{"id":113184,"date":"2026-10-09T16:54:14","date_gmt":"2026-10-09T14:54:14","guid":{"rendered":"https:\/\/www.telescoop.nl\/?post_type=product&p=113184"},"modified":"2026-10-13T11:14:23","modified_gmt":"2026-10-13T09:14:23","slug":"e-200n150-legacy-prefilter-for-h-alpha-solar-warning-daystar","status":"publish","type":"product","link":"https:\/\/www.telescoop.nl\/en\/erf-voorfilter-e-200n150-voor-h-alpha-zonnewaarneming-daystar\/","title":{"rendered":"ERF-prefilter E-200N150 for H-alpha solar monitoring | DayStar"},"content":{"rendered":"

A DayStar Quark or other H-alpha filter on a telescope with a large aperture will have to process a lot of heat without a pre-filter. Therefore, you should place the DayStar ERF E-200N150 in front of the telescope aperture. The filter blocks most of the ultraviolet and infrared light and lets through mostly red light, so the H-alpha filter stays protected at the rear.<\/p>\n\n\n\n

The filter fits either the tube or the dew cap, provided the fitting matches the outer diameter. All sizes and other filters for the sun are available from our sunwatch filters<\/a>.<\/p>\n\n\n\n

Measure the outside diameter in advance and contact us if in doubt. Never look at the sun with an ERF alone. Use the filter only as part of a complete H-alpha setup, as intended. For smaller openings, it is sometimes a UV\/IR blocking filter in 2 inch<\/a> an option, but first get advice about it, because it depends on the opening and the type of telescope.<\/p>","protected":false},"excerpt":{"rendered":"

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.<\/p>","protected":false},"featured_media":113183,"comment_status":"open","ping_status":"closed","template":"","meta":{"_acf_changed":false},"product_brand":[3282],"product_cat":[56,3178],"product_tag":[],"class_list":["post-113184","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":113184,"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":113156,"url":"https:\/\/www.telescoop.nl\/en\/erf-voorfilter-e-110n75-voor-h-alpha-zonnewaarneming-daystar\/","url_meta":{"origin":113184,"position":1},"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":113157,"url":"https:\/\/www.telescoop.nl\/en\/erf-voorfilter-e-120n80-voor-h-alpha-zonnewaarneming-daystar\/","url_meta":{"origin":113184,"position":2},"title":"ERF-prefilter E-120N80 for H-alpha solar monitoring | DayStar","author":"Info telescoop","date":"09-10-2026","format":false,"excerpt":"DayStar's E-120N80 pre-filter for H-alpha solar observation, which prevents heat, UV and infrared from entering your telescope before it opens.","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":113159,"url":"https:\/\/www.telescoop.nl\/en\/erf-voorfilter-e-130n100-voor-h-alpha-zonnewaarneming-daystar\/","url_meta":{"origin":113184,"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":113161,"url":"https:\/\/www.telescoop.nl\/en\/erf-voorfilter-e-150n100-voor-h-alpha-zonnewaarneming-daystar\/","url_meta":{"origin":113184,"position":4},"title":"ERF-prefilter E-150N100 for H-alpha solar monitoring | DayStar","author":"Info telescoop","date":"09-10-2026","format":false,"excerpt":"DayStar pre-filter in size E-150N100 that blocks UV and infrared outside your telescope, as the first step of an 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":113166,"url":"https:\/\/www.telescoop.nl\/en\/erf-voorfilter-e-325f90-voor-h-alpha-zonnewaarneming-daystar\/","url_meta":{"origin":113184,"position":5},"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 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