{"product_id":"svbony-sv227-2-sii-5nm-filter","title":"SVBONY SV227 2″ SII 5nm Narrowband Filter","description":"\u003cp\u003e\u003cimg src=\"https:\/\/cdn.shopify.com\/s\/files\/1\/0686\/0049\/6239\/files\/6385397542214813458448612.jpg?v=1791670054\" alt=\"SVBONY SV227 2 inch SII 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 SII is a 2″ narrowband imaging filter with a 5 nm passband centred on the 672 nm sulfur II emission 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 CNC-machined, black-anodised 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\/6385397542271866472935008.jpg?v=1791670054\" alt=\"SVBONY SV227 SII 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 and are building SHO (Hubble palette) data, using 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 672 nm:\u003c\/strong\u003e isolates sulfur II emission from light pollution and moonlight.\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\u003eCoatings:\u003c\/strong\u003e multi-layer anti-reflection coatings applied by electron-beam evaporation with ion-assisted deposition.\u003c\/li\u003e\n\u003cli\u003e\n\u003cstrong\u003eOptical glass:\u003c\/strong\u003e SVBONY specifies German optical glass, 60\/40 surface quality, 1\/4λ surface parallelism and 30″ parallelism.\u003c\/li\u003e\n\u003cli\u003e\n\u003cstrong\u003eMetal cell:\u003c\/strong\u003e CNC-machined, black-anodised and laser-engraved.\u003c\/li\u003e\n\u003c\/ul\u003e\u003cp\u003e\u003cimg src=\"https:\/\/cdn.shopify.com\/s\/files\/1\/0686\/0049\/6239\/files\/6385397542306319549485514.jpg?v=1791670054\" alt=\"SVBONY SV227 SII 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\/6385397542344500281061317.jpg?v=1791670054\" alt=\"SVBONY SV227 SII 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\/6385397542378800322229235.jpg?v=1791670054\" alt=\"SVBONY SV227 SII 5nm filter cell construction panel\" style=\"max-width:100%;height:auto;\"\u003e\u003c\/p\u003e\u003ch3\u003e\u003cstrong\u003eOptical Design\u003c\/strong\u003e\u003c\/h3\u003e\u003cp\u003eSII is usually the faintest of the three SHO lines, so a narrow 5 nm passband and deep blocking are what keep the background dark enough to record it. The interference coating passes the 672 nm line at ≥90% while rejecting the rest of the 300–1000 nm range at ≥OD5, which also blocks the near infrared that a separate IR-cut filter would otherwise handle.\u003c\/p\u003e\u003cp\u003e\u003cimg src=\"https:\/\/cdn.shopify.com\/s\/files\/1\/0686\/0049\/6239\/files\/6385397542436005566693443.jpg?v=1791670054\" alt=\"SVBONY SV227 SII 5nm filter design 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\/6385397542528187257188455.jpg?v=1791670055\" alt=\"SVBONY SV227 SII 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\u003eSHO imaging\u003c\/strong\u003e of emission nebulae and supernova remnants alongside H-alpha and OIII.\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″ H-alpha and OIII 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\/6385397542585268411438632.jpg?v=1791670054\" alt=\"SVBONY SV227 SII 5nm filter compatibility 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\/6385397542614922596939829.jpg?v=1791670054\" alt=\"SVBONY SV227 SII 5nm filter detail 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\u003cstrong\u003eNot for solar use.\u003c\/strong\u003e\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 use it on an f\/3.6 astrograph?\u003c\/strong\u003e\u003c\/p\u003e\u003cp\u003eSVBONY rates it for f\/4 and slower.\u003c\/p\u003e\u003cp\u003e\u003cstrong\u003eDo I still need an IR-cut filter?\u003c\/strong\u003e\u003c\/p\u003e\u003cp\u003eNo. The ≥OD5 blocking covers the near infrared.\u003c\/p\u003e\u003ch3\u003e\u003cstrong\u003eBottom Line\u003c\/strong\u003e\u003c\/h3\u003e\u003cp\u003eIn short: a 2″, 5 nm SII filter at 672 nm with ≥90% peak transmission and ≥OD5 blocking, for SHO imaging at f\/4 and slower.\u003c\/p\u003e","brand":"SvBony","offers":[{"title":"SII Filter","offer_id":67722288726127,"sku":"W9187DA","price":133.0,"currency_code":"CAD","in_stock":true}],"thumbnail_url":"\/\/cdn.shopify.com\/s\/files\/1\/0686\/0049\/6239\/files\/w9187da-0_20251231163326_4185.webp?v=1791670410","url":"https:\/\/ontariotelescope.com\/products\/svbony-sv227-2-sii-5nm-filter","provider":"Ontario Telescope and Accessories","version":"1.0","type":"link"}