{"id":34075,"date":"2025-11-16T15:38:41","date_gmt":"2025-11-16T14:38:41","guid":{"rendered":"https:\/\/www.telescoop.nl\/?post_type=product&#038;p=34075"},"modified":"2026-03-04T16:44:56","modified_gmt":"2026-03-04T15:44:56","slug":"william-optics-172-235mm-bahtinov-focus-mask","status":"publish","type":"product","link":"https:\/\/staging.telescoop.nl\/en\/william-optics-172-235mm-bahtinov-focusmasker\/","title":{"rendered":"William Optics 172-235mm Bahtinov Focus Mask"},"content":{"rendered":"<h3 class=\"wp-block-heading\"><strong>Focusing has never been easier<\/strong><\/h3>\n\n\n\n<p class=\"wp-block-paragraph\">The William Optics 172-235mm focus mask helps you focus quickly and precisely. It is made of high-quality acrylic glass with 92% light transmission. This keeps your image clear and sharp, even with faint stars.<\/p>\n\n\n\n<figure class=\"wp-block-gallery has-nested-images columns-default is-cropped wp-block-gallery-1 is-layout-flex wp-block-gallery-is-layout-flex\">\n<figure class=\"wp-block-image size-large\"><img decoding=\"async\" data-id=\"34076\" src=\"https:\/\/staging.telescoop.nl\/wp-content\/uploads\/2025\/11\/William-Optics-172-235mm-Focus-masker-Bahtinov-1.jpg\" alt=\"William Optics 172-235mm Focus mask Bahtinov of transparent acrylic glass with adjustable pins.\" class=\"wp-image-34076\" title=\"\"><\/figure>\n<\/figure>\n\n\n\n<h3 class=\"wp-block-heading\"><strong>Clearer bending pattern<\/strong><\/h3>\n\n\n\n<p class=\"wp-block-paragraph\">The imprint pattern of the mask is three times more pronounced than classic metal masks. You can see the curve better and find the perfect focus faster.<\/p>\n\n\n\n<h3 class=\"wp-block-heading\"><strong>Easy to use<\/strong><\/h3>\n\n\n\n<p class=\"wp-block-paragraph\">The mask fits telescopes from 172 to 235 mm in diameter. You simply place it over your telescope and you are instantly ready to focus. The acrylic glass provides a clear and high-contrast image.<\/p>\n\n\n\n<figure class=\"wp-block-gallery has-nested-images columns-default is-cropped wp-block-gallery-2 is-layout-flex wp-block-gallery-is-layout-flex\">\n<figure class=\"wp-block-image aligncenter size-large\"><img decoding=\"async\" data-id=\"34077\" src=\"https:\/\/staging.telescoop.nl\/wp-content\/uploads\/2025\/11\/William-Optics-172-235mm-Focus-masker-Bahtinov-2.jpg\" alt=\"William Optics 172-235mm Focus mask Bahtinov illustration comparing the brightness of the diffraction pattern.\" class=\"wp-image-34077\" title=\"\"><\/figure>\n<\/figure>\n\n\n\n<h3 class=\"wp-block-heading\"><strong>Specifications<\/strong><\/h3>\n\n\n\n<h4 class=\"wp-block-heading\"><strong>General<\/strong><\/h4>\n\n\n\n<figure class=\"wp-block-table\"><table class=\"has-fixed-layout\"><thead><tr><th>Feature<\/th><th>Description<\/th><\/tr><\/thead><tbody><tr><td>Color<\/td><td>Transparent<\/td><\/tr><tr><td>Material<\/td><td>Acrylic<\/td><\/tr><tr><td>Diameter (mm)<\/td><td>172-235<\/td><\/tr><tr><td>Type<\/td><td>Mask<\/td><\/tr><tr><td>Design<\/td><td>Focus Mask<\/td><\/tr><\/tbody><\/table><\/figure>","protected":false},"excerpt":{"rendered":"<p>William Optics 172-235mm Focus mask Bahtinov comes with adjustable mounting pins for telescopes from 172 to 235mm diameter. \u00a0<\/p>","protected":false},"featured_media":97503,"comment_status":"open","ping_status":"closed","template":"","meta":{"_acf_changed":false},"product_brand":[643],"product_cat":[3115,56],"product_tag":[],"class_list":["post-34075","product","type-product","status-publish","has-post-thumbnail","product_brand-william-optics","product_cat-focusing","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":34079,"url":"https:\/\/staging.telescoop.nl\/en\/william-optics-243-308mm-bahtinov-focusmasker\/","url_meta":{"origin":34075,"position":0},"title":"William Optics 243-308 mm Bahtinov Focus Mask","author":"","date":"16-11-2025","format":false,"excerpt":"William Optics 243-308mm comes as a high-quality focus mask made of optical acrylic glass with a light transmittance of 92%, providing an approx. three times brighter diffraction image than classic metal masks. \u00a0","rel":"","context":"Similar post","block_context":{"text":"Similar post","link":""},"img":{"alt_text":"","src":"https:\/\/i0.wp.com\/staging.telescoop.nl\/wp-content\/uploads\/2025\/11\/William-Optics-243-308mm-Focus-masker-Bahtinov-2.jpg?resize=350%2C200&ssl=1","width":350,"height":200,"srcset":"https:\/\/i0.wp.com\/staging.telescoop.nl\/wp-content\/uploads\/2025\/11\/William-Optics-243-308mm-Focus-masker-Bahtinov-2.jpg?resize=350%2C200&ssl=1 1x, https:\/\/i0.wp.com\/staging.telescoop.nl\/wp-content\/uploads\/2025\/11\/William-Optics-243-308mm-Focus-masker-Bahtinov-2.jpg?resize=525%2C300&ssl=1 1.5x, https:\/\/i0.wp.com\/staging.telescoop.nl\/wp-content\/uploads\/2025\/11\/William-Optics-243-308mm-Focus-masker-Bahtinov-2.jpg?resize=700%2C400&ssl=1 2x"},"classes":[]},{"id":34072,"url":"https:\/\/staging.telescoop.nl\/en\/william-optics-105-148mm-bahtinov-focusmasker\/","url_meta":{"origin":34075,"position":1},"title":"William Optics 105-148mm Bahtinov Focus Mask","author":"","date":"16-11-2025","format":false,"excerpt":"William Optics 105-148mm Focus mask Bahtinov comes with adjustable mounting pins for telescopes from 105 to 148mm diameter. \u00a0","rel":"","context":"Similar post","block_context":{"text":"Similar post","link":""},"img":{"alt_text":"","src":"https:\/\/i0.wp.com\/staging.telescoop.nl\/wp-content\/uploads\/2025\/11\/William-Optics-105-148mm-Focus-masker-Bahtinov-1.jpg?resize=350%2C200&ssl=1","width":350,"height":200,"srcset":"https:\/\/i0.wp.com\/staging.telescoop.nl\/wp-content\/uploads\/2025\/11\/William-Optics-105-148mm-Focus-masker-Bahtinov-1.jpg?resize=350%2C200&ssl=1 1x, https:\/\/i0.wp.com\/staging.telescoop.nl\/wp-content\/uploads\/2025\/11\/William-Optics-105-148mm-Focus-masker-Bahtinov-1.jpg?resize=525%2C300&ssl=1 1.5x, https:\/\/i0.wp.com\/staging.telescoop.nl\/wp-content\/uploads\/2025\/11\/William-Optics-105-148mm-Focus-masker-Bahtinov-1.jpg?resize=700%2C400&ssl=1 2x"},"classes":[]},{"id":34082,"url":"https:\/\/staging.telescoop.nl\/en\/william-optics-75-110mm-bahtinov-mask\/","url_meta":{"origin":34075,"position":2},"title":"William Optics 75-110mm Bahtinov Mask","author":"","date":"16-11-2025","format":false,"excerpt":"William Optics 75-110mm Focus mask Bahtinov comes as a high quality focus mask made of optical acrylic glass with 92% light transmission, providing an approx. three times brighter diffraction image than classic metal masks. \u00a0","rel":"","context":"Similar post","block_context":{"text":"Similar post","link":""},"img":{"alt_text":"","src":"https:\/\/i0.wp.com\/staging.telescoop.nl\/wp-content\/uploads\/2025\/11\/William-Optics-75-110mm-Focus-masker-Bahtinov-2.jpg?resize=350%2C200&ssl=1","width":350,"height":200,"srcset":"https:\/\/i0.wp.com\/staging.telescoop.nl\/wp-content\/uploads\/2025\/11\/William-Optics-75-110mm-Focus-masker-Bahtinov-2.jpg?resize=350%2C200&ssl=1 1x, https:\/\/i0.wp.com\/staging.telescoop.nl\/wp-content\/uploads\/2025\/11\/William-Optics-75-110mm-Focus-masker-Bahtinov-2.jpg?resize=525%2C300&ssl=1 1.5x, https:\/\/i0.wp.com\/staging.telescoop.nl\/wp-content\/uploads\/2025\/11\/William-Optics-75-110mm-Focus-masker-Bahtinov-2.jpg?resize=700%2C400&ssl=1 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\u00a0 \u00a0 \u00a0 \u00a0 \u00a0 \u00a0 \u00a0 \u00a0\u2026","rel":"","context":"Similar post","block_context":{"text":"Similar post","link":""},"img":{"alt_text":"","src":"https:\/\/i0.wp.com\/staging.telescoop.nl\/wp-content\/uploads\/2025\/11\/William-Optics-181-AP-181-998-Apochromatische-refractor-Pleiades-Astrograph-OTA-1.jpg?resize=350%2C200&ssl=1","width":350,"height":200,"srcset":"https:\/\/i0.wp.com\/staging.telescoop.nl\/wp-content\/uploads\/2025\/11\/William-Optics-181-AP-181-998-Apochromatische-refractor-Pleiades-Astrograph-OTA-1.jpg?resize=350%2C200&ssl=1 1x, https:\/\/i0.wp.com\/staging.telescoop.nl\/wp-content\/uploads\/2025\/11\/William-Optics-181-AP-181-998-Apochromatische-refractor-Pleiades-Astrograph-OTA-1.jpg?resize=525%2C300&ssl=1 1.5x, https:\/\/i0.wp.com\/staging.telescoop.nl\/wp-content\/uploads\/2025\/11\/William-Optics-181-AP-181-998-Apochromatische-refractor-Pleiades-Astrograph-OTA-1.jpg?resize=700%2C400&ssl=1 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