{"id":7031,"date":"2025-04-22T16:47:49","date_gmt":"2025-04-22T14:47:49","guid":{"rendered":"https:\/\/deep-space-astronomy.ch\/?post_type=product&#038;p=7031"},"modified":"2026-03-29T17:53:48","modified_gmt":"2026-03-29T15:53:48","slug":"filtres-sii-antlia-3nm-pro","status":"publish","type":"product","link":"https:\/\/deep-space-astronomy.ch\/en\/product\/filtres-sii-antlia-3nm-pro\/","title":{"rendered":"Antlia 3nm Pro SII filter"},"content":{"rendered":"<h3 style=\"text-align: center;\">Antlia 3nm Pro SII filter<\/h3>\n<p>The Antlia SII 3nm Pro filter optimizes the FWHM at 3nm. By reducing the bandwidth, this filter improves the contrast of emission targets by reducing spurious background signal. It is designed to deliver a transmission of 88% at the 672.4nm line, guaranteeing optimum signal and good nebula definition.<\/p>\n<p>Wider narrowband filters often suffer significant transmission losses due to center wavelength shift (CWL). The 3nm Pro filter guarantees &gt;88% transmission within \u00b11nm of the center band, enabling compatibility with lenses as fast as f\/3 without significant signal loss.<\/p>\n<p>Out-of-band rejection is rated OD5 (0.001%), ensuring an excellent signal-to-noise ratio and effective cutting of unwanted wavelengths. This filter is designed to limit halos around bright stars.<\/p>\n<h3>Application and performance<\/h3>\n<ul>\n<li>High transmission and minimal bandwidth for optimum contrast<\/li>\n<li>Steep spectral profile to reduce halos<\/li>\n<li>One-piece substrate to eliminate internal reflections<\/li>\n<li>Target objects: SII emission nebulae, planetary nebulae, Wolf-Rayet, supernova remnants<\/li>\n<li>Can be used in polluted areas or in dark skies<\/li>\n<li>Allows photography even in the presence of the Moon<\/li>\n<li>Compatible up to f\/3 with minimal signal loss<\/li>\n<li>Blackened edges to prevent reflections on unmounted models<\/li>\n<li>Superior optical reliability, less post-shooting processing<\/li>\n<li>Designed only for deep-sky objects containing SII emissions<\/li>\n<\/ul>\n<h3>Technical specifications<\/h3>\n<table>\n<thead>\n<tr>\n<th>Parameter<\/th>\n<th>Value<\/th>\n<\/tr>\n<\/thead>\n<tbody>\n<tr>\n<td>Substrate<\/td>\n<td>Optics, unglued monoblock<\/td>\n<\/tr>\n<tr>\n<td>Thickness<\/td>\n<td>2mm \u00b10.05mm (1.25\u2033, 2\u2033, 31mm, 36mm), 3mm \u00b10.05mm (50mm, 50x50mm)<\/td>\n<\/tr>\n<tr>\n<td>FWHM<\/td>\n<td>3nm<\/td>\n<\/tr>\n<tr>\n<td>Center wavelength (CWL)<\/td>\n<td>672.4nm<\/td>\n<\/tr>\n<tr>\n<td>Maximum transmission<\/td>\n<td>&gt;88%<\/td>\n<\/tr>\n<tr>\n<td>Out-of-band discharge<\/td>\n<td>OD5 (0.001%) from 300 to 1000nm<\/td>\n<\/tr>\n<tr>\n<td>Surface quality<\/td>\n<td>S\/D 60\/40 (MIL-O-13830 standard)<\/td>\n<\/tr>\n<tr>\n<td>Transmitted wavefront<\/td>\n<td>\u03bb\/4 or better<\/td>\n<\/tr>\n<tr>\n<td>Parallelism<\/td>\n<td>&lt; 30 arcsec<\/td>\n<\/tr>\n<tr>\n<td>Warranty<\/td>\n<td>3 years against delamination<\/td>\n<\/tr>\n<\/tbody>\n<\/table>\n<h3>Spectral curve<\/h3>\n<div class=\"image-placeholder\"><img fetchpriority=\"high\" decoding=\"async\" class=\"size-full wp-image-7045 aligncenter\" src=\"https:\/\/deep-space-astronomy.ch\/wp-content\/uploads\/2025\/04\/Antlia-SII-3nm-Pro-Curve.png\" alt=\"\" width=\"1345\" height=\"768\" srcset=\"https:\/\/deep-space-astronomy.ch\/wp-content\/uploads\/2025\/04\/Antlia-SII-3nm-Pro-Curve.png 1345w, https:\/\/deep-space-astronomy.ch\/wp-content\/uploads\/2025\/04\/Antlia-SII-3nm-Pro-Curve-300x171.png 300w, https:\/\/deep-space-astronomy.ch\/wp-content\/uploads\/2025\/04\/Antlia-SII-3nm-Pro-Curve-1024x585.png 1024w, https:\/\/deep-space-astronomy.ch\/wp-content\/uploads\/2025\/04\/Antlia-SII-3nm-Pro-Curve-768x439.png 768w, https:\/\/deep-space-astronomy.ch\/wp-content\/uploads\/2025\/04\/Antlia-SII-3nm-Pro-Curve-18x10.png 18w, https:\/\/deep-space-astronomy.ch\/wp-content\/uploads\/2025\/04\/Antlia-SII-3nm-Pro-Curve-600x343.png 600w\" sizes=\"(max-width: 1345px) 100vw, 1345px\" \/><\/div>\n<h3>Mounting ring<\/h3>\n<ul>\n<li>1.25'' (M28.5\u00d70.6), 2'' (M48x0.75)<\/li>\n<li>Ultra-thin cell for reduced vignetting<\/li>\n<li>Black anodized finish, unalterable laser engraving<\/li>\n<\/ul>\n<h3>Available sizes<\/h3>\n<ul>\n<li>Mounted: 1.25\u2033, 2\u2033<\/li>\n<li>Unmounted: \u00d831mm, \u00d836mm, \u00d850mm, square 50x50mm<\/li>\n<\/ul>\n<h3>Not recommended for :<\/h3>\n<ul>\n<li>Solar observation<\/li>\n<li>Visual observation at night<\/li>\n<\/ul>\n<h3>Warning:<\/h3>\n<p style=\"color: red;\"><strong>NEVER LOOK AT THE SUN WITH THIS FILTER.<\/strong> Serious eye damage may occur.<\/p>","protected":false},"excerpt":{"rendered":"<p>Filtre SII Antlia 3nm Pro Le filtre Antlia SII 3nm Pro optimise la largeur \u00e0 mi-hauteur (FWHM) \u00e0 3nm. En r\u00e9duisant la bande passante, ce filtre am\u00e9liore le contraste des cibles \u00e0 \u00e9mission en diminuant le signal parasite du fond de ciel. Il est con\u00e7u pour offrir une transmission de 88% \u00e0 la raie de [&hellip;]<\/p>\n","protected":false},"featured_media":7049,"comment_status":"open","ping_status":"closed","template":"","meta":[],"product_brand":[791],"product_cat":[780,833],"product_tag":[],"class_list":{"0":"post-7031","1":"product","2":"type-product","3":"status-publish","4":"has-post-thumbnail","6":"product_brand-antlia","7":"product_cat-filtres-bande-etroite","8":"product_cat-en-stock","10":"first","11":"instock","12":"taxable","13":"shipping-taxable","14":"purchasable","15":"product-type-variable"},"_links":{"self":[{"href":"https:\/\/deep-space-astronomy.ch\/en\/wp-json\/wp\/v2\/product\/7031","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=7031"}],"wp:featuredmedia":[{"embeddable":true,"href":"https:\/\/deep-space-astronomy.ch\/en\/wp-json\/wp\/v2\/media\/7049"}],"wp:attachment":[{"href":"https:\/\/deep-space-astronomy.ch\/en\/wp-json\/wp\/v2\/media?parent=7031"}],"wp:term":[{"taxonomy":"product_brand","embeddable":true,"href":"https:\/\/deep-space-astronomy.ch\/en\/wp-json\/wp\/v2\/product_brand?post=7031"},{"taxonomy":"product_cat","embeddable":true,"href":"https:\/\/deep-space-astronomy.ch\/en\/wp-json\/wp\/v2\/product_cat?post=7031"},{"taxonomy":"product_tag","embeddable":true,"href":"https:\/\/deep-space-astronomy.ch\/en\/wp-json\/wp\/v2\/product_tag?post=7031"}],"curies":[{"name":"wp","href":"https:\/\/api.w.org\/{rel}","templated":true}]}}