{"id":29093,"date":"2025-09-20T20:14:25","date_gmt":"2025-09-20T18:14:25","guid":{"rendered":"https:\/\/www.telescoop.nl\/?post_type=product&#038;p=29093"},"modified":"2026-03-20T12:58:34","modified_gmt":"2026-03-20T11:58:34","slug":"optolong-sii-filter-2-inch","status":"publish","type":"product","link":"https:\/\/www.telescoop.nl\/en\/optolong-sii-filter-2-inch\/","title":{"rendered":"Optolong SII Filter 2 inch"},"content":{"rendered":"<p class=\"wp-block-paragraph\">Optolong Filters SII Filter 2\u2033 is a high quality narrowband filter that passes only the sulfur-II (SII) emission line around 672 nm. This makes the filter an essential part of a complete narrowband set (Ha, OIII and SII) for astrophotography. By almost completely blocking unwanted wavelengths and artificial light, the sky background becomes considerably darker and fine details in emission nebulae become more apparent.<\/p>\n\n\n\n<p class=\"wp-block-paragraph\">The filter is particularly suitable for capturing emission nebulae such as the Crab Nebula, the Rosette Nebula and the Veil Nebula. In combination with H-alpha and OIII filters, classic Hubble palette recordings can be made (SII-Ha-OIII), showing nebular structures in color and detail.<\/p>\n\n\n\n<p class=\"wp-block-paragraph\">The optical glass features multiple anti-reflective coatings, minimizing reflections and halos. The sturdy 2\u2033 aluminum mount makes the filter compatible with filter wheels, 2\u2033 adapters and astrophotography setups with large sensors. This provides maximum flexibility for both amateur and semi-professional astrophotography.<\/p>\n\n\n\n<p class=\"wp-block-paragraph\"><strong>Observation goals<\/strong><br>The Optolong SII filter is ideal for astrophotographers who want to capture emission nebulae in narrowband technique. It is mainly used with monochrome cameras and long exposure times, but can also be applied with modified DSLRs. For visual use, this filter is not suitable because the narrow bandwidth does not allow enough light through for the human eye.<\/p>\n\n\n\n<p class=\"wp-block-paragraph\"><strong>Specifications<\/strong><\/p>\n\n\n\n<ul class=\"wp-block-list\">\n<li>Type: SII narrowband filter<\/li>\n\n\n\n<li>Wavelength: 672 nm (sulfur-II emission line)<\/li>\n\n\n\n<li>Diameter: 2\u2033 mount<\/li>\n\n\n\n<li>Material: Optical glass with multiple anti-reflection coating<\/li>\n\n\n\n<li>Mount: Aluminum<\/li>\n\n\n\n<li>Application:\n<ul class=\"wp-block-list\">\n<li>\u2713 Astrophotography of emission nebulae<\/li>\n\n\n\n<li>\u2713 Narrowband images combined with Ha and OIII<\/li>\n\n\n\n<li>\u2713 Ideal for Hubble palette (SII-Ha-OIII)<\/li>\n\n\n\n<li>\u2717 Not suitable for visual use<\/li>\n<\/ul>\n<\/li>\n<\/ul>","protected":false},"excerpt":{"rendered":"<article class=\"w-full text-token-text-primary focus-visible:outline-2 focus-visible:outline-offset-[-4px]\" dir=\"auto\" data-testid=\"conversation-turn-35\" data-scroll-anchor=\"true\">\n<div class=\"text-base my-auto mx-auto py-[18px] px-6\">\n<div class=\"mx-auto flex flex-1 text-base gap-4 md:gap-5 lg:gap-6 md:max-w-3xl lg:max-w-[40rem] xl:max-w-[48rem]\">\n<div class=\"group\/conversation-turn relative flex w-full min-w-0 flex-col agent-turn @xs\/thread:px-0 @sm\/thread:px-1.5 @md\/thread:px-4\">\n<div class=\"flex-col gap-1 md:gap-3\">\n<div class=\"flex max-w-full flex-col flex-grow\">\n<div class=\"min-h-8 text-message relative flex w-full flex-col items-end gap-2 whitespace-normal break-words text-start [.text-message+&amp;]:mt-5\" dir=\"auto\" data-message-author-role=\"assistant\" data-message-id=\"28a009d2-3136-4224-8ee5-30c9a1a2ece5\" data-message-model-slug=\"gpt-4o\">\n<div class=\"flex w-full flex-col gap-1 empty:hidden first:pt-[3px]\">\n<div class=\"markdown prose w-full break-words dark:prose-invert dark\">\n<p data-start=\"352\" data-end=\"808\">\u00a0<\/p>\n<p data-start=\"142\" data-end=\"350\">Optolong Filters SII Filter 2&#8243; wordt geleverd met aluminium vatting en smalle doorlaat rond 672 nm \u2013 gespecialiseerd smalbandfilter voor emissienevels en narrowband-astrofotografie.<\/p>\n<\/div>\n<\/div>\n<\/div>\n<\/div>\n<\/div>\n<\/div>\n<\/div>\n<\/div>\n<\/article>\n","protected":false},"featured_media":29104,"comment_status":"open","ping_status":"closed","template":"","meta":{"_acf_changed":false},"product_brand":[1548],"product_cat":[3138,587,588,56],"product_tag":[],"class_list":["post-29093","product","type-product","status-publish","has-post-thumbnail","product_brand-optolong","product_cat-imaging-filters-smalband-en-lrgb","product_cat-camera-accessoires","product_cat-filters","product_cat-telescoop-accessoires","product_shipping_class-licht","first","instock","taxable","shipping-taxable","purchasable","product-type-simple"],"bundled_by":[],"bundle_stock_status":"instock","bundle_stock_quantity":null,"bundle_virtual":false,"bundle_layout":"","bundle_add_to_cart_form_location":"","bundle_editable_in_cart":false,"bundle_sold_individually_context":"","bundle_item_grouping":"","bundle_min_size":"","bundle_max_size":"","bundle_price":[],"bundled_items":[],"bundle_sell_ids":[],"acf":[],"jetpack_sharing_enabled":true,"jetpack-related-posts":[{"id":29111,"url":"https:\/\/www.telescoop.nl\/en\/optolong-pro-veil-sii-filter-3nm-2-inch\/","url_meta":{"origin":29093,"position":0},"title":"Optolong Pro Veil SII Filter 3nm 2 inch","author":"","date":"22-09-2025","format":false,"excerpt":"\u00a0 The Optolong Filters Pro Veil SII 3nm 2'' comes with a precisely tuned narrowband filter for detailed imaging of emission nebulae.","rel":"","context":"Similar post","block_context":{"text":"Similar post","link":""},"img":{"alt_text":"Optolong Filters Pro Veil SII 3nm 2''","src":"https:\/\/i0.wp.com\/www.telescoop.nl\/wp-content\/uploads\/2025\/09\/Optolong-Filters-Pro-Veil-SII-3nm-2-.jpg?resize=350%2C200&ssl=1","width":350,"height":200,"srcset":"https:\/\/i0.wp.com\/www.telescoop.nl\/wp-content\/uploads\/2025\/09\/Optolong-Filters-Pro-Veil-SII-3nm-2-.jpg?resize=350%2C200&ssl=1 1x, https:\/\/i0.wp.com\/www.telescoop.nl\/wp-content\/uploads\/2025\/09\/Optolong-Filters-Pro-Veil-SII-3nm-2-.jpg?resize=525%2C300&ssl=1 1.5x, https:\/\/i0.wp.com\/www.telescoop.nl\/wp-content\/uploads\/2025\/09\/Optolong-Filters-Pro-Veil-SII-3nm-2-.jpg?resize=700%2C400&ssl=1 2x, https:\/\/i0.wp.com\/www.telescoop.nl\/wp-content\/uploads\/2025\/09\/Optolong-Filters-Pro-Veil-SII-3nm-2-.jpg?resize=1050%2C600&ssl=1 3x, https:\/\/i0.wp.com\/www.telescoop.nl\/wp-content\/uploads\/2025\/09\/Optolong-Filters-Pro-Veil-SII-3nm-2-.jpg?resize=1400%2C800&ssl=1 4x"},"classes":[]},{"id":29117,"url":"https:\/\/www.telescoop.nl\/en\/optolong-sho-filter-kit-3nm-2-inch\/","url_meta":{"origin":29093,"position":1},"title":"Optolong SHO Filter Kit 3nm 2 inch","author":"","date":"22-09-2025","format":false,"excerpt":"\u00a0 Optolong Filters SHO 3nm 2\" comes with a set of high-quality narrowband filters (H-alpha, OIII, and SII) for colorful nebula shots in the Hubble palette.","rel":"","context":"Similar post","block_context":{"text":"Similar post","link":""},"img":{"alt_text":"Optolong Filters SHO 3nm 2\"","src":"https:\/\/i0.wp.com\/www.telescoop.nl\/wp-content\/uploads\/2025\/09\/Optolong-Filters-SHO-3nm-2-.jpg?resize=350%2C200&ssl=1","width":350,"height":200,"srcset":"https:\/\/i0.wp.com\/www.telescoop.nl\/wp-content\/uploads\/2025\/09\/Optolong-Filters-SHO-3nm-2-.jpg?resize=350%2C200&ssl=1 1x, https:\/\/i0.wp.com\/www.telescoop.nl\/wp-content\/uploads\/2025\/09\/Optolong-Filters-SHO-3nm-2-.jpg?resize=525%2C300&ssl=1 1.5x, https:\/\/i0.wp.com\/www.telescoop.nl\/wp-content\/uploads\/2025\/09\/Optolong-Filters-SHO-3nm-2-.jpg?resize=700%2C400&ssl=1 2x, https:\/\/i0.wp.com\/www.telescoop.nl\/wp-content\/uploads\/2025\/09\/Optolong-Filters-SHO-3nm-2-.jpg?resize=1050%2C600&ssl=1 3x, https:\/\/i0.wp.com\/www.telescoop.nl\/wp-content\/uploads\/2025\/09\/Optolong-Filters-SHO-3nm-2-.jpg?resize=1400%2C800&ssl=1 4x"},"classes":[]},{"id":29141,"url":"https:\/\/www.telescoop.nl\/en\/optolong-sho-filter-kit-3nm-36mm\/","url_meta":{"origin":29093,"position":2},"title":"Optolong SHO Filter Kit 3nm 36mm","author":"","date":"22-09-2025","format":false,"excerpt":"\u00a0 Optolong Filters SHO 3nm 36mm comes with a complete set of narrowband filters (H-alpha, OIII and SII) for astrophotography in the Hubble palette.","rel":"","context":"Similar post","block_context":{"text":"Similar post","link":""},"img":{"alt_text":"Optolong Filters SHO 3nm 36mm","src":"https:\/\/i0.wp.com\/www.telescoop.nl\/wp-content\/uploads\/2025\/09\/Optolong-Filters-SHO-3nm-36mm.jpg?resize=350%2C200&ssl=1","width":350,"height":200,"srcset":"https:\/\/i0.wp.com\/www.telescoop.nl\/wp-content\/uploads\/2025\/09\/Optolong-Filters-SHO-3nm-36mm.jpg?resize=350%2C200&ssl=1 1x, https:\/\/i0.wp.com\/www.telescoop.nl\/wp-content\/uploads\/2025\/09\/Optolong-Filters-SHO-3nm-36mm.jpg?resize=525%2C300&ssl=1 1.5x, https:\/\/i0.wp.com\/www.telescoop.nl\/wp-content\/uploads\/2025\/09\/Optolong-Filters-SHO-3nm-36mm.jpg?resize=700%2C400&ssl=1 2x, https:\/\/i0.wp.com\/www.telescoop.nl\/wp-content\/uploads\/2025\/09\/Optolong-Filters-SHO-3nm-36mm.jpg?resize=1050%2C600&ssl=1 3x, https:\/\/i0.wp.com\/www.telescoop.nl\/wp-content\/uploads\/2025\/09\/Optolong-Filters-SHO-3nm-36mm.jpg?resize=1400%2C800&ssl=1 4x"},"classes":[]},{"id":29165,"url":"https:\/\/www.telescoop.nl\/en\/optolong-sho-filter-kit-1-25-inch\/","url_meta":{"origin":29093,"position":3},"title":"Optolong SHO Filter Kit 1.25 inch","author":"","date":"22-09-2025","format":false,"excerpt":"\u00a0 Optolong Filters SHO Filter Kit 1,25\" wordt geleverd met drie smalbandfilters (H-alpha, OIII en SII) voor kleurrijke astrofotografie in het Hubble-palet.","rel":"","context":"Similar post","block_context":{"text":"Similar post","link":""},"img":{"alt_text":"Optolong Filters SHO Filter Kit 7nm 2\"","src":"https:\/\/i0.wp.com\/www.telescoop.nl\/wp-content\/uploads\/2025\/09\/Optolong-Filters-SHO-Filter-Kit-7nm-2-.jpg?resize=350%2C200&ssl=1","width":350,"height":200,"srcset":"https:\/\/i0.wp.com\/www.telescoop.nl\/wp-content\/uploads\/2025\/09\/Optolong-Filters-SHO-Filter-Kit-7nm-2-.jpg?resize=350%2C200&ssl=1 1x, https:\/\/i0.wp.com\/www.telescoop.nl\/wp-content\/uploads\/2025\/09\/Optolong-Filters-SHO-Filter-Kit-7nm-2-.jpg?resize=525%2C300&ssl=1 1.5x, https:\/\/i0.wp.com\/www.telescoop.nl\/wp-content\/uploads\/2025\/09\/Optolong-Filters-SHO-Filter-Kit-7nm-2-.jpg?resize=700%2C400&ssl=1 2x, https:\/\/i0.wp.com\/www.telescoop.nl\/wp-content\/uploads\/2025\/09\/Optolong-Filters-SHO-Filter-Kit-7nm-2-.jpg?resize=1050%2C600&ssl=1 3x, https:\/\/i0.wp.com\/www.telescoop.nl\/wp-content\/uploads\/2025\/09\/Optolong-Filters-SHO-Filter-Kit-7nm-2-.jpg?resize=1400%2C800&ssl=1 4x"},"classes":[]},{"id":29150,"url":"https:\/\/www.telescoop.nl\/en\/optolong-sho-filter-kit-7nm-2-inch\/","url_meta":{"origin":29093,"position":4},"title":"Optolong SHO Filter Kit 7nm 2 inch","author":"","date":"22-09-2025","format":false,"excerpt":"\u00a0 Optolong Filters SHO Filter Kit 7nm 2\" wordt geleverd met een complete set smalbandfilters (H-alpha, OIII en SII) voor creatieve nevelopnames in SHO-kleuren.","rel":"","context":"Similar post","block_context":{"text":"Similar post","link":""},"img":{"alt_text":"Optolong Filters SHO Filter Kit 7nm 2\"","src":"https:\/\/i0.wp.com\/www.telescoop.nl\/wp-content\/uploads\/2025\/09\/Optolong-Filters-SHO-Filter-Kit-7nm-2-.jpg?resize=350%2C200&ssl=1","width":350,"height":200,"srcset":"https:\/\/i0.wp.com\/www.telescoop.nl\/wp-content\/uploads\/2025\/09\/Optolong-Filters-SHO-Filter-Kit-7nm-2-.jpg?resize=350%2C200&ssl=1 1x, https:\/\/i0.wp.com\/www.telescoop.nl\/wp-content\/uploads\/2025\/09\/Optolong-Filters-SHO-Filter-Kit-7nm-2-.jpg?resize=525%2C300&ssl=1 1.5x, https:\/\/i0.wp.com\/www.telescoop.nl\/wp-content\/uploads\/2025\/09\/Optolong-Filters-SHO-Filter-Kit-7nm-2-.jpg?resize=700%2C400&ssl=1 2x, https:\/\/i0.wp.com\/www.telescoop.nl\/wp-content\/uploads\/2025\/09\/Optolong-Filters-SHO-Filter-Kit-7nm-2-.jpg?resize=1050%2C600&ssl=1 3x, https:\/\/i0.wp.com\/www.telescoop.nl\/wp-content\/uploads\/2025\/09\/Optolong-Filters-SHO-Filter-Kit-7nm-2-.jpg?resize=1400%2C800&ssl=1 4x"},"classes":[]},{"id":29063,"url":"https:\/\/www.telescoop.nl\/en\/optolong-oiii-filter-3nm-2-inch\/","url_meta":{"origin":29093,"position":5},"title":"Optolong OIII Filter 3nm 2 inch","author":"","date":"20-09-2025","format":false,"excerpt":"\u00a0 Optolong Filters OIII 3nm 2\" comes with an aluminum mounting and an ultra-narrow passband of 3nm \u2013 a high-end narrowband filter for extremely high-contrast nebula astrophotography.","rel":"","context":"Similar post","block_context":{"text":"Similar post","link":""},"img":{"alt_text":"Optolong Filters OIII 3nm 2\"","src":"https:\/\/i0.wp.com\/www.telescoop.nl\/wp-content\/uploads\/2025\/09\/Optolong-Filters-OIII-3nm-2-.jpg?resize=350%2C200&ssl=1","width":350,"height":200,"srcset":"https:\/\/i0.wp.com\/www.telescoop.nl\/wp-content\/uploads\/2025\/09\/Optolong-Filters-OIII-3nm-2-.jpg?resize=350%2C200&ssl=1 1x, https:\/\/i0.wp.com\/www.telescoop.nl\/wp-content\/uploads\/2025\/09\/Optolong-Filters-OIII-3nm-2-.jpg?resize=525%2C300&ssl=1 1.5x, https:\/\/i0.wp.com\/www.telescoop.nl\/wp-content\/uploads\/2025\/09\/Optolong-Filters-OIII-3nm-2-.jpg?resize=700%2C400&ssl=1 2x, https:\/\/i0.wp.com\/www.telescoop.nl\/wp-content\/uploads\/2025\/09\/Optolong-Filters-OIII-3nm-2-.jpg?resize=1050%2C600&ssl=1 3x, https:\/\/i0.wp.com\/www.telescoop.nl\/wp-content\/uploads\/2025\/09\/Optolong-Filters-OIII-3nm-2-.jpg?resize=1400%2C800&ssl=1 4x"},"classes":[]}],"_links":{"self":[{"href":"https:\/\/www.telescoop.nl\/en\/wp-json\/wp\/v2\/product\/29093","targetHints":{"allow":["GET"]}}],"collection":[{"href":"https:\/\/www.telescoop.nl\/en\/wp-json\/wp\/v2\/product"}],"about":[{"href":"https:\/\/www.telescoop.nl\/en\/wp-json\/wp\/v2\/types\/product"}],"replies":[{"embeddable":true,"href":"https:\/\/www.telescoop.nl\/en\/wp-json\/wp\/v2\/comments?post=29093"}],"wp:featuredmedia":[{"embeddable":true,"href":"https:\/\/www.telescoop.nl\/en\/wp-json\/wp\/v2\/media\/29104"}],"wp:attachment":[{"href":"https:\/\/www.telescoop.nl\/en\/wp-json\/wp\/v2\/media?parent=29093"}],"wp:term":[{"taxonomy":"product_brand","embeddable":true,"href":"https:\/\/www.telescoop.nl\/en\/wp-json\/wp\/v2\/product_brand?post=29093"},{"taxonomy":"product_cat","embeddable":true,"href":"https:\/\/www.telescoop.nl\/en\/wp-json\/wp\/v2\/product_cat?post=29093"},{"taxonomy":"product_tag","embeddable":true,"href":"https:\/\/www.telescoop.nl\/en\/wp-json\/wp\/v2\/product_tag?post=29093"}],"curies":[{"name":"wp","href":"https:\/\/api.w.org\/{rel}","templated":true}]}}