{"product_id":"svbony-sv227-1-25-sho-5nm-filter-set","title":"SVBONY SV227 1.25″ SHO 5nm Narrowband Filter Set (H-alpha, OIII, SII)","description":"\u003cp\u003e\u003cimg src=\"https:\/\/cdn.shopify.com\/s\/files\/1\/0686\/0049\/6239\/files\/w9187a-0_20251231163447_0084.webp?v=1791670370\" alt=\"SVBONY SV227 1.25 inch SHO 5nm filter set\" 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 1.25″ SHO set is three 5 nm narrowband imaging filters, H-alpha at 656.3 nm, OIII at 500.7 nm and SII at 671.6 nm, for building Hubble-palette and bicolour images of emission nebulae. Each filter has a peak transmission of at least 90%, average blocking of OD5 across 300–1000 nm and a 26 mm clear aperture, in a thin 6061T aluminium cell with an M28.5 x 0.6 thread. The set weighs 140 g, and each filter 15 g.\u003c\/p\u003e\u003cp\u003e\u003cimg src=\"https:\/\/cdn.shopify.com\/s\/files\/1\/0686\/0049\/6239\/files\/w9187a-2_20250908141530_1031.jpg?v=1791670371\" alt=\"SVBONY SV227 1.25 inch H-alpha, OIII and SII filters\" 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 a 1.25″ filter wheel or drawer, especially from light-polluted skies where narrowband isolates the target lines from sky glow.\u003c\/p\u003e\u003ch3\u003e\u003cstrong\u003eKey Features \u0026amp; Design\u003c\/strong\u003e\u003c\/h3\u003e\u003cul\u003e\n\u003cli\u003e\n\u003cstrong\u003eComplete SHO set:\u003c\/strong\u003e H-alpha, OIII and SII in matching 5 nm bandwidths.\u003c\/li\u003e\n\u003cli\u003e\n\u003cstrong\u003e≥90% peak transmission:\u003c\/strong\u003e at each emission line.\u003c\/li\u003e\n\u003cli\u003e\n\u003cstrong\u003eOD5 average cut-off depth:\u003c\/strong\u003e strong rejection of unwanted light from 300 to 1000 nm.\u003c\/li\u003e\n\u003cli\u003e\n\u003cstrong\u003eDouble-sided polishing and coating:\u003c\/strong\u003e single-piece substrates, not two-piece cemented, with 1\/4λ surface flatness and 30″ parallelism.\u003c\/li\u003e\n\u003cli\u003e\n\u003cstrong\u003e26 mm clear aperture:\u003c\/strong\u003e in a thin metal cell to maximise the opening.\u003c\/li\u003e\n\u003c\/ul\u003e\u003cp\u003e\u003cimg src=\"https:\/\/cdn.shopify.com\/s\/files\/1\/0686\/0049\/6239\/files\/w9187a-3_20250908141531_9869.jpg?v=1791670370\" alt=\"SVBONY SV227 1.25 inch SHO filter cells and coatings\" style=\"max-width:100%;height:auto;\"\u003e\u003c\/p\u003e\u003ch3\u003e\u003cstrong\u003eOptical Design\u003c\/strong\u003e\u003c\/h3\u003e\u003cp\u003eEach filter is an interference filter on a 1.85 mm substrate. Narrowing the passband to 5 nm around the target line raises the contrast of faint nebulosity against the background, and the OD5 blocking keeps light pollution and moonlight out of the frame. Surface quality is 60\/40, with 1\/4λ surface parallelism.\u003c\/p\u003e\u003cp\u003e\u003cimg src=\"https:\/\/cdn.shopify.com\/s\/files\/1\/0686\/0049\/6239\/files\/w9187a-5_20250908141536_3539.jpg?v=1791670370\" alt=\"SVBONY SV227 1.25 inch SHO filter optical detail\" 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 (Hubble palette) imaging\u003c\/strong\u003e of emission nebulae and supernova remnants.\u003c\/li\u003e\n\u003cli\u003e\n\u003cstrong\u003eHOO bicolour imaging\u003c\/strong\u003e with the H-alpha and OIII filters.\u003c\/li\u003e\n\u003cli\u003e\n\u003cstrong\u003eImaging under city skies\u003c\/strong\u003e and around the Moon.\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 M28.5 x 0.6 male, single thread, standard 1.25″ size (Φ31.75 x 7 mm cell).\u003c\/li\u003e\n\u003cli\u003e\n\u003cstrong\u003eFilter holders:\u003c\/strong\u003e any 1.25″ filter wheel, drawer slider or camera nosepiece with the standard thread.\u003c\/li\u003e\n\u003cli\u003e\n\u003cstrong\u003eSensor size:\u003c\/strong\u003e 1.25″ filters suit small and medium sensors; larger sensors are usually paired with 2″ filters.\u003c\/li\u003e\n\u003c\/ul\u003e\u003cp\u003e\u003cimg src=\"https:\/\/cdn.shopify.com\/s\/files\/1\/0686\/0049\/6239\/files\/w9187a-6_20250908141539_1310.jpg?v=1791670370\" alt=\"SVBONY SV227 1.25 inch SHO filter thread and fit\" style=\"max-width:100%;height:auto;\"\u003e\u003c\/p\u003e\u003ch3\u003e\u003cstrong\u003eWhat's in the Box\u003c\/strong\u003e\u003c\/h3\u003e\u003cul\u003e\n\u003cli\u003e1.25″ H-alpha filter x1\u003c\/li\u003e\n\u003cli\u003e1.25″ SII filter x1\u003c\/li\u003e\n\u003cli\u003e1.25″ OIII filter x1\u003c\/li\u003e\n\u003cli\u003ePP storage cases x3\u003c\/li\u003e\n\u003c\/ul\u003e\u003cp\u003e\u003cimg src=\"https:\/\/cdn.shopify.com\/s\/files\/1\/0686\/0049\/6239\/files\/w9187a-7_20250908141541_0329.jpg?v=1791670370\" alt=\"SVBONY SV227 1.25 inch SHO filter set with storage cases\" 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\u003eImaging filters:\u003c\/strong\u003e designed for camera imaging, with mono cameras getting the most from each line.\u003c\/li\u003e\n\u003cli\u003e\u003cstrong\u003eNot for solar use.\u003c\/strong\u003e\u003c\/li\u003e\n\u003cli\u003e\n\u003cstrong\u003eWheel or drawer:\u003c\/strong\u003e a filter wheel or drawer makes changing between the three filters straightforward.\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. Each filter threads into a standard 1.25″ filter wheel position, drawer slider or camera nosepiece.\u003c\/p\u003e\u003cp\u003e\u003cstrong\u003eCan I use them with a colour camera?\u003c\/strong\u003e\u003c\/p\u003e\u003cp\u003eThey work, but a colour sensor records each line on only part of its pixels; a mono camera uses the full sensor for each filter.\u003c\/p\u003e\u003cp\u003e\u003cstrong\u003eWhat bandwidth are they?\u003c\/strong\u003e\u003c\/p\u003e\u003cp\u003e5 nm for all three filters.\u003c\/p\u003e\u003ch3\u003e\u003cstrong\u003eBottom Line\u003c\/strong\u003e\u003c\/h3\u003e\u003cp\u003eIn short: a matched set of 1.25″ 5 nm H-alpha, OIII and SII filters with ≥90% peak transmission and OD5 blocking, for narrowband nebula imaging.\u003c\/p\u003e","brand":"SvBony","offers":[{"title":"Default Title","offer_id":67722281779311,"sku":"W9187A","price":239.39,"currency_code":"CAD","in_stock":true}],"thumbnail_url":"\/\/cdn.shopify.com\/s\/files\/1\/0686\/0049\/6239\/files\/w9187a-0_20251231163447_0084.webp?v=1791670370","url":"https:\/\/ontariotelescope.com\/products\/svbony-sv227-1-25-sho-5nm-filter-set","provider":"Ontario Telescope and Accessories","version":"1.0","type":"link"}