{"id":109399,"date":"2026-07-16T16:56:22","date_gmt":"2026-07-16T14:56:22","guid":{"rendered":"https:\/\/www.telescoop.nl\/lunt-b1200d2-blockfilter-in-zenitspiegel-2-inch\/"},"modified":"2026-08-19T17:19:29","modified_gmt":"2026-08-19T15:19:29","slug":"lunt-b1200d2-blocking-filter-in-2-inch-zenith-mirror","status":"publish","type":"product","link":"https:\/\/www.telescoop.nl\/en\/lunt-b1200d2-blockfilter-in-zenitspiegel-2-inch\/","title":{"rendered":"Lunt B1200d2 Block Filter in 2-inch Diagonal Mirror"},"content":{"rendered":"<p class=\"wp-block-paragraph\">A <strong>blockfilter<\/strong> is not an accessory that you can buy: it is a <em>necessary part<\/em> of each H-alpha system. The etalon at the front allows the H-alpha line to pass through, as well as its harmonics. The blocking filter is located just before the eyepiece and removes all this remaining light. Without a blocking filter, the system is <strong>not safe<\/strong>.<\/p>\n\n\n\n<figure class=\"wp-block-image size-large\"><img decoding=\"async\" src=\"https:\/\/www.telescoop.nl\/wp-content\/uploads\/2026\/07\/Lunt-B1200d2-Blockfilter-in-Zenitspiegel-2-inch-1.jpg\" alt=\"Lunt B1200d2 Block Filter in 2-inch Diagonal Mirror\" title=\"\"><\/figure>\n\n\n\n<h3 class=\"wp-block-heading\">The number is the pass<\/h3>\n\n\n\n<p class=\"wp-block-paragraph\">B600, B1200, B1800, B3400: the number indicates the free passage in tenths of millimeters. A <strong>B1200 has a 12 mm passage.<\/strong>. The larger the aperture, the larger the portion of the field of view that <em>unobstructed and uniformly illuminated<\/em> and the longer the focal length you can use without vignetting.<\/p>\n\n\n\n<p class=\"wp-block-paragraph\">Rule of thumb: for <strong>visual use<\/strong> is a smaller block filter sufficient. For <strong>photography<\/strong> Your sensor size determines the choice. Small sensor: B1200 can. APS-C: B1800. Large sensor or full-frame: B3400.<\/p>\n\n\n\n<h3 class=\"wp-block-heading\">This execution: 12 mm in zenith mirror (2 inch)<\/h3>\n\n\n\n<p class=\"wp-block-paragraph\">Passage <strong>12 mm<\/strong>, suitable for telescopes <strong>to 1080 mm focal length<\/strong>. Execution: Zenith mirror (2 inch). At the eyepiece side 1.25 inch with T2 thread for camera connection.<\/p>\n\n\n\n<p class=\"wp-block-paragraph\">The commonly used medium size: excellent for visual perception and useful for photography with <strong>small sensors<\/strong>.<\/p>\n\n\n\n<p class=\"wp-block-paragraph\"><strong>Notice:<\/strong> This filter does not work independently. It is only usable in combination with a Lunt H-alpha telescope or filter system.<\/p>\n\n\n\n<h2 class=\"wp-block-heading\">Specifications<\/h2>\n\n\n\n<ul class=\"wp-block-list\">\n<li><strong>Passage<\/strong> 12 mm<\/li>\n\n\n\n<li><strong>Suitable for focal length:<\/strong> 1080 mm<\/li>\n\n\n\n<li><strong>Execution:<\/strong> Zenith mirror (2 inch)<\/li>\n\n\n\n<li><strong>Oculaira connection:<\/strong> 1.25 inches<\/li>\n\n\n\n<li><strong>Camera connection:<\/strong> T2 thread<\/li>\n\n\n\n<li><strong>Only usable with:<\/strong> Lunt H-alpha systems<\/li>\n\n\n\n<li><strong>Bresser Article Number:<\/strong> 0553010<\/li>\n<\/ul>\n\n\n\n<h2 class=\"wp-block-heading\">What you receive<\/h2>\n\n\n\n<ul class=\"wp-block-list\">\n<li>Blockfilter 12 in zenith mirror (2 inch)<\/li>\n\n\n\n<li>Manual<\/li>\n<\/ul>\n\n\n\n<h3 class=\"wp-block-heading\">Safety<\/h3>\n\n\n\n<p class=\"wp-block-paragraph\">Never look at the sun without the H-alpha etalon and blocking filter correctly installed. Use the instrument only as intended by Lunt and never disassemble it. Never leave a telescope pointed at the sun unattended.<\/p>\n\n\n\n<p class=\"wp-block-paragraph\">You can find more solar instruments and modules from this merk on the <a href=\"\/en\/brands\/lunt-solar-systems\/\">Lunt Solar Systems merk Page<\/a>.<\/p>","protected":false},"excerpt":{"rendered":"<p>Lunt blocking filter with 12 mm clear aperture, designed as a zenith mirror (2 inch). Suitable for telescopes up to 1080 mm focal length. Usable only with Lunt H-alpha systems.<\/p>","protected":false},"featured_media":109453,"comment_status":"open","ping_status":"closed","template":"","meta":{"_acf_changed":false},"product_brand":[2976],"product_cat":[3178],"product_tag":[],"class_list":["post-109399","product","type-product","status-publish","has-post-thumbnail","product_brand-lunt-solar-systems","product_cat-zonnefilters","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":111636,"url":"https:\/\/www.telescoop.nl\/en\/zwo-seestar-s50-pro\/","url_meta":{"origin":109399,"position":0},"title":"ZWO Seestar S50 Pro","author":"Info telescoop","date":"25-08-2026","format":false,"excerpt":"De ZWO Seestar S50 Pro is de opvolger van de Seestar S50: 50 mm quadruplet APO (260 mm, f\/5.2), twee 4K-sensoren van 8,3 MP, een groothoekcamera van 63 graden voor de Melkweg tot 8K, drie ingebouwde filters, 10.000 mAh accu (tot 9 uur) en 128 GB opslag. Vier opnamemodi voor\u2026","rel":"","context":"Similar post","block_context":{"text":"Similar post","link":""},"img":{"alt_text":"ZWO Seestar S50 Pro hero","src":"https:\/\/i0.wp.com\/www.telescoop.nl\/wp-content\/uploads\/2026\/08\/zwo-seestar-s50-pro.jpg?resize=350%2C200&ssl=1","width":350,"height":200,"srcset":"https:\/\/i0.wp.com\/www.telescoop.nl\/wp-content\/uploads\/2026\/08\/zwo-seestar-s50-pro.jpg?resize=350%2C200&ssl=1 1x, https:\/\/i0.wp.com\/www.telescoop.nl\/wp-content\/uploads\/2026\/08\/zwo-seestar-s50-pro.jpg?resize=525%2C300&ssl=1 1.5x, https:\/\/i0.wp.com\/www.telescoop.nl\/wp-content\/uploads\/2026\/08\/zwo-seestar-s50-pro.jpg?resize=700%2C400&ssl=1 2x"},"classes":[]}],"_links":{"self":[{"href":"https:\/\/www.telescoop.nl\/en\/wp-json\/wp\/v2\/product\/109399","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=109399"}],"wp:featuredmedia":[{"embeddable":true,"href":"https:\/\/www.telescoop.nl\/en\/wp-json\/wp\/v2\/media\/109453"}],"wp:attachment":[{"href":"https:\/\/www.telescoop.nl\/en\/wp-json\/wp\/v2\/media?parent=109399"}],"wp:term":[{"taxonomy":"product_brand","embeddable":true,"href":"https:\/\/www.telescoop.nl\/en\/wp-json\/wp\/v2\/product_brand?post=109399"},{"taxonomy":"product_cat","embeddable":true,"href":"https:\/\/www.telescoop.nl\/en\/wp-json\/wp\/v2\/product_cat?post=109399"},{"taxonomy":"product_tag","embeddable":true,"href":"https:\/\/www.telescoop.nl\/en\/wp-json\/wp\/v2\/product_tag?post=109399"}],"curies":[{"name":"wp","href":"https:\/\/api.w.org\/{rel}","templated":true}]}}