{"product_id":"player-one-1-25-ha-7nm-narrowband-filter","title":"Player One 1.25\" Ha 7nm Narrowband Filter","description":"\u003cp\u003e\u003cstrong\u003eOverview.\u003c\/strong\u003e The Player One 1.25\" Ha 7nm Narrowband Filter is an S-series hydrogen-alpha (Hα) emission-line filter for monochrome deep-sky astrophotography. It transmits a narrow 7nm ±0.5nm band centered on the hydrogen-alpha emission of nebulae while blocking the rest of the spectrum, so faint emission structure is recorded with high contrast even under moderate light pollution. The filter is built on a high-quality optical glass substrate with a multi-layer composite coating and threads into standard 1.25\" filter mounts.\u003c\/p\u003e\u003cp\u003e\u003cstrong\u003eWho It's For.\u003c\/strong\u003e This filter suits imagers using cooled or uncooled monochrome cameras who want to capture emission nebulae, isolate the Hα channel of an SHO (Hubble-palette) dataset, or extend imaging into moonlit and light-polluted nights.\u003c\/p\u003e\u003cp\u003e\u003cstrong\u003eKey Features \u0026amp; Design.\u003c\/strong\u003e\u003c\/p\u003e\u003cul\u003e\n\u003cli\u003e\n\u003cstrong\u003eNarrow 7nm passband:\u003c\/strong\u003e a 7nm ±0.5nm FWHM isolates the hydrogen-alpha line and rejects most skyglow and broadband light pollution.\u003c\/li\u003e\n\u003cli\u003e\n\u003cstrong\u003eDeep blocking:\u003c\/strong\u003e OD3 blocking (less than 0.1% transmission off-band) with NIR cutoff across 700–1100nm suppresses stray and out-of-band light.\u003c\/li\u003e\n\u003cli\u003e\n\u003cstrong\u003eHigh in-band throughput:\u003c\/strong\u003e approximately 90% peak transmittance preserves signal on faint targets.\u003c\/li\u003e\n\u003cli\u003e\n\u003cstrong\u003eMulti-layer composite coating:\u003c\/strong\u003e applied to a high-quality optical glass substrate for durability and consistent response.\u003c\/li\u003e\n\u003cli\u003e\n\u003cstrong\u003eStandard 1.25\" format:\u003c\/strong\u003e M28.5×0.6 cell threads fit common 1.25\" filter wheels, drawers, and threaded accessories.\u003c\/li\u003e\n\u003c\/ul\u003e\u003cp\u003e\u003cstrong\u003eOptical\/Mechanical Design.\u003c\/strong\u003e The filter passes a 7nm ±0.5nm FWHM band on the hydrogen-alpha emission line and holds OD3 off-band blocking (\u0026lt;0.1% transmission) with the near-infrared blocked from 700–1100nm. Peak in-band transmittance is about 90%. Both surfaces are polished to 1\/4 lambda surface accuracy on a 2.0 ±0.03 mm optical glass substrate carrying a multi-layer composite coating. The anodized cell uses M28.5×0.6 (1.25\") threads and measures 7.5mm overall (5mm body plus 2.5mm thread).\u003c\/p\u003e\u003cp\u003e\u003cstrong\u003eRecommended Uses.\u003c\/strong\u003e Narrowband imaging of emission nebulae, supernova remnants, and HII regions; the Hα channel in bicolor (HOO) and tricolor (SHO) narrowband processing; and continued deep-sky capture during bright-moon or light-polluted conditions.\u003c\/p\u003e\u003cp\u003e\u003cstrong\u003eCompatibility \u0026amp; Accessory Notes.\u003c\/strong\u003e The M28.5×0.6 cell fits standard 1.25\" filter wheels, filter drawers, and 1.25\" nosepieces and eyepiece-thread accessories. It pairs naturally with matching Player One 1.25\" OIII 7nm and SII 7nm filters for a complete SHO set. Narrowband filters are intended for monochrome imaging cameras; on one-shot-color sensors the effective throughput is reduced.\u003c\/p\u003e\u003cp\u003e\u003cstrong\u003eGood to Know Before You Order.\u003c\/strong\u003e\u003c\/p\u003e\u003cul\u003e\n\u003cli\u003e\n\u003cstrong\u003eIndividual center wavelength:\u003c\/strong\u003e Player One does not publish a numeric center wavelength for this line on the product page, so it is not stated here.\u003c\/li\u003e\n\u003cli\u003e\n\u003cstrong\u003eShipping weight:\u003c\/strong\u003e a packaged weight is not published by the manufacturer; contact us if you need it before ordering.\u003c\/li\u003e\n\u003cli\u003e\n\u003cstrong\u003eCamera type:\u003c\/strong\u003e narrowband results are strongest with monochrome cameras.\u003c\/li\u003e\n\u003c\/ul\u003e\u003cp\u003e\u003cstrong\u003eFAQ.\u003c\/strong\u003e\u003c\/p\u003e\u003cp\u003e\u003cstrong\u003eIs it difficult to set up?\u003c\/strong\u003e No. The filter threads into any standard 1.25\" filter wheel, drawer, or nosepiece and requires no adjustment once installed.\u003c\/p\u003e\u003cp\u003e\u003cstrong\u003eWill it help under light pollution?\u003c\/strong\u003e Yes. The 7nm passband rejects most broadband skyglow, so Hα emission is recorded with strong contrast even from suburban skies.\u003c\/p\u003e\u003cp\u003e\u003cstrong\u003eCan I use it with a color camera?\u003c\/strong\u003e It is designed for monochrome cameras; a one-shot-color sensor will still pass the band but with reduced efficiency.\u003c\/p\u003e\u003cp\u003e\u003cstrong\u003eBottom Line.\u003c\/strong\u003e A well-coated 7nm hydrogen-alpha filter in the convenient 1.25\" format, the Player One 1.25\" Ha 7nm delivers high-contrast emission-line imaging and forms the Hα channel of a full narrowband set.\u003c\/p\u003e","brand":"Player One Astronomy","offers":[{"title":"Default Title","offer_id":53834272505967,"sku":"HA7-125","price":180.6,"currency_code":"CAD","in_stock":true}],"thumbnail_url":"\/\/cdn.shopify.com\/s\/files\/1\/0686\/0049\/6239\/files\/HSO125-SET-600x600.jpg?v=1784239444","url":"https:\/\/ontariotelescope.com\/products\/player-one-1-25-ha-7nm-narrowband-filter","provider":"Ontario Telescope and Accessories","version":"1.0","type":"link"}