{"id":3901,"date":"2025-03-06T20:43:48","date_gmt":"2025-03-06T19:43:48","guid":{"rendered":"https:\/\/deep-space-astronomy.geekworkers.dev\/produit\/filtre-chroma-sii-3nm-ultra\/"},"modified":"2025-06-03T10:40:56","modified_gmt":"2025-06-03T08:40:56","slug":"filtre-chroma-sii-3nm-ultra","status":"publish","type":"product","link":"https:\/\/deep-space-astronomy.ch\/en\/product\/filtre-chroma-sii-3nm-ultra\/","title":{"rendered":"Chroma SII 3nm Ultra filter - 2\u2033 mounted"},"content":{"rendered":"<h3>SII 3nm filter from Chroma Technology<\/h3>\n<p>Visit <strong>3nm SII filter from Chroma Technology<\/strong> is an ultra-narrow band filter designed to isolate the emission line of ionized sulfur (SII) at 672 nm. This filter is particularly suited to imaging nebulae, where sulfur plays a key role in spectral emission. It is ideal for astrophotographers seeking maximum contrast and clear separation of the different spectral lines.<\/p>\n<h4>Key features<\/h4>\n<ul>\n<li><strong>Bandwidth :<\/strong> 3 nm, enabling extremely precise isolation of the SII line, while effectively blocking unwanted wavelengths (light pollution, H-alpha, etc.).<\/li>\n<li><strong>Targeted emission rays :<\/strong> SII doublet at 671.6 nm and 673.1 nm, characteristic of sulfur-rich nebulae.<\/li>\n<li><strong>High transmission :<\/strong> Up to 90 % at 672 nm, guaranteeing an excellent signal-to-noise ratio.<\/li>\n<li><strong>Optical quality :<\/strong> Surface polished to an accuracy of \u03bb\/4.<\/li>\n<li><strong>Multi-layer anti-reflective coatings :<\/strong> On both sides to minimize halos and stray reflections.<\/li>\n<li><strong>Substrate thickness :<\/strong> Approx. 3 mm \u00b1 0.05 mm, made from a unique optical glass substrate for exceptional durability.<\/li>\n<li><strong>Parallelism :<\/strong> &lt;30 arcsec, guaranteeing optimum image quality.<\/li>\n<\/ul>\n<h4>Applications<\/h4>\n<ul>\n<li><strong>Imaging SII-rich nebulae:<\/strong>\n<ul>\n<li>Perfect for capturing objects such as the Crab Nebula, Rosette Nebula and Veil Nebula.<\/li>\n<\/ul>\n<\/li>\n<li><strong>Reducing light pollution :<\/strong>\n<ul>\n<li>Effectively blocks unwanted wavelengths, even in urban or suburban environments.<\/li>\n<\/ul>\n<\/li>\n<li><strong>Advanced astrophotography :<\/strong>\n<ul>\n<li>Ideal complement to H-alpha and OIII filters for creating images in scientific palettes (SHO or Hubble palette).<\/li>\n<\/ul>\n<\/li>\n<li><strong>Compatibility with high-speed systems :<\/strong>\n<ul>\n<li>Works perfectly with focal ratios up to f\/4.0.<\/li>\n<li>An optimized version is available for high-speed systems (f\/2.8 to f\/3.6), to compensate for blueshift.<\/li>\n<\/ul>\n<\/li>\n<\/ul>\n<h4>Technical highlights<\/h4>\n<ul>\n<li><strong>Exceptional durability :<\/strong>\n<ul>\n<li>Sputter coatings guarantee long-term spectral stability.<\/li>\n<li>Resistant to extreme variations in temperature and humidity.<\/li>\n<\/ul>\n<\/li>\n<li><strong>Anti-halos design :<\/strong> Anti-reflective coatings eliminate halos around bright stars, delivering sharp, detailed images.<\/li>\n<li><strong>Universal compatibility :<\/strong> Compatible with most filter wheels and drawers on the market.<\/li>\n<\/ul>\n<h4>Available formats<\/h4>\n<ul>\n<li><strong>Mounted :<\/strong> 1,25\", 2\"<\/li>\n<li><strong>Unmounted :<\/strong> Customized formats (31 mm, 36 mm).<\/li>\n<\/ul>\n<h4>Conclusion<\/h4>\n<p>The filter <strong>Chroma SII 3nm<\/strong> is an essential tool for astrophotographers seeking to capture the subtle details of nebulae rich in ionized sulfur. Its optical precision, high transmission and ability to effectively reduce light pollution make it an essential choice for deep-sky imaging.<\/p>","protected":false},"excerpt":{"rendered":"<p>Filtre SII 3nm de Chroma Technology Le filtre SII 3nm de Chroma Technology est un filtre \u00e0 bande ultra-\u00e9troite con\u00e7u pour isoler la raie d\u2019\u00e9mission du soufre ionis\u00e9 (SII) \u00e0 672 nm. Ce filtre est particuli\u00e8rement adapt\u00e9 \u00e0 l\u2019imagerie des n\u00e9buleuses o\u00f9 le soufre joue un r\u00f4le cl\u00e9 dans l\u2019\u00e9mission spectrale. Il est id\u00e9al pour [&hellip;]<\/p>\n","protected":false},"featured_media":3899,"comment_status":"open","ping_status":"closed","template":"","meta":[],"product_brand":[582],"product_cat":[780],"product_tag":[],"class_list":{"0":"post-3901","1":"product","2":"type-product","3":"status-publish","4":"has-post-thumbnail","6":"product_brand-chroma","7":"product_cat-filtres-bande-etroite","9":"first","10":"on_supplier","11":"taxable","12":"shipping-taxable","13":"purchasable","14":"product-type-simple"},"_links":{"self":[{"href":"https:\/\/deep-space-astronomy.ch\/en\/wp-json\/wp\/v2\/product\/3901","targetHints":{"allow":["GET"]}}],"collection":[{"href":"https:\/\/deep-space-astronomy.ch\/en\/wp-json\/wp\/v2\/product"}],"about":[{"href":"https:\/\/deep-space-astronomy.ch\/en\/wp-json\/wp\/v2\/types\/product"}],"replies":[{"embeddable":true,"href":"https:\/\/deep-space-astronomy.ch\/en\/wp-json\/wp\/v2\/comments?post=3901"}],"wp:featuredmedia":[{"embeddable":true,"href":"https:\/\/deep-space-astronomy.ch\/en\/wp-json\/wp\/v2\/media\/3899"}],"wp:attachment":[{"href":"https:\/\/deep-space-astronomy.ch\/en\/wp-json\/wp\/v2\/media?parent=3901"}],"wp:term":[{"taxonomy":"product_brand","embeddable":true,"href":"https:\/\/deep-space-astronomy.ch\/en\/wp-json\/wp\/v2\/product_brand?post=3901"},{"taxonomy":"product_cat","embeddable":true,"href":"https:\/\/deep-space-astronomy.ch\/en\/wp-json\/wp\/v2\/product_cat?post=3901"},{"taxonomy":"product_tag","embeddable":true,"href":"https:\/\/deep-space-astronomy.ch\/en\/wp-json\/wp\/v2\/product_tag?post=3901"}],"curies":[{"name":"wp","href":"https:\/\/api.w.org\/{rel}","templated":true}]}}