{"id":33886,"date":"2025-11-15T13:50:07","date_gmt":"2025-11-15T12:50:07","guid":{"rendered":"https:\/\/www.telescoop.nl\/?post_type=product&#038;p=33886"},"modified":"2026-10-13T11:15:20","modified_gmt":"2026-10-13T09:15:20","slug":"william-optics-zenithstar-81-559-apo-wifd-gold-ota","status":"publish","type":"product","link":"https:\/\/www.telescoop.nl\/en\/william-optics-zenithstar-81-559-apo-wifd-goud-ota\/","title":{"rendered":"William Optics ZenithStar 81\/559 APO WIFD Gold OTA"},"content":{"rendered":"<h2 class=\"wp-block-heading has-text-align-center\"><strong>ZenithStar 81 with internal focuser: gold on the tracker<\/strong><\/h2>\n\n\n\n<p class=\"wp-block-paragraph\">The <strong>William Optics ZenithStar 81 WIFD Gold<\/strong> combines an 81mm FPL-53 doublet with the internal WIFD focuser. Light enough for a Star Adventurer or star tracker, powerful enough for serious deep-sky astrophotography: you'll be ready to shoot or observe in minutes.<\/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=\"33887\" src=\"https:\/\/www.telescoop.nl\/wp-content\/uploads\/2025\/11\/William-Optics-AP-81-559-81-Apochromatische-refractor-ZenithStar-WIFD-Goud-OTA-2.jpg\" alt=\"William Optics ZenithStar 81 WIFD Gold Apochromatic Refractor, Full Frame\" class=\"wp-image-33887\" 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-AP-81-559-81-Apochromatische-refractor-ZenithStar-WIFD-Goud-OTA-3.jpg\" alt=\"The ZenithStar 81 WIFD with internal focuser and handle\" class=\"wp-image-33888\" 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\">Sharp to the edge, stable under camera weight<\/h4>\n\n\n\n<p class=\"wp-block-paragraph\">The FPL-53 doublet keeps colors tight together, and the 559mm focal length (f\/6.9) provides a nice scale for nebulae and galaxies. The internal WIFD focuser doesn't move weight outside the tube: balance remains stable, and heavy camera setups don't sag. A Bahtinov mask and adapters are included.<\/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>ZenithStar 81\/559 Optical Tube with WIFD Focuser, Gold Edition<\/li>\n\n\n\n<li>Tube Rings<\/li>\n\n\n\n<li>Arca-Swiss and Vixen-Style dovetail<\/li>\n\n\n\n<li>Handle<\/li>\n\n\n\n<li>Bahtinov mask<\/li>\n\n\n\n<li>Adapters<\/li>\n\n\n\n<li>Soft carrier bag<\/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\">The <a href=\"https:\/\/www.telescoop.nl\/en\/telescope-accessories\/astro-photography\/other-astrophotography-accessories\/\">William Optics Flat6A III Adjustable Flattener-Reducer<\/a> (289 euros) flattens the field to full-frame; the UniGuide 32mm guidescope (159 euros) enables long exposures.<\/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: astrophotographers looking for a lightweight 81mm APO with an internal focuser, in gold finish with a sharp price advantage. Not for: those who want an integrated Petzval system without a separate flattener; look at the Cat series instead.<\/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, FPL-53 doublet<\/td><\/tr><tr><td>Opening<\/td><td>81 millimeters<\/td><\/tr><tr><td>Focal length<\/td><td>559 mm<\/td><\/tr><tr><td>Opening ratio<\/td><td>f\/6,9<\/td><\/tr><tr><td>Focuser<\/td><td>WIFD (intern)<\/td><\/tr><tr><td>Focus assist<\/td><td>Bahtinov mask<\/td><\/tr><tr><td>Attachment<\/td><td>Mounting rings with Arca-Swiss and Vixen-Style dovetail and handle<\/td><\/tr><tr><td>Execution<\/td><td>OTA (loose tube), Gold<\/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><strong>This is just the tube (OTA), without mounting and tripod.<\/strong> You can choose the appropriate mounting and the accessories that come with it below.<\/p>\n<p>William Optics ZenithStar 81 WIFD Gold: FPL-53 apochromatic 81\/559 f\/6.9 with internal focuser. Supplied with tube rings, Arca\/Vixen dovetail, handle, Bahtinov mask, adapters, and carrying case.<\/p>","protected":false},"featured_media":97375,"comment_status":"open","ping_status":"closed","template":"","meta":{"_acf_changed":false},"product_brand":[643],"product_cat":[51,428,3175,567],"product_tag":[3352,3353],"class_list":["post-33886","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","product_tag-sterrenkijker","product_tag-sterrenkijkers","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":[90626,27732,32949,15860,34228,34101,34033,33941,33946,34082],"acf":[],"jetpack_sharing_enabled":true,"jetpack-related-posts":[{"id":33894,"url":"https:\/\/www.telescoop.nl\/en\/william-optics-zenithstar-81-559-apo-wifd-red-ota\/","url_meta":{"origin":33886,"position":0},"title":"William Optics ZenithStar 81\/559 APO WIFD Red OTA","author":"","date":"15-11-2025","format":false,"excerpt":"This is just the tube (OTA), without mounting and tripod. A suitable mounting and the accessories that come with it can be selected below. William Optics ZenithStar 81 WIFD Red: FPL-53 achromatic 81\/559 f\/6.9 with internal focus, red version. Supplied with tube rings, Arca\/Vixen dovetail, handle, Bahtinov mask, adapters and carrying case.","rel":"","context":"Similar post","block_context":{"text":"Similar post","link":""},"img":{"alt_text":"","src":"https:\/\/i0.wp.com\/www.telescoop.nl\/wp-content\/uploads\/2025\/11\/William-Optics-AP-81-559-81-Apochromatische-refractor-ZenithStar-WIFD-Red-OTA-3.jpg?resize=350%2C200&ssl=1","width":350,"height":200},"classes":[]},{"id":33881,"url":"https:\/\/www.telescoop.nl\/en\/william-optics-zenithstar-73-430-apo-gold-ota\/","url_meta":{"origin":33886,"position":1},"title":"William Optics ZenithStar 73\/430 APO Gold OTA","author":"","date":"15-11-2025","format":false,"excerpt":"This is just the tube (OTA), without the mounting and tripod. You can choose the appropriate mounting and the accessories that come with it below. William Optics ZenithStar 73 Gold: FPL-53 achromatic 73\/430 f\/5.9 for mobile astrophotography. Supplied with tube rings, Vixen eagle-tailed mount, handle with prism clip, Bahtinov mask and carrying case.","rel":"","context":"Similar post","block_context":{"text":"Similar post","link":""},"img":{"alt_text":"","src":"https:\/\/i0.wp.com\/www.telescoop.nl\/wp-content\/uploads\/2025\/11\/William-Optics-AP-73-430-73-Apochromatische-refractor-Super-ZenithStar-Gold-OTA-2.jpg?resize=350%2C200&ssl=1","width":350,"height":200},"classes":[]},{"id":33849,"url":"https:\/\/www.telescoop.nl\/en\/william-optics-granturismo-81-478-apo-wifd-ota\/","url_meta":{"origin":33886,"position":2},"title":"William Optics GranTurismo 81\/478 APO WIFD OTA","author":"","date":"15-11-2025","format":false,"excerpt":"This is just the tube (OTA), without mounting and tripod. You can choose the appropriate mounting and the accessories that come with it below. William Optics GranTurismo 81 WIFD: FPL-53 triplet apochromatic 81\/478 f\/5.9 with internal WIFD focus and built-in field rotator. Supplied with Vixen falcon-tail, handle, Bahtinov mask and carrying bag.","rel":"","context":"Similar post","block_context":{"text":"Similar post","link":""},"img":{"alt_text":"","src":"https:\/\/i0.wp.com\/www.telescoop.nl\/wp-content\/uploads\/2025\/11\/William-Optics-AP-81-478-81-Apochromatische-refractor-GranTurismo-WIFD-OTA-8.jpg?resize=350%2C200&ssl=1","width":350,"height":200},"classes":[]},{"id":33843,"url":"https:\/\/www.telescoop.nl\/en\/william-optics-granturismo-81-478-apo-iv-ota-grey\/","url_meta":{"origin":33886,"position":3},"title":"William Optics GranTurismo 81\/478 APO IV OTA","author":"","date":"15-11-2025","format":false,"excerpt":"This is just the tube (OTA), without the mounting and tripod. You can choose the appropriate mounting and the accessories that come with it below. William Optics GranTurismo 81 IV: FPL-53 triplet apochromatic 81\/478 f\/5.9, the same optics and scope as the Gold and Red versions for the best price. With dovetail mount, handle, Bahtinov mask and\u2026","rel":"","context":"Similar post","block_context":{"text":"Similar post","link":""},"img":{"alt_text":"","src":"https:\/\/i0.wp.com\/www.telescoop.nl\/wp-content\/uploads\/2025\/11\/William-Optics-AP-81-478-81-Apochromatische-refractor-Gran-Turismo-IV-OTA-3-1.jpg?resize=350%2C200&ssl=1","width":350,"height":200},"classes":[]},{"id":33829,"url":"https:\/\/www.telescoop.nl\/en\/william-optics-granturismo-81-478-apo-iv-gold-ota\/","url_meta":{"origin":33886,"position":4},"title":"William Optics GranTurismo 81\/478 APO IV Gold OTA","author":"","date":"15-11-2025","format":false,"excerpt":"This is just the tube (OTA), without the mounting and tripod. 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Supplied with Bahtinov mask, prism bar and carrying case.","rel":"","context":"Similar post","block_context":{"text":"Similar post","link":""},"img":{"alt_text":"","src":"https:\/\/i0.wp.com\/www.telescoop.nl\/wp-content\/uploads\/2025\/11\/William-Optics-AP-51250-Apochromatische-refractor-RedCat-WIFD-4.jpg?resize=350%2C200&ssl=1","width":350,"height":200},"classes":[]}],"_links":{"self":[{"href":"https:\/\/www.telescoop.nl\/en\/wp-json\/wp\/v2\/product\/33886","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=33886"}],"wp:featuredmedia":[{"embeddable":true,"href":"https:\/\/www.telescoop.nl\/en\/wp-json\/wp\/v2\/media\/97375"}],"wp:attachment":[{"href":"https:\/\/www.telescoop.nl\/en\/wp-json\/wp\/v2\/media?parent=33886"}],"wp:term":[{"taxonomy":"product_brand","embeddable":true,"href":"https:\/\/www.telescoop.nl\/en\/wp-json\/wp\/v2\/product_brand?post=33886"},{"taxonomy":"product_cat","embeddable":true,"href":"https:\/\/www.telescoop.nl\/en\/wp-json\/wp\/v2\/product_cat?post=33886"},{"taxonomy":"product_tag","embeddable":true,"href":"https:\/\/www.telescoop.nl\/en\/wp-json\/wp\/v2\/product_tag?post=33886"}],"curies":[{"name":"wp","href":"https:\/\/api.w.org\/{rel}","templated":true}]}}