{"id":29180,"date":"2025-09-22T10:59:27","date_gmt":"2025-09-22T08:59:27","guid":{"rendered":"https:\/\/www.telescoop.nl\/?post_type=product&#038;p=29180"},"modified":"2026-03-20T13:00:46","modified_gmt":"2026-03-20T12:00:46","slug":"optolong-clear-focusing-filter-1-25-inches","status":"publish","type":"product","link":"https:\/\/www.telescoop.nl\/en\/optolong-clear-focusing-filter-1-25-inch\/","title":{"rendered":"Optolong Clear Focusing Filter 1.25 inches"},"content":{"rendered":"<p class=\"wp-block-paragraph\">Optolong Filters Clear Focusing 1.25\u2033 is specially designed to make focusing during astrophotography easier and more precise. When using narrowband filters, the image often becomes too dark or out of focus to focus accurately. This clear filter allows 98.5% of visible light (420-680 nm) to pass through, giving you a clear and contrast-rich image during focusing.<\/p>\n\n\n\n<p class=\"wp-block-paragraph\">By using this filter, you can find the right focus at lightning speed and then switch to your narrowband filter for the actual exposure. This produces sharper astrophotos and saves valuable time under the stars.<\/p>\n\n\n\n<p class=\"wp-block-paragraph\">The Optolong Clear Focusing Filter also has a dual function. It can remain permanently in your optical train as a dust cap and protective filter, preventing dust or dirt from getting onto the sensor or optics during long exposures. For astromodified DSLRs, it also offers increased efficiency and sensitivity by allowing the full visible spectrum to pass through virtually unhindered.<\/p>\n\n\n\n<p class=\"wp-block-paragraph\"><strong>Observation goals<\/strong><br>Ideal for astrophotographers who work with narrowband filters and have difficulty focusing in dim light conditions. This filter is suitable for use with CCD, CMOS and DSLR cameras and can also serve as a protective filter during extended shooting sessions.<\/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: Clear focus and protection filter<\/li>\n\n\n\n<li>Diameter: 1.25\u2033 (31.75 mm)<\/li>\n\n\n\n<li>Transmission: 98.5% in 420-680 nm range<\/li>\n\n\n\n<li>Suitable for: Astrophotography, focusing and optical protection<\/li>\n\n\n\n<li>Additional feature: Prevents dust accumulation during long exposures<\/li>\n\n\n\n<li>Housing: CNC-machined aluminum filter cell<\/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=\"317\" data-end=\"738\">\u00a0<\/p>\n<p data-start=\"147\" data-end=\"315\">Optolong Filters Clear Focusing 1,25&#8243; wordt geleverd met een helder focusfilter voor nauwkeurige scherpstelling en bescherming van de optiek.<\/p>\n<\/div>\n<\/div>\n<\/div>\n<\/div>\n<\/div>\n<\/div>\n<\/div>\n<\/div>\n<\/article>\n","protected":false},"featured_media":29193,"comment_status":"open","ping_status":"closed","template":"","meta":{"_acf_changed":false},"product_brand":[1548],"product_cat":[588],"product_tag":[],"class_list":["post-29180","product","type-product","status-publish","has-post-thumbnail","product_brand-optolong","product_cat-filters","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":29180,"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, 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2\"","src":"https:\/\/i0.wp.com\/www.telescoop.nl\/wp-content\/uploads\/2025\/09\/Optolong-Filters-L-eXtreme-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-L-eXtreme-2-.jpg?resize=350%2C200&ssl=1 1x, https:\/\/i0.wp.com\/www.telescoop.nl\/wp-content\/uploads\/2025\/09\/Optolong-Filters-L-eXtreme-2-.jpg?resize=525%2C300&ssl=1 1.5x, https:\/\/i0.wp.com\/www.telescoop.nl\/wp-content\/uploads\/2025\/09\/Optolong-Filters-L-eXtreme-2-.jpg?resize=700%2C400&ssl=1 2x, https:\/\/i0.wp.com\/www.telescoop.nl\/wp-content\/uploads\/2025\/09\/Optolong-Filters-L-eXtreme-2-.jpg?resize=1050%2C600&ssl=1 3x, https:\/\/i0.wp.com\/www.telescoop.nl\/wp-content\/uploads\/2025\/09\/Optolong-Filters-L-eXtreme-2-.jpg?resize=1400%2C800&ssl=1 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contrast.","rel":"","context":"Similar post","block_context":{"text":"Similar post","link":""},"img":{"alt_text":"Optolong Filters H-alpha 3nm 2\"","src":"https:\/\/i0.wp.com\/www.telescoop.nl\/wp-content\/uploads\/2025\/09\/Optolong-Filters-H-alpha-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-H-alpha-3nm-2-.jpg?resize=350%2C200&ssl=1 1x, https:\/\/i0.wp.com\/www.telescoop.nl\/wp-content\/uploads\/2025\/09\/Optolong-Filters-H-alpha-3nm-2-.jpg?resize=525%2C300&ssl=1 1.5x, https:\/\/i0.wp.com\/www.telescoop.nl\/wp-content\/uploads\/2025\/09\/Optolong-Filters-H-alpha-3nm-2-.jpg?resize=700%2C400&ssl=1 2x, https:\/\/i0.wp.com\/www.telescoop.nl\/wp-content\/uploads\/2025\/09\/Optolong-Filters-H-alpha-3nm-2-.jpg?resize=1050%2C600&ssl=1 3x, https:\/\/i0.wp.com\/www.telescoop.nl\/wp-content\/uploads\/2025\/09\/Optolong-Filters-H-alpha-3nm-2-.jpg?resize=1400%2C800&ssl=1 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