/6239\/files\/6385397605975736149633031.jpg?v=1791670054\" alt=\"SVBONY SV227 H-alpha 5nm filter feature panel\" 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 emission nebulae with a monochrome camera, whether for H-alpha luminance, HOO bicolour or full SHO, and use a 2″ filter wheel or drawer to cover a larger sensor.\u003c\/p\u003e\u003ch3\u003e\u003cstrong\u003eKey Features \u0026amp; Design\u003c\/strong\u003e\u003c\/h3\u003e\u003cul\u003e\n\u003cli\u003e\n\u003cstrong\u003e5 nm at 656.3 nm:\u003c\/strong\u003e isolates hydrogen-alpha emission from sodium and mercury-vapour light pollution.\u003c\/li\u003e\n\u003cli\u003e\n\u003cstrong\u003e≥90% peak transmission\u003c\/strong\u003e and \u003cstrong\u003e≥OD5 blocking\u003c\/strong\u003e from 300 to 1000 nm.\u003c\/li\u003e\n\u003cli\u003e\n\u003cstrong\u003eMulti-layer anti-reflection coatings\u003c\/strong\u003e on German optical glass.\u003c\/li\u003e\n\u003cli\u003e\n\u003cstrong\u003eThin aluminium cell:\u003c\/strong\u003e maximises clear aperture; CNC-machined, black-anodised and laser-engraved.\u003c\/li\u003e\n\u003cli\u003e\n\u003cstrong\u003eSurface quality 60\/40,\u003c\/strong\u003e 1\/4λ surface parallelism and 30″ parallelism.\u003c\/li\u003e\n\u003c\/ul\u003e\u003cp\u003e\u003cimg src=\"https:\/\/cdn.shopify.com\/s\/files\/1\/0686\/0049\/6239\/files\/6385397606005497049327774.jpg?v=1791670055\" alt=\"SVBONY SV227 H-alpha 5nm filter narrowband passband 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\/6385397606062209781692397.jpg?v=1791670055\" alt=\"SVBONY SV227 H-alpha 5nm filter coating 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\/6386052953626902506599897.jpg?v=1791670055\" alt=\"SVBONY SV227 H-alpha 5nm filter design panel\" style=\"max-width:100%;height:auto;\"\u003e\u003c\/p\u003e\u003ch3\u003e\u003cstrong\u003eOptical Design\u003c\/strong\u003e\u003c\/h3\u003e\u003cp\u003eH-alpha is the brightest line in most emission nebulae, and a 5 nm passband records it with a very dark background even under city skies. The interference coating passes 656.3 nm at ≥90% and rejects the rest of the 300–1000 nm range at ≥OD5, so no separate IR-cut filter is needed.\u003c\/p\u003e\u003cp\u003e\u003cimg src=\"https:\/\/cdn.shopify.com\/s\/files\/1\/0686\/0049\/6239\/files\/6385397606149293813656958.jpg?v=1791670054\" alt=\"SVBONY SV227 H-alpha 5nm filter cell construction 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\/6385397606178884833021087.jpg?v=1791670055\" alt=\"SVBONY SV227 H-alpha 5nm filter specification panel\" 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\u003eH-alpha imaging\u003c\/strong\u003e of emission nebulae, on its own or as luminance for colour data.\u003c\/li\u003e\n\u003cli\u003e\n\u003cstrong\u003eHOO and SHO imaging\u003c\/strong\u003e alongside OIII and SII filters.\u003c\/li\u003e\n\u003cli\u003e\n\u003cstrong\u003eImaging from light-polluted skies\u003c\/strong\u003e or with the Moon up.\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\u003eThread:\u003c\/strong\u003e M48 x 0.75, single thread, standard 2″ size.\u003c\/li\u003e\n\u003cli\u003e\n\u003cstrong\u003eHolders:\u003c\/strong\u003e 2″ filter wheels, filter drawer sliders and 2″ nosepieces.\u003c\/li\u003e\n\u003cli\u003e\n\u003cstrong\u003eMatching filters:\u003c\/strong\u003e SVBONY makes the SV227 2″ OIII and SII 5 nm filters and a 2″ SHO set.\u003c\/li\u003e\n\u003c\/ul\u003e\u003cp\u003e\u003cimg src=\"https:\/\/cdn.shopify.com\/s\/files\/1\/0686\/0049\/6239\/files\/6385397606292906252503802.jpg?v=1791670055\" alt=\"SVBONY SV227 H-alpha 5nm filter compatibility panel\" style=\"max-width:100%;height:auto;\"\u003e\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\u003eFocal ratio:\u003c\/strong\u003e SVBONY lists it as unsuitable for telescopes faster than f\/4.\u003c\/li\u003e\n\u003cli\u003e\n\u003cstrong\u003eNot for solar use:\u003c\/strong\u003e this is a night-sky imaging filter, not a solar H-alpha filter.\u003c\/li\u003e\n\u003cli\u003e\n\u003cstrong\u003eThis listing is the filter only;\u003c\/strong\u003e SVBONY also offers it with a 2″ holder.\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 into a 2″ filter wheel position, drawer slider or nosepiece like any standard M48 filter.\u003c\/p\u003e\u003cp\u003e\u003cstrong\u003eCan I look at the Sun with it?\u003c\/strong\u003e\u003c\/p\u003e\u003cp\u003eNo. It is a deep-sky imaging filter; solar H-alpha viewing needs a dedicated solar telescope or filter system.\u003c\/p\u003e\u003cp\u003e\u003cstrong\u003eWill it work with a colour camera?\u003c\/strong\u003e\u003c\/p\u003e\u003cp\u003eYes, though a colour sensor records H-alpha on its red pixels only; a mono camera uses every pixel.\u003c\/p\u003e\u003ch3\u003e\u003cstrong\u003eBottom Line\u003c\/strong\u003e\u003c\/h3\u003e\u003cp\u003eIn short: a 2″, 5 nm H-alpha filter at 656.3 nm with ≥90% peak transmission and ≥OD5 blocking, for nebula imaging at f\/4 and slower.\u003c\/p\u003e","brand":"SvBony","offers":[{"title":"H-Alpha Filter","offer_id":67722299113583,"sku":"W9187DB","price":133.0,"currency_code":"CAD","in_stock":true}],"thumbnail_url":"\/\/cdn.shopify.com\/s\/files\/1\/0686\/0049\/6239\/files\/w9187db-1_20250908144153_3780_20260810152133_0115.webp?v=1791670449","url":"https:\/\/ontariotelescope.com\/products\/svbony-sv227-2-h-alpha-5nm-filter","provider":"Ontario Telescope and Accessories","version":"1.0","type":"link"}