{"id":33639,"date":"2025-11-14T10:05:16","date_gmt":"2025-11-14T09:05:16","guid":{"rendered":"https:\/\/www.telescoop.nl\/?post_type=product&#038;p=33639"},"modified":"2026-09-10T14:45:34","modified_gmt":"2026-09-10T12:45:34","slug":"william-optics-ap-108-518-apochromatic-refractor-ultracat-wifd","status":"publish","type":"product","link":"https:\/\/www.telescoop.nl\/en\/william-optics-ap-108-518-apochromatische-refractor-ultracat-wifd\/","title":{"rendered":"William Optics AP 108\/518 Apochromatic Refractor UltraCat WIFD OTA"},"content":{"rendered":"<h2 class=\"wp-block-heading has-text-align-center\"><strong>The flagship: 108mm Petzval for full frame<\/strong><\/h2>\n\n\n\n<p class=\"wp-block-paragraph\">The <strong>William Optics UltraCat 108 WIFD<\/strong> is made for those who take their astrophotography to the highest level. The 108 mm Petzval optics provide a bright image across the entire frame, with no edge distortion and no separate flattener. Faster, simpler, and consistently beautiful shots.<\/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=\"33640\" src=\"https:\/\/www.telescoop.nl\/wp-content\/uploads\/2025\/11\/William-Optics-Apochromatische-refractor-AP-108-518-UltraCat-WIFD-10.jpg\" alt=\"William Optics UltraCat 108 WIFD apochromatic astrograph, full-frame\" class=\"wp-image-33640\" title=\"\"><\/figure>\n<\/figure>\n\n\n\n<div class=\"wp-block-columns is-layout-flex wp-container-core-columns-is-layout-8d39b2df wp-block-columns-is-layout-flex\">\n<div class=\"wp-block-column is-layout-flow wp-block-column-is-layout-flow\">\n<figure class=\"wp-block-image size-full\"><img decoding=\"async\" src=\"https:\/\/www.telescoop.nl\/wp-content\/uploads\/2025\/11\/William-Optics-Apochromatische-refractor-AP-108-518-UltraCat-WIFD-6.jpg\" alt=\"The UltraCat 108 with rotator and tilt flange\" class=\"wp-image-33644\" title=\"\"><\/figure>\n<\/div>\n\n\n\n<div class=\"wp-block-column is-layout-flow wp-block-column-is-layout-flow\">\n<h4 class=\"wp-block-heading\">Big light, full control<\/h4>\n\n\n\n<p class=\"wp-block-paragraph\">With a 518mm focal length at f\/4.8, the UltraCat 108 combines serious imaging scale with short exposures: from medium-sized nebulae to galaxy clusters. The included rotator and tilt lens provide full control over composition and sensor alignment, and the internal WIFD focuser carries heavy camera setups without shifting. The Bahtinov mask is integrated.<\/p>\n<\/div>\n<\/div>\n\n\n\n<h3 class=\"wp-block-heading\"><strong>In the box<\/strong><\/h3>\n\n\n\n<ul class=\"wp-block-list\">\n<li>UltraCat 108\/518 Optical Tube with WIFD Focuser and Petzval Corrector<\/li>\n\n\n\n<li>Rotator<\/li>\n\n\n\n<li>Candelabra<\/li>\n\n\n\n<li>Bahtinov mask<\/li>\n\n\n\n<li>Vixen-Style dovetail<\/li>\n<\/ul>\n\n\n\n<h3 class=\"wp-block-heading\"><strong>Featured accessories<\/strong><\/h3>\n\n\n\n<p class=\"wp-block-paragraph\">A <a href=\"https:\/\/www.telescoop.nl\/en\/telescope-accessories\/astro-photography\/other-astrophotography-accessories\/\">William Optics UniGuide 50mm Guidescope<\/a> (from 189 euros) is the fitting guide for this class. The M48 and M54 connectors directly accept common William Optics camera adapters.<\/p>\n\n\n\n<h4 class=\"wp-block-heading\">For whom yes, for whom no<\/h4>\n\n\n\n<p class=\"wp-block-paragraph\">For: advanced astrophotographers looking for a full-frame flagship with all the bells and whistles, on a sturdy equatorial mount. Not: for those who shoot mobile or on a star tracker; the Cat 51- and 71-class are built for that.<\/p>\n\n\n\n<h3 class=\"wp-block-heading\"><strong>Specifications<\/strong><\/h3>\n\n\n\n<figure class=\"wp-block-table\"><table><tbody><tr><td>Optical design<\/td><td>Apochromat, Petzval with integrated corrector<\/td><\/tr><tr><td>Opening<\/td><td>108 mm<\/td><\/tr><tr><td>Focal length<\/td><td>518 mm<\/td><\/tr><tr><td>Opening ratio<\/td><td>f\/4,8<\/td><\/tr><tr><td>Focuser<\/td><td>WIFD (intern)<\/td><\/tr><tr><td>Rotator and tilt flange<\/td><td>Included<\/td><\/tr><tr><td>Field of view<\/td><td>Flat to full-frame<\/td><\/tr><tr><td>Attachment<\/td><td>Vixen-Style dovetail<\/td><\/tr><tr><td>Execution<\/td><td>OTA (loose tube)<\/td><\/tr><\/tbody><\/table><\/figure>\n\n\n\n<p class=\"wp-block-paragraph\">Unsure about the right tube for your camera and mount? The <a href=\"https:\/\/www.telescoop.nl\/en\/telescope-selection-aid\/\">telescope selection aid<\/a> helps you choose. Also view all <a href=\"https:\/\/www.telescoop.nl\/en\/telescopes\/refracting-telescopes\/\">Refracting telescopes<\/a> and the full range of <a href=\"https:\/\/www.telescoop.nl\/en\/brands\/william-optics\/\">William Optics<\/a>.<\/p>","protected":false},"excerpt":{"rendered":"<p>William Optics UltraCat 108 WIFD: full-frame flagship 108\/518 f\/4.8 with integrated Petzval corrector, rotator, tilt adapter, and internal focuser. Supplied with Bahtinov mask and Vixen dovetail.<\/p>","protected":false},"featured_media":97184,"comment_status":"open","ping_status":"closed","template":"","meta":{"_acf_changed":false},"product_brand":[643],"product_cat":[51,428,3175,567],"product_tag":[],"class_list":["post-33639","product","type-product","status-publish","has-post-thumbnail","product_brand-william-optics","product_cat-telescopen","product_cat-telescopen-voor-astrofotografie","product_cat-refractor-ota","product_cat-refractor-telescopen","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":[34033,33941,33946,34072],"acf":[],"jetpack_sharing_enabled":true,"jetpack-related-posts":[{"id":111636,"url":"https:\/\/www.telescoop.nl\/en\/zwo-seestar-s50-pro\/","url_meta":{"origin":33639,"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\/33639","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=33639"}],"wp:featuredmedia":[{"embeddable":true,"href":"https:\/\/www.telescoop.nl\/en\/wp-json\/wp\/v2\/media\/97184"}],"wp:attachment":[{"href":"https:\/\/www.telescoop.nl\/en\/wp-json\/wp\/v2\/media?parent=33639"}],"wp:term":[{"taxonomy":"product_brand","embeddable":true,"href":"https:\/\/www.telescoop.nl\/en\/wp-json\/wp\/v2\/product_brand?post=33639"},{"taxonomy":"product_cat","embeddable":true,"href":"https:\/\/www.telescoop.nl\/en\/wp-json\/wp\/v2\/product_cat?post=33639"},{"taxonomy":"product_tag","embeddable":true,"href":"https:\/\/www.telescoop.nl\/en\/wp-json\/wp\/v2\/product_tag?post=33639"}],"curies":[{"name":"wp","href":"https:\/\/api.w.org\/{rel}","templated":true}]}}