{"product_id":"svbony-sv220-2-inch-3nm-narrowband-filter","title":"SVBONY SV220 2″ 3nm H-Alpha \u0026 OIII Dual-Band Filter (W9198B)","description":"\u003cdiv style=\"background:#112c38;color:#fff;padding:24px;border-radius:12px;margin-bottom:24px\"\u003e\n\u003cp style=\"margin:0 0 8px;color:#75dce0\"\u003eSVBONY SV220 · W9198B · 2″ MOUNTED\u003c\/p\u003e\n\u003ch2 style=\"color:#fff;margin:0 0 12px\"\u003eTwo nebula emission bands. One filter.\u003c\/h2\u003e\n\u003cp style=\"margin:0\"\u003eCapture H-alpha and OIII together with the SV220 3nm dual-band imaging filter, designed for revealing emission-nebula structure with a colour astronomy camera.\u003c\/p\u003e\n\u003c\/div\u003e\n\u003cp\u003eThe \u003cstrong\u003eSVBONY SV220 W9198B\u003c\/strong\u003e is a \u003cstrong\u003e2-inch mounted H-alpha and OIII dual-band filter\u003c\/strong\u003e. Its two narrow transmission windows isolate red hydrogen-alpha emission at \u003cstrong\u003e656.3nm\u003c\/strong\u003e and blue-green oxygen-III emission at \u003cstrong\u003e500.7nm\u003c\/strong\u003e, helping suppress unwanted background light during deep-sky imaging.\u003c\/p\u003e\n\u003cfigure style=\"margin:24px 0\"\u003e\u003cimg src=\"https:\/\/cdn.shopify.com\/s\/files\/1\/0523\/1650\/4241\/files\/sv220-w9198b-0_20251125105032_6111.webp?v=1793823788\" alt=\"SVBONY SV220 2-inch 3nm H-alpha and OIII dual-band filter – W9198B\" loading=\"lazy\" style=\"display:block;width:100%;max-width:800px;height:auto;margin:0 auto\"\u003e\u003cfigcaption\u003eSVBONY SV220 2-inch 3nm H-alpha and OIII dual-band filter – W9198B\u003c\/figcaption\u003e\u003c\/figure\u003e\n\u003ch2\u003eWhat the 3nm dual-band design does\u003c\/h2\u003e\n\u003cp\u003eBoth emission bands are recorded in the same exposure, making this a practical option for \u003cstrong\u003eone-shot-colour astronomy cameras\u003c\/strong\u003e. Each window has a nominal 3nm bandwidth; SVBONY specifies a \u003cstrong\u003e3 ± 1nm FWHM\u003c\/strong\u003e tolerance. FWHM describes the width of each transmission band at half its peak transmission.\u003c\/p\u003e\n\u003cp\u003eThe narrow windows reject much of the surrounding spectrum. This can improve separation between nebular emission and sky background under light-polluted or moonlit skies. Exposure length and total integration time still depend on your telescope, camera, target and conditions.\u003c\/p\u003e\n\u003ch2\u003eChoose it for emission nebulae\u003c\/h2\u003e\n\u003cp\u003eUse it for objects with H-alpha and\/or OIII emission, including emission nebulae, planetary nebulae and supernova remnants. Examples include the Orion, Eagle and Dumbbell nebulae. Their response depends on the emission present in each object.\u003c\/p\u003e\n\u003cp\u003eFor galaxies, reflection nebulae and star clusters, a broadband approach generally preserves more of the target’s light and colour. This filter records H-alpha and OIII together; a separate SII dataset is needed for a three-channel SHO image.\u003c\/p\u003e\n\u003cfigure style=\"margin:24px 0\"\u003e\u003cimg src=\"https:\/\/cdn.shopify.com\/s\/files\/1\/0523\/1650\/4241\/files\/w9198b-2_20250901175702_2296.jpg?v=1793823788\" alt=\"SVBONY SV220 3nm dual-band imaging filter detail\" loading=\"lazy\" style=\"display:block;width:100%;max-width:800px;height:auto;margin:0 auto\"\u003e\u003cfigcaption\u003eSVBONY SV220 3nm dual-band imaging filter detail\u003c\/figcaption\u003e\u003c\/figure\u003e\n\u003ch2\u003eFitting and telescope compatibility\u003c\/h2\u003e\n\u003cp\u003eThe mounted filter uses a \u003cstrong\u003e2-inch M48 × 0.75 thread\u003c\/strong\u003e. Choose a drawer, wheel or holder designed to accept this mounted format and check the available cell clearance before ordering.\u003c\/p\u003e\n\u003cp\u003eSVBONY lists a \u003cstrong\u003e44mm clear aperture\u003c\/strong\u003e. Suitability for a larger sensor also depends on filter-to-sensor distance and the telescope’s light cone; a 2-inch filter alone does not guarantee freedom from vignetting.\u003c\/p\u003e\n\u003cp\u003e\u003cstrong\u003eFast optics:\u003c\/strong\u003e SVBONY cautions against use at \u003cstrong\u003ef\/5 or faster\u003c\/strong\u003e, including RASA-type systems, because interference-filter band shift can reduce transmission at the required emission lines. Check suitability before selecting this filter for a fast imaging system.\u003c\/p\u003e\n\u003ch2\u003eSpecifications\u003c\/h2\u003e\n\u003ctable\u003e\u003ctbody\u003e\n\u003ctr\u003e\n\u003cth scope=\"row\"\u003eModel \/ manufacturer SKU\u003c\/th\u003e\n\u003ctd\u003eSV220 \/ W9198B\u003c\/td\u003e\n\u003c\/tr\u003e\n\u003ctr\u003e\n\u003cth scope=\"row\"\u003eFormat\u003c\/th\u003e\n\u003ctd\u003e2-inch mounted imaging filter\u003c\/td\u003e\n\u003c\/tr\u003e\n\u003ctr\u003e\n\u003cth scope=\"row\"\u003ePassbands\u003c\/th\u003e\n\u003ctd\u003eH-alpha 656.3nm and OIII 500.7nm\u003c\/td\u003e\n\u003c\/tr\u003e\n\u003ctr\u003e\n\u003cth scope=\"row\"\u003eBandwidth per passband\u003c\/th\u003e\n\u003ctd\u003eNominal 3nm; specified FWHM 3 ± 1nm\u003c\/td\u003e\n\u003c\/tr\u003e\n\u003ctr\u003e\n\u003cth scope=\"row\"\u003eMounting thread\u003c\/th\u003e\n\u003ctd\u003eM48 × 0.75\u003c\/td\u003e\n\u003c\/tr\u003e\n\u003ctr\u003e\n\u003cth scope=\"row\"\u003eClear aperture\u003c\/th\u003e\n\u003ctd\u003e44mm\u003c\/td\u003e\n\u003c\/tr\u003e\n\u003ctr\u003e\n\u003cth scope=\"row\"\u003eOut-of-band blocking\u003c\/th\u003e\n\u003ctd\u003eManufacturer-rated average OD5 across the specified 300–1050nm blocking range\u003c\/td\u003e\n\u003c\/tr\u003e\n\u003ctr\u003e\n\u003cth scope=\"row\"\u003ePrimary application\u003c\/th\u003e\n\u003ctd\u003eH-alpha\/OIII emission-nebula astrophotography with colour cameras\u003c\/td\u003e\n\u003c\/tr\u003e\n\u003c\/tbody\u003e\u003c\/table\u003e\n\u003cp\u003e\u003cstrong\u003eVersion supplied:\u003c\/strong\u003e W9198B, the 2-inch 3nm H-alpha\/OIII filter. Check the SKU when comparing other SV220 sizes and bandwidths.\u003c\/p\u003e\n\u003cp\u003e\u003cstrong\u003eFor imaging use. Never use this filter to observe or photograph the Sun without an appropriate dedicated solar filtration system.\u003c\/strong\u003e\u003c\/p\u003e\n\u003cp\u003eExplore our \u003ca href=\"\/collections\/svbony-telescope-filters\"\u003eSVBONY telescope filter range\u003c\/a\u003e, or ask Dark Clear Skies for help matching a filter to your camera and telescope.\u003c\/p\u003e","brand":"SVBONY","offers":[{"title":"Default","offer_id":55721161326968,"sku":"W9198B","price":269.99,"currency_code":"GBP","in_stock":true}],"thumbnail_url":"\/\/cdn.shopify.com\/s\/files\/1\/0523\/1650\/4241\/files\/sv220-w9198b-0_20251125105032_6111.webp?v=1793823788","url":"https:\/\/www.darkclearskies.co.uk\/products\/svbony-sv220-2-inch-3nm-narrowband-filter","provider":"Dark Clear Skies ","version":"1.0","type":"link"}