{"product_id":"svbony-sv115-2-oiii-18nm-filter","title":"SVBONY SV115 2″ OIII 18nm Narrowband Filter","description":"\u003cp\u003e\u003cimg src=\"https:\/\/cdn.shopify.com\/s\/files\/1\/0686\/0049\/6239\/files\/svbony-oiii-2inch_20250806104729_2751_20260820171152_4634.webp?v=1791670173\" alt=\"SVBONY SV115 2″ OIII 18nm filter\" style=\"max-width:100%;height:auto;\"\u003e\u003c\/p\u003e\u003ch3\u003e\u003cstrong\u003eProduct Overview\u003c\/strong\u003e\u003c\/h3\u003e\u003cp\u003eThe SVBONY SV115 2″ (item F9186B) is an O-III narrowband filter with an 18 ± 2 nm passband centred near 500 nm. It transmits 90% at 495.9 nm and 500.7 nm and blocks across 400–700 nm, cutting light from mercury and sodium street lamps and natural skyglow. The 1.85 mm glass carries dichroic and anti-reflection coatings to reduce glare and ghosting, in a standard 2″ cell that fits all 2″ eyepieces.\u003c\/p\u003e\u003ch3\u003e\u003cstrong\u003eWho It's For\u003c\/strong\u003e\u003c\/h3\u003e\u003cp\u003eThis is a good match if you observe through a 2″ focuser or diagonal and want higher-contrast views of emission nebulae, planetary nebulae and supernova remnants, including bright nebulae like M42 under heavy light pollution.\u003c\/p\u003e\u003cp\u003e\u003cimg src=\"https:\/\/cdn.shopify.com\/s\/files\/1\/0686\/0049\/6239\/files\/svbony-oiii-2inch_20250806104748_7972.jpg?v=1791670174\" alt=\"SVBONY SV115 2″ OIII filter\" 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\u003e18 ± 2 nm FWHM\u003c\/strong\u003e around the O-III lines.\u003c\/li\u003e\n\u003cli\u003e\n\u003cstrong\u003e90% transmission\u003c\/strong\u003e at 495.9 nm and 500.7 nm.\u003c\/li\u003e\n\u003cli\u003e\n\u003cstrong\u003e400–700 nm blocking\u003c\/strong\u003e against artificial light and skyglow.\u003c\/li\u003e\n\u003cli\u003e\n\u003cstrong\u003eDichroic and anti-reflection coatings:\u003c\/strong\u003e reduce glare and ghost images.\u003c\/li\u003e\n\u003cli\u003e\u003cstrong\u003e2″ cell, 1.85 mm glass.\u003c\/strong\u003e\u003c\/li\u003e\n\u003c\/ul\u003e\u003cp\u003e\u003cimg src=\"https:\/\/cdn.shopify.com\/s\/files\/1\/0686\/0049\/6239\/files\/svbony-oiii-2inch-11_20250806104820_2026.jpg?v=1791670174\" alt=\"SVBONY SV115 2″ OIII filter coatings\" style=\"max-width:100%;height:auto;\"\u003e\u003c\/p\u003e\u003ch3\u003e\u003cstrong\u003eOptical Design\u003c\/strong\u003e\u003c\/h3\u003e\u003cp\u003eThe filter passes a narrow band around the doubly-ionized oxygen emission that nebulae radiate strongly, and blocks most of the visible spectrum where light pollution and skyglow fall. The sky background darkens far more than the nebula, so faint structure becomes visible. It raises contrast rather than brightness, and SVBONY notes the best results come with large apertures under clear, dark skies with good seeing.\u003c\/p\u003e\u003ch3\u003e\u003cstrong\u003eRecommended Uses\u003c\/strong\u003e\u003c\/h3\u003e\u003cul\u003e\n\u003cli\u003e\n\u003cstrong\u003eSupernova remnants\u003c\/strong\u003e such as the Veil.\u003c\/li\u003e\n\u003cli\u003e\n\u003cstrong\u003ePlanetary nebulae\u003c\/strong\u003e and \u003cstrong\u003eemission nebulae\u003c\/strong\u003e.\u003c\/li\u003e\n\u003cli\u003e\n\u003cstrong\u003eM42 and other bright nebulae\u003c\/strong\u003e from light-polluted sites.\u003c\/li\u003e\n\u003c\/ul\u003e\u003cp\u003e\u003cimg src=\"https:\/\/cdn.shopify.com\/s\/files\/1\/0686\/0049\/6239\/files\/svbony-oiii-2inch-1_20250806104822_6308.jpg?v=1791670174\" alt=\"SVBONY SV115 2″ OIII filter cell\" style=\"max-width:100%;height:auto;\"\u003e\u003c\/p\u003e\u003ch3\u003e\u003cstrong\u003eCompatibility and Accessory Notes\u003c\/strong\u003e\u003c\/h3\u003e\u003cul\u003e\n\u003cli\u003e\n\u003cstrong\u003eSize:\u003c\/strong\u003e 2″, fits all 2″ eyepieces and 2″ diagonals.\u003c\/li\u003e\n\u003cli\u003e\n\u003cstrong\u003e1.25″ version:\u003c\/strong\u003e SVBONY also makes the SV115 in 1.25″ as a separate product.\u003c\/li\u003e\n\u003c\/ul\u003e\u003cp\u003e\u003cimg src=\"https:\/\/cdn.shopify.com\/s\/files\/1\/0686\/0049\/6239\/files\/6373000045712565875536384_20250806104827_4956.jpg?v=1791670174\" alt=\"SVBONY SV115 2″ OIII filter graphic\" 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\u003eContrast, not brightness:\u003c\/strong\u003e the filter does not remove light pollution or brighten objects; it darkens the background so O-III nebulae stand out.\u003c\/li\u003e\n\u003cli\u003e\n\u003cstrong\u003eTarget-specific:\u003c\/strong\u003e galaxies and star clusters do not benefit from an O-III filter.\u003c\/li\u003e\n\u003cli\u003e\n\u003cstrong\u003eWeight:\u003c\/strong\u003e SVBONY does not publish a weight for this filter.\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. Thread it onto a 2″ eyepiece barrel or into a 2″ diagonal.\u003c\/p\u003e\u003cp\u003e\u003cstrong\u003eDoes it work in the city?\u003c\/strong\u003e\u003c\/p\u003e\u003cp\u003eIt increases nebula contrast under light pollution, and SVBONY lists bright nebulae such as M42 as targets even under heavy light pollution.\u003c\/p\u003e\u003cp\u003e\u003cstrong\u003eWhich objects benefit most?\u003c\/strong\u003e\u003c\/p\u003e\u003cp\u003eEmission nebulae, planetary nebulae and supernova remnants.\u003c\/p\u003e\u003ch3\u003e\u003cstrong\u003eBottom Line\u003c\/strong\u003e\u003c\/h3\u003e\u003cp\u003eIn short: a 2″ 18 nm O-III filter with 90% line transmission and 400–700 nm blocking, for higher-contrast visual views of nebulae and supernova remnants.\u003c\/p\u003e","brand":"SvBony","offers":[{"title":"Default Title","offer_id":67722240327791,"sku":"F9186B","price":79.79,"currency_code":"CAD","in_stock":true}],"thumbnail_url":"\/\/cdn.shopify.com\/s\/files\/1\/0686\/0049\/6239\/files\/svbony-oiii-2inch_20250806104729_2751_20260820171152_4634.webp?v=1791670173","url":"https:\/\/ontariotelescope.com\/products\/svbony-sv115-2-oiii-18nm-filter","provider":"Ontario Telescope and Accessories","version":"1.0","type":"link"}