{"id":33836,"date":"2025-11-15T12:38:38","date_gmt":"2025-11-15T11:38:38","guid":{"rendered":"https:\/\/www.telescoop.nl\/?post_type=product&#038;p=33836"},"modified":"2026-09-10T14:45:35","modified_gmt":"2026-09-10T12:45:35","slug":"william-optics-granturismo-81-478-apo-iv-ota-red","status":"publish","type":"product","link":"https:\/\/www.telescoop.nl\/en\/william-optics-granturismo-81-478-apo-iv-ota-rood\/","title":{"rendered":"William Optics GranTurismo 81\/478 APO IV OTA Red"},"content":{"rendered":"<h2 class=\"wp-block-heading has-text-align-center\"><strong>GranTurismo 81 IV in classic William Optics red<\/strong><\/h2>\n\n\n\n<p class=\"wp-block-paragraph\">The <strong>William Optics GranTurismo 81 IV Red<\/strong> It provides sharp, calm images without color errors. The apochromatic FPL-53 triplet ensures pure colors, so that shots look clean and professional, and the visual viewing experience is also clear and high-contrast, especially with the Moon, planets, and fine star fields.<\/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=\"33838\" src=\"https:\/\/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-1.jpg\" alt=\"William Optics GranTurismo 81 IV Red apochromatic triplet refractor, full frame\" class=\"wp-image-33838\" 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-OTAWilliam-Optics-AP-81478-81-Apochromatische-refractor-Gran-Turismo-IV-OTA-5.jpg\" alt=\"De GranTurismo 81 IV Red with Handle and Bahtinov Mask\" class=\"wp-image-33842\" 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\">Premium triplet, complete lever set<\/h4>\n\n\n\n<p class=\"wp-block-paragraph\">The 81mm triplet on a 478mm focal length (f\/5.9) provides image scale with travel weight. A handle, Vixen dovetail, Bahtinov mask, and the 2-to-1.25-inch adapter are included as standard, along with the soft carrying case. Set up, focus, and shoot.<\/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, red version<\/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\">For: Astrophotographers who want the GT81 triplet in the recognizable William Optics red. Not for: Those who choose by price; the standard version has the same optics and scope of delivery for 100 euros less.<\/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 (loose tube), Red<\/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 Red: FPL-53 triplet apochromatic 81\/478 f\/5.9 in red finish. Supplied with Vixen dovetail, handle, Bahtinov mask, adapter, and carrying case.<\/p>","protected":false},"featured_media":97332,"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-33836","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":33836,"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":33829,"url":"https:\/\/www.telescoop.nl\/en\/william-optics-granturismo-81-478-apo-iv-gold-ota\/","url_meta":{"origin":33836,"position":1},"title":"William Optics GranTurismo 81\/478 APO IV Gold OTA","author":"","date":"15-11-2025","format":false,"excerpt":"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.","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.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":33836,"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":33836,"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":33894,"url":"https:\/\/www.telescoop.nl\/en\/william-optics-zenithstar-81-559-apo-wifd-red-ota\/","url_meta":{"origin":33836,"position":4},"title":"William Optics ZenithStar 81\/559 APO WIFD Red OTA","author":"","date":"15-11-2025","format":false,"excerpt":"William Optics ZenithStar 81 WIFD Red: FPL-53 apochromat 81\/559 f\/6.9 with internal focuser, red finish. 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":34224,"url":"https:\/\/www.telescoop.nl\/en\/william-optics-flat-gt-flattener-gran-turismo-refractor-2-inch\/","url_meta":{"origin":33836,"position":5},"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":[]}],"_links":{"self":[{"href":"https:\/\/www.telescoop.nl\/en\/wp-json\/wp\/v2\/product\/33836","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=33836"}],"wp:featuredmedia":[{"embeddable":true,"href":"https:\/\/www.telescoop.nl\/en\/wp-json\/wp\/v2\/media\/97332"}],"wp:attachment":[{"href":"https:\/\/www.telescoop.nl\/en\/wp-json\/wp\/v2\/media?parent=33836"}],"wp:term":[{"taxonomy":"product_brand","embeddable":true,"href":"https:\/\/www.telescoop.nl\/en\/wp-json\/wp\/v2\/product_brand?post=33836"},{"taxonomy":"product_cat","embeddable":true,"href":"https:\/\/www.telescoop.nl\/en\/wp-json\/wp\/v2\/product_cat?post=33836"},{"taxonomy":"product_tag","embeddable":true,"href":"https:\/\/www.telescoop.nl\/en\/wp-json\/wp\/v2\/product_tag?post=33836"}],"curies":[{"name":"wp","href":"https:\/\/api.w.org\/{rel}","templated":true}]}}