{"id":113161,"date":"2026-10-09T16:54:09","date_gmt":"2026-10-09T14:54:09","guid":{"rendered":"https:\/\/www.telescoop.nl\/?post_type=product&#038;p=113161"},"modified":"2026-10-13T11:14:23","modified_gmt":"2026-10-13T09:14:23","slug":"legacy-pre-filter-e-150n100-for-h-alpha-solar-warning-daystar","status":"publish","type":"product","link":"https:\/\/www.telescoop.nl\/en\/erf-voorfilter-e-150n100-voor-h-alpha-zonnewaarneming-daystar\/","title":{"rendered":"ERF-prefilter E-150N100 for H-alpha solar monitoring | DayStar"},"content":{"rendered":"<p class=\"wp-block-paragraph\">Without a pre-filter, too much heat ends up in the narrow H-alpha filter at the rear with larger apertures. The DayStar ERF E-150N100 for the aperture solves this problem. The filter blocks ultraviolet and infrared light and allows the red light to pass through, which is what the H-alpha filter works with.<\/p>\n\n\n\n<p class=\"wp-block-paragraph\">Which ERF you need depends on the opening and the outer diameter of your telescope. You can find the other sizes and separate filters at our website. <a href=\"https:\/\/www.telescoop.nl\/en\/telescope-accessories\/sun-filters\/\">solar filters for telescopes<\/a>. If you are unsure about choosing between two sizes, please compare them. <a href=\"https:\/\/www.telescoop.nl\/en\/e-130n100-legacy-prefilter-for-h-alpha-sun-warning-daystar\/\">the ERF pre-filter E-130N100<\/a>.<\/p>\n\n\n\n<p class=\"wp-block-paragraph\">Measure the outer diameter of your tube or watering can and compare it with the specified size of the container. Then, don't aim your telescope at the sun by chance, but use <a href=\"https:\/\/www.telescoop.nl\/en\/universal-solar-finder-to-focus-your-telescope-on-the-sun-daystar\/\">a solar viewfinder with projection<\/a>, So that you never have to look through an unfiltered viewfinder. An ERF itself is not a solar filter to use for viewing, so never look at the sun without the full filter setup.<\/p>","protected":false},"excerpt":{"rendered":"<p>DayStar pre-filter in size E-150N100 that blocks UV and infrared outside your telescope, as the first step of an H-alpha setup.<\/p>","protected":false},"featured_media":113155,"comment_status":"open","ping_status":"closed","template":"","meta":{"_acf_changed":false},"product_brand":[3282],"product_cat":[56,3178],"product_tag":[],"class_list":["post-113161","product","type-product","status-publish","has-post-thumbnail","product_brand-daystar","product_cat-telescoop-accessoires","product_cat-zonnefilters","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":113158,"url":"https:\/\/www.telescoop.nl\/en\/erf-voorfilter-e-120n100-voor-h-alpha-zonnewaarneming-daystar\/","url_meta":{"origin":113161,"position":0},"title":"ERF pre-filter E-120N100 for H-alpha solar monitoring | DayStar","author":"Info telescoop","date":"09-10-2026","format":false,"excerpt":"Energy rejection pre-filter E-120N100 from DayStar that protects your H-alpha filter and telescope from the heat, UV and infrared of the sun.","rel":"","context":"Similar post","block_context":{"text":"Similar post","link":""},"img":{"alt_text":"","src":"https:\/\/i0.wp.com\/www.telescoop.nl\/wp-content\/uploads\/2026\/10\/12827_1.jpg?resize=350%2C200&ssl=1","width":350,"height":200,"srcset":"https:\/\/i0.wp.com\/www.telescoop.nl\/wp-content\/uploads\/2026\/10\/12827_1.jpg?resize=350%2C200&ssl=1 1x, https:\/\/i0.wp.com\/www.telescoop.nl\/wp-content\/uploads\/2026\/10\/12827_1.jpg?resize=525%2C300&ssl=1 1.5x"},"classes":[]},{"id":113166,"url":"https:\/\/www.telescoop.nl\/en\/erf-voorfilter-e-325f90-voor-h-alpha-zonnewaarneming-daystar\/","url_meta":{"origin":113161,"position":1},"title":"ERF pre-filter E-325F90 for H-alpha solar monitoring | DayStar","author":"Info telescoop","date":"09-10-2026","format":false,"excerpt":"DayStar ERF pre-filter in size E-325F90 for opening your telescope, which keeps heat, UV and infrared out of your H-alpha setup.","rel":"","context":"Similar post","block_context":{"text":"Similar post","link":""},"img":{"alt_text":"","src":"https:\/\/i0.wp.com\/www.telescoop.nl\/wp-content\/uploads\/2026\/10\/12827_1.jpg?resize=350%2C200&ssl=1","width":350,"height":200,"srcset":"https:\/\/i0.wp.com\/www.telescoop.nl\/wp-content\/uploads\/2026\/10\/12827_1.jpg?resize=350%2C200&ssl=1 1x, https:\/\/i0.wp.com\/www.telescoop.nl\/wp-content\/uploads\/2026\/10\/12827_1.jpg?resize=525%2C300&ssl=1 1.5x"},"classes":[]},{"id":113184,"url":"https:\/\/www.telescoop.nl\/en\/erf-voorfilter-e-200n150-voor-h-alpha-zonnewaarneming-daystar\/","url_meta":{"origin":113161,"position":2},"title":"ERF-prefilter E-200N150 for H-alpha solar monitoring | DayStar","author":"Info telescoop","date":"09-10-2026","format":false,"excerpt":"ERF for the front of your telescope in size E-200N150. It blocks UV and infrared light, so your H-alpha filter doesn't get too hot.","rel":"","context":"Similar post","block_context":{"text":"Similar post","link":""},"img":{"alt_text":"","src":"https:\/\/i0.wp.com\/www.telescoop.nl\/wp-content\/uploads\/2026\/10\/74437_1.jpg?resize=350%2C200&ssl=1","width":350,"height":200,"srcset":"https:\/\/i0.wp.com\/www.telescoop.nl\/wp-content\/uploads\/2026\/10\/74437_1.jpg?resize=350%2C200&ssl=1 1x, https:\/\/i0.wp.com\/www.telescoop.nl\/wp-content\/uploads\/2026\/10\/74437_1.jpg?resize=525%2C300&ssl=1 1.5x"},"classes":[]},{"id":113159,"url":"https:\/\/www.telescoop.nl\/en\/erf-voorfilter-e-130n100-voor-h-alpha-zonnewaarneming-daystar\/","url_meta":{"origin":113161,"position":3},"title":"ERF pre-filter E-130N100 for H-alpha solar monitoring | DayStar","author":"Info telescoop","date":"09-10-2026","format":false,"excerpt":"ERF pre-filter in size E-130N100 that comes before your telescope and prevents heat, UV and infrared in an H-alpha configuration.","rel":"","context":"Similar post","block_context":{"text":"Similar post","link":""},"img":{"alt_text":"","src":"https:\/\/i0.wp.com\/www.telescoop.nl\/wp-content\/uploads\/2026\/10\/12827_1.jpg?resize=350%2C200&ssl=1","width":350,"height":200,"srcset":"https:\/\/i0.wp.com\/www.telescoop.nl\/wp-content\/uploads\/2026\/10\/12827_1.jpg?resize=350%2C200&ssl=1 1x, https:\/\/i0.wp.com\/www.telescoop.nl\/wp-content\/uploads\/2026\/10\/12827_1.jpg?resize=525%2C300&ssl=1 1.5x"},"classes":[]},{"id":113156,"url":"https:\/\/www.telescoop.nl\/en\/erf-voorfilter-e-110n75-voor-h-alpha-zonnewaarneming-daystar\/","url_meta":{"origin":113161,"position":4},"title":"ERF pre-filter E-110N75 for H-alpha solar monitoring | DayStar","author":"Info telescoop","date":"09-10-2026","format":false,"excerpt":"Energy rejection pre-filter E-110N75 from DayStar for opening your telescope, which prevents UV and infrared radiation during H-alpha observations.","rel":"","context":"Similar post","block_context":{"text":"Similar post","link":""},"img":{"alt_text":"","src":"https:\/\/i0.wp.com\/www.telescoop.nl\/wp-content\/uploads\/2026\/10\/12827_1.jpg?resize=350%2C200&ssl=1","width":350,"height":200,"srcset":"https:\/\/i0.wp.com\/www.telescoop.nl\/wp-content\/uploads\/2026\/10\/12827_1.jpg?resize=350%2C200&ssl=1 1x, https:\/\/i0.wp.com\/www.telescoop.nl\/wp-content\/uploads\/2026\/10\/12827_1.jpg?resize=525%2C300&ssl=1 1.5x"},"classes":[]},{"id":113163,"url":"https:\/\/www.telescoop.nl\/en\/erf-voorfilter-e-180n130-voor-h-alpha-zonnewaarneming-daystar\/","url_meta":{"origin":113161,"position":5},"title":"ERF pre-filter E-180N130 for H-alpha solar monitoring | DayStar","author":"Info telescoop","date":"09-10-2026","format":false,"excerpt":"Pre-filter in size E-180N130 that keeps heat, UV and infrared out of your telescope when observing the Sun in H-alpha.","rel":"","context":"Similar post","block_context":{"text":"Similar post","link":""},"img":{"alt_text":"","src":"https:\/\/i0.wp.com\/www.telescoop.nl\/wp-content\/uploads\/2026\/10\/12827_1.jpg?resize=350%2C200&ssl=1","width":350,"height":200,"srcset":"https:\/\/i0.wp.com\/www.telescoop.nl\/wp-content\/uploads\/2026\/10\/12827_1.jpg?resize=350%2C200&ssl=1 1x, https:\/\/i0.wp.com\/www.telescoop.nl\/wp-content\/uploads\/2026\/10\/12827_1.jpg?resize=525%2C300&ssl=1 1.5x"},"classes":[]}],"_links":{"self":[{"href":"https:\/\/www.telescoop.nl\/en\/wp-json\/wp\/v2\/product\/113161","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=113161"}],"wp:featuredmedia":[{"embeddable":true,"href":"https:\/\/www.telescoop.nl\/en\/wp-json\/wp\/v2\/media\/113155"}],"wp:attachment":[{"href":"https:\/\/www.telescoop.nl\/en\/wp-json\/wp\/v2\/media?parent=113161"}],"wp:term":[{"taxonomy":"product_brand","embeddable":true,"href":"https:\/\/www.telescoop.nl\/en\/wp-json\/wp\/v2\/product_brand?post=113161"},{"taxonomy":"product_cat","embeddable":true,"href":"https:\/\/www.telescoop.nl\/en\/wp-json\/wp\/v2\/product_cat?post=113161"},{"taxonomy":"product_tag","embeddable":true,"href":"https:\/\/www.telescoop.nl\/en\/wp-json\/wp\/v2\/product_tag?post=113161"}],"curies":[{"name":"wp","href":"https:\/\/api.w.org\/{rel}","templated":true}]}}