{"id":33829,"date":"2025-11-15T12:17:44","date_gmt":"2025-11-15T11:17:44","guid":{"rendered":"https:\/\/www.telescoop.nl\/?post_type=product&#038;p=33829"},"modified":"2026-09-10T14:38:42","modified_gmt":"2026-09-10T12:38:42","slug":"william-optics-granturismo-81-478-apo-iv-gold-ota","status":"publish","type":"product","link":"https:\/\/www.telescoop.nl\/en\/william-optics-granturismo-81-478-apo-iv-gold-ota\/","title":{"rendered":"William Optics GranTurismo 81\/478 APO IV Gold OTA"},"content":{"rendered":"<h2 class=\"wp-block-heading has-text-align-center\"><strong>GranTurismo 81 IV in gold: a triplet for the traveling photographer<\/strong><\/h2>\n\n\n\n<p class=\"wp-block-paragraph\">The <strong>William Optics GranTurismo 81 IV Gold<\/strong> is the light, travel-friendly triplet that delivers truly premium-quality images. The FPL-53 triplet design keeps colors tightly together, ensuring photos remain calm, bright, and sharp, from star fields to the Moon.<\/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=\"33830\" src=\"https:\/\/www.telescoop.nl\/wp-content\/uploads\/2025\/11\/William-Optics-AP-81-478-81-Apochromatische-refractor-Gran-Turismo-IV-OTA-2.jpg\" alt=\"William Optics GranTurismo 81 IV Gold apochromatic triplet refractor, full-frame\" class=\"wp-image-33830\" 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-81-478-81-Apochromatische-refractor-Gran-Turismo-IV-OTA-1.jpg\" alt=\"De GranTurismo 81 IV Gold with handle and dovetail\" class=\"wp-image-33834\" 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\">Stable and immediately deployable<\/h4>\n\n\n\n<p class=\"wp-block-paragraph\">With an 81 mm aperture and 478 mm focal length (f\/5.9), the GT81 combines imaging scale with travel weight. The Bahtinov mask allows for precise focusing, the handle with Vixen dovetail mounts the tube to the mount in seconds, and the soft carrying case provides protection on the go. It's also a visual pleasure, via the 2-inch to 1.25-inch adapter.<\/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>Optical tube GranTurismo 81\/478 IV triplet, gold finish<\/li>\n\n\n\n<li>Vixen-Style dovetail<\/li>\n\n\n\n<li>Handle<\/li>\n\n\n\n<li>Bahtinov mask<\/li>\n\n\n\n<li>2 inch to 1.25 inch adapter<\/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 Flat GT flattener<\/a> (329 euro) flattens the field to full-frame; the UniGuide 32 mm guidescope (159 euro) 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\">Ideal for astrophotographers who want triplet quality in a golden finish, mobile and versatile. Not for those who want to rotate composition without detaching the photo train; the GT81 WIFD has a built-in rotator 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, FPL-53 triplet<\/td><\/tr><tr><td>Opening<\/td><td>81 millimeters<\/td><\/tr><tr><td>Focal length<\/td><td>478 mm<\/td><\/tr><tr><td>Opening ratio<\/td><td>f\/5,9<\/td><\/tr><tr><td>Focus assist<\/td><td>Bahtinov mask<\/td><\/tr><tr><td>Attachment<\/td><td>Vixen-style dovetail with handle<\/td><\/tr><tr><td>Execution<\/td><td>OTA (empty 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>William Optics GranTurismo 81 IV Gold: FPL-53 triplet apochromat 81\/478 f\/5.9 in gold finish. Delivered with Vixen dovetail, handle, Bahtinov mask, adapter, and carrying case.<\/p>","protected":false},"featured_media":97327,"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-33829","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":[34224,34101,34033,33941,33946,34082],"acf":[],"jetpack_sharing_enabled":true,"jetpack-related-posts":[{"id":33843,"url":"https:\/\/www.telescoop.nl\/en\/william-optics-granturismo-81-478-apo-iv-ota-grey\/","url_meta":{"origin":33829,"position":0},"title":"William Optics GranTurismo 81\/478 APO IV OTA","author":"","date":"15-11-2025","format":false,"excerpt":"William Optics GranTurismo 81 IV: FPL-53 triplet apochromaat 81\/478 f\/5,9, dezelfde optiek en leveromvang als de Gold- en Rood-uitvoeringen voor de scherpste prijs. Met zwaluwstaart, handvat, Bahtinov-masker en draagtas.","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":33836,"url":"https:\/\/www.telescoop.nl\/en\/william-optics-granturismo-81-478-apo-iv-ota-rood\/","url_meta":{"origin":33829,"position":1},"title":"William Optics GranTurismo 81\/478 APO IV OTA Red","author":"","date":"15-11-2025","format":false,"excerpt":"William Optics GranTurismo 81 IV Red: FPL-53 triplet apochromatic 81\/478 f\/5.9 in red finish. Supplied with Vixen dovetail, handle, Bahtinov mask, adapter, 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-81-478-81-Apochromatische-refractor-Gran-Turismo-IV-OTAWilliam-Optics-AP-81478-81-Apochromatische-refractor-Gran-Turismo-IV-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":33829,"position":2},"title":"William Optics GranTurismo 81\/478 APO WIFD OTA","author":"","date":"15-11-2025","format":false,"excerpt":"William Optics GranTurismo 81 WIFD: FPL-53 triplet apochromat 81\/478 f\/5.9 with internal WIFD focuser and built-in field rotator. Supplied with Vixen dovetail, handle, 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-81-478-81-Apochromatische-refractor-GranTurismo-WIFD-OTA-8.jpg?resize=350%2C200&ssl=1","width":350,"height":200},"classes":[]},{"id":33813,"url":"https:\/\/www.telescoop.nl\/en\/william-optics-granturismo-71-420-apo-ota\/","url_meta":{"origin":33829,"position":3},"title":"William Optics GranTurismo 71\/420 APO OTA","author":"","date":"14-11-2025","format":false,"excerpt":"William Optics GranTurismo 71: FPL-53 triplet apochromatic 71\/420 f\/5.9 with 2.5-inch rack-and-pinion focuser (1:10). Supplied with Bahtinov mask, adapters, Vixen dovetail, handle, and transport 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-71-420-GT-71-Apochromatische-refractor-Gran-Turismo-3.jpg?resize=350%2C200&ssl=1","width":350,"height":200},"classes":[]},{"id":34224,"url":"https:\/\/www.telescoop.nl\/en\/william-optics-flat-gt-flattener-gran-turismo-refractor-2-inch\/","url_meta":{"origin":33829,"position":4},"title":"William Optics Flat GT Flattener for GranTurismo Refractor","author":"","date":"17-11-2025","format":false,"excerpt":"William Optics Flat GT flattener for the GranTurismo 71 and 81: M63 telescope side, M48 camera side with filter thread, full-frame correction, and only 22 mm long.","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-Flat-GT-1.jpg?resize=350%2C200&ssl=1","width":350,"height":200},"classes":[]},{"id":33800,"url":"https:\/\/www.telescoop.nl\/en\/william-optics-fluorostar-120-780-apo-red-ota\/","url_meta":{"origin":33829,"position":5},"title":"William Optics Fluorostar 120\/780 APO Red OTA","author":"","date":"14-11-2025","format":false,"excerpt":"William Optics Fluorostar 120 Red: FPL-53 triplet apochromat 120\/780 f\/6.5 with lanthanum glass. Supplied with Losmandy dovetail, carrying handle, accessory shoe, Bahtinov mask, and transport 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-120-780-Apochromatische-refractor-AP-Fluorostar-Red-OTA-2.jpg?resize=350%2C200&ssl=1","width":350,"height":200},"classes":[]}],"_links":{"self":[{"href":"https:\/\/www.telescoop.nl\/en\/wp-json\/wp\/v2\/product\/33829","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=33829"}],"wp:featuredmedia":[{"embeddable":true,"href":"https:\/\/www.telescoop.nl\/en\/wp-json\/wp\/v2\/media\/97327"}],"wp:attachment":[{"href":"https:\/\/www.telescoop.nl\/en\/wp-json\/wp\/v2\/media?parent=33829"}],"wp:term":[{"taxonomy":"product_brand","embeddable":true,"href":"https:\/\/www.telescoop.nl\/en\/wp-json\/wp\/v2\/product_brand?post=33829"},{"taxonomy":"product_cat","embeddable":true,"href":"https:\/\/www.telescoop.nl\/en\/wp-json\/wp\/v2\/product_cat?post=33829"},{"taxonomy":"product_tag","embeddable":true,"href":"https:\/\/www.telescoop.nl\/en\/wp-json\/wp\/v2\/product_tag?post=33829"}],"curies":[{"name":"wp","href":"https:\/\/api.w.org\/{rel}","templated":true}]}}