{"product_id":"antlia-2-5nm-h-alpha-ultra-series-filter-2-ha-ultra-2-5nm-2","title":"Antlia 2.5nm H-Alpha Ultra Series Filter - 2\" - HA-ULTRA-2.5NM-2","description":"\u003cp style=\"text-align: left;\"\u003eThis very narrowband 2.5 nm H-Alpha filter from Antlia is part of their Ultra series and comes in a 2\" threaded filter cell that is designed to be screwed on to the 2\" receptacle of your astrophotography accessory, including a 2\" filter wheel or filter drawer.  \u003c\/p\u003e\n\u003ch3 style=\"text-align: center;\"\u003eAntlia 2.5nm Ultra Series H-Alpha Filter - 2\" Mounted\u003c\/h3\u003e\n\u003cp\u003e\u003cspan\u003eAll Antlia 2.5nm Ultra Series Filters are made with quartz glass and undergo precisely controlled coating processes to ensure optimal performance. The \u003c\/span\u003e\u003cspan\u003e2.5nm \u003c\/span\u003e\u003cspan\u003eUltra series is designed with a FWHM (full width half maximum) of 2.5nm +0.3\/-0.1nm and a transmission efficiency \u0026gt;92-95% at the Central Wavelength\u003c\/span\u003e\u003cspan\u003e.\u003c\/span\u003e\u003c\/p\u003e\n\u003cp\u003e\u003cspan\u003eThe quartz glass possesses\u003c\/span\u003e\u003cspan\u003e \u003c\/span\u003e\u003cspan\u003ean ultra-low thermal expansion coefficient\u003c\/span\u003e\u003cspan\u003e \u003c\/span\u003e\u003cspan\u003ewith outstanding thermal and mechanical properties.\u003c\/span\u003e\u003cspan\u003e \u003c\/span\u003e\u003cspan\u003eWhen combined with advanced coating processes, these filters exhibit remarkable durability for imaging and research in the most challenging environmental conditions.\u003c\/span\u003e\u003cspan\u003e\u003c\/span\u003e\u003c\/p\u003e\n\u003cp\u003e\u003cspan\u003eCompared to the 3nm Pro series, the 2.5nm Ultra series, coated on quartz glass, exhibits higher transmittance with Ha\/SII\u003c\/span\u003e\u003cspan\u003e≥\u003c\/span\u003e\u003cspan\u003e95% and OIII\u003c\/span\u003e\u003cspan\u003e≥\u003c\/span\u003e\u003cspan\u003e92%. These filters are estimated to improve signal by 20-30% in your images. Additionally, the\u003c\/span\u003e\u003cspan\u003e \u003c\/span\u003e\u003cspan\u003eUltra series boasts a narrower FWHM of 2.5nm+0.3\/-0.1nm,\u003c\/span\u003e\u003cspan\u003e \u003c\/span\u003e\u003cspan\u003eresulting in an exceptionally high Signal to Noise Ratio\u003c\/span\u003e\u003cspan\u003e for deep sky photography.\u003c\/span\u003e\u003c\/p\u003e\n\u003cp\u003eImportant:  Do not use when viewing or imaging the Sun!\u003c\/p\u003e\n\u003ch3\u003eHighlights \u0026amp; Application \u003c\/h3\u003e\n\u003cp class=\"p\"\u003e\u003cspan\u003e- \u003c\/span\u003e\u003cspan\u003eHigh transmittance （Ha\/SII\u003c\/span\u003e\u003cspan\u003e≥\u003c\/span\u003e\u003cspan\u003e9\u003c\/span\u003e\u003cspan\u003e5\u003c\/span\u003e\u003cspan\u003e%，OIII\u003c\/span\u003e\u003cspan\u003e≥\u003c\/span\u003e\u003cspan\u003e92\u003c\/span\u003e\u003cspan\u003e%）and the narrow FWHM\u003c\/span\u003e\u003cspan\u003e \u003c\/span\u003e\u003cspan\u003e2.\u003c\/span\u003e\u003cspan\u003e5\u003c\/span\u003e\u003cspan\u003enm +0.\u003c\/span\u003e\u003cspan\u003e3\u003c\/span\u003e\u003cspan\u003e\/-0.1\u003c\/span\u003e\u003cspan\u003enm\u003c\/span\u003e\u003cspan\u003e \u003c\/span\u003e\u003cspan\u003eto maximize contrast\u003c\/span\u003e\u003cspan\u003e;\u003c\/span\u003e\u003cspan\u003e\u003c\/span\u003e\u003c\/p\u003e\n\u003cp class=\"p\"\u003e\u003cspan\u003e- \u003c\/span\u003e\u003cspan\u003eFlat-top spectrum minimizes the loss in transmission due to the Center Wavelength (CWL)-shift\u003c\/span\u003e\u003cspan\u003e;\u003c\/span\u003e\u003cspan\u003e\u003c\/span\u003e\u003c\/p\u003e\n\u003cp class=\"p\"\u003e\u003cspan\u003e- O\u003c\/span\u003e\u003cspan\u003eut of band blocking specification is designed\u003c\/span\u003e\u003cspan\u003e to\u003c\/span\u003e\u003cspan\u003e OD5 (0.001%)\u003c\/span\u003e\u003cspan\u003e to\u003c\/span\u003e\u003cspan\u003e block interference from other wavelengths and minimize halos around bright stars\u003c\/span\u003e\u003cspan\u003e;\u003c\/span\u003e\u003cspan\u003e\u003c\/span\u003e\u003c\/p\u003e\n\u003cp class=\"p\"\u003e\u003cspan\u003e- \u003c\/span\u003e\u003cspan\u003eMade of quartz glass, excellent durability and thermal stability\u003c\/span\u003e\u003cspan\u003e, \u003c\/span\u003e\u003cspan\u003ebetter fracture resistance and scratch resistance, improved coating resilience to cleaning;\u003c\/span\u003e\u003cspan\u003e\u003c\/span\u003e\u003c\/p\u003e\n\u003cp class=\"p\"\u003e\u003cspan\u003e- Filters are resistant to scratches；\u003c\/span\u003e\u003cspan\u003e\u003c\/span\u003e\u003c\/p\u003e\n\u003cp class=\"p\"\u003e\u003cspan\u003e- \u003c\/span\u003e\u003cspan\u003eIdentical filter thickness to existing standards and double-sided fine polishing , with utmost care for parfocality\u003c\/span\u003e\u003cspan\u003e;\u003c\/span\u003e\u003c\/p\u003e\n\u003cp class=\"p\"\u003e\u003cspan\u003e- The SHO 2.5\u003c\/span\u003e\u003cspan\u003enm Ultra filters are recommended for use in optics with a Focus Ratio of ≥ f\/3.5 for best optical performance;\u003c\/span\u003e\u003c\/p\u003e\n\u003cp class=\"p\"\u003e\u003cspan\u003e- \u003c\/span\u003e\u003cspan\u003e100% of production are scanned individually, all transmission and blocking (OD) data in the box are actual, measured spectra and transmission\u003c\/span\u003e\u003cspan\u003e；\u003c\/span\u003e\u003cspan\u003e\u003c\/span\u003e\u003c\/p\u003e\n\u003cp class=\"p\"\u003e\u003cspan\u003e- \u003c\/span\u003e\u003cspan\u003eAll Antlia filters are coated to the edge of the substrate and unmounted narrowband filters are edge blackened to eliminate internal reflections from stray ligh\u003c\/span\u003e\u003cspan\u003et\u003c\/span\u003e\u003cspan\u003e；\u003c\/span\u003e\u003cspan\u003e\u003c\/span\u003e\u003c\/p\u003e\n\u003cp class=\"p\"\u003e\u003cspan\u003e-\u003c\/span\u003e\u003cspan\u003e \u003c\/span\u003e\u003cspan\u003eWarranty: \u003c\/span\u003e\u003cspan\u003e3\u003c\/span\u003e\u003cspan\u003e-years against delamination\u003c\/span\u003e\u003cspan\u003e.\u003c\/span\u003e\u003c\/p\u003e\n\u003cp\u003e\u003cstrong\u003eHydrogen-Alpha Filter Tech Specs:\u003c\/strong\u003e\u003c\/p\u003e\n\u003cp\u003eFWHM:  2.5nm +0.3\/-0.2nm\u003c\/p\u003e\n\u003cp\u003eCWL (Central Wavelength): 656.3nm\u003c\/p\u003e\n\u003cp\u003ePeak Transmission:  95%\u003c\/p\u003e\n\u003cp\u003eBlocking:  +\/-OD5\u003c\/p\u003e\n\u003cp\u003eFilter Thickness:  2 mm +\/- 0.05mm\u003c\/p\u003e\n\u003cp\u003e\u003cstrong\u003e\u003cspan\u003eFilter Ring:\u003c\/span\u003e\u003c\/strong\u003e\u003c\/p\u003e\n\u003cp\u003e\u003cspan\u003eAntlia standard ring: \u003c\/span\u003e\u003cspan\u003e2\u003c\/span\u003e\u003cspan\u003e’’\u003c\/span\u003e\u003cspan\u003e(M48*0.75)\u003c\/span\u003e\u003c\/p\u003e\n\u003cp\u003e\u003cspan\u003eUltra-thin filter cell to minimize vignetting while maximizing clear aperture \u003c\/span\u003e\u003c\/p\u003e\n\u003cp\u003e\u003cspan\u003eBlack Anodized Finish\u003c\/span\u003e\u003c\/p\u003e\n\u003cp\u003e\u003cspan\u003eLaser Engraving No Fading\u003c\/span\u003e\u003c\/p\u003e","brand":"Antlia","offers":[{"title":"Default Title","offer_id":41674785849457,"sku":"ATL-HA-ULTRA-1.5NM-2","price":537.95,"currency_code":"EUR","in_stock":true}],"thumbnail_url":"\/\/cdn.shopify.com\/s\/files\/1\/0851\/2766\/files\/HA-ULTRA-2.5NM-2_d0d17f7e-4ba9-483c-b941-84b32489cfc1.jpg?v=1776458921","url":"https:\/\/khanscope.com\/fr-fr\/products\/antlia-2-5nm-h-alpha-ultra-series-filter-2-ha-ultra-2-5nm-2","provider":"Khan Scope Centre","version":"1.0","type":"link"}