{"id":33849,"date":"2025-11-15T13:05:18","date_gmt":"2025-11-15T12:05:18","guid":{"rendered":"https:\/\/www.telescoop.nl\/?post_type=product&#038;p=33849"},"modified":"2026-09-10T14:38:42","modified_gmt":"2026-09-10T12:38:42","slug":"william-optics-granturismo-81-478-apo-wifd-ota","status":"publish","type":"product","link":"https:\/\/www.telescoop.nl\/en\/william-optics-granturismo-81-478-apo-wifd-ota\/","title":{"rendered":"William Optics GranTurismo 81\/478 APO WIFD OTA"},"content":{"rendered":"<h2 class=\"wp-block-heading has-text-align-center\"><strong>GT81 WIFD: triplet with internal focuser and built-in rotator<\/strong><\/h2>\n\n\n\n<p class=\"wp-block-paragraph\">The <strong>William Optics GranTurismo 81 WIFD<\/strong> is the most advanced GT81: the apochromatic triplet combined with the internal WIFD focuser and a built-in field rotator. Sharp stars, high color purity, and complete control over your composition, without disconnecting the imaging train.<\/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=\"33850\" src=\"https:\/\/www.telescoop.nl\/wp-content\/uploads\/2025\/11\/William-Optics-AP-81-478-81-Apochromatische-refractor-GranTurismo-WIFD-OTA-1.jpg\" alt=\"William Optics GranTurismo 81 WIFD apochromatic triplet refractor, full view\" class=\"wp-image-33850\" 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-GranTurismo-WIFD-OTA-6.jpg\" alt=\"The GranTurismo 81 WIFD with internal focuser and rotator\" class=\"wp-image-33855\" 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\">Remaining balance<\/h4>\n\n\n\n<p class=\"wp-block-paragraph\">The internal WIFD focuser does not shift any weight outside the tube: the balance on the mount remains constant, even with a heavy camera. The built-in rotator adjusts the composition precisely without affecting the focus. With a 478 mm brand focal length at f\/5.9, you can photograph nebulae and star fields quickly and consistently; the Bahtinov mask ensures precise focusing.<\/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 with WIFD focuser<\/li>\n\n\n\n<li>Built-in field rotator<\/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>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: demanding astrophotographers who want the GT81 triplet with internal focuser and rotator as a complete imaging tube. Not: those buying mainly on a budget; the standard GT81 IV delivers the same triplet optics with an external focuser for 400 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>Focuser<\/td><td>WIFD (intern)<\/td><\/tr><tr><td>Rotator<\/td><td>Built-in<\/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)<\/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 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.<\/p>","protected":false},"featured_media":97342,"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-33849","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":33849,"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. 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