{"id":33836,"date":"2025-11-15T12:38:38","date_gmt":"2025-11-15T11:38:38","guid":{"rendered":"https:\/\/www.telescoop.nl\/?post_type=product&p=33836"},"modified":"2026-05-18T16:10:41","modified_gmt":"2026-05-18T14:10:41","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":"

William Optics AP 81\/478 81 - Compact power with clear, tight image<\/strong><\/h3>\n\n\n\n

The William Optics AP 81\/478 81<\/strong> gives you sharp, calm images without color flaws. The apochromatic triplet design ensures pure colors, so your pictures look clean and professional. You get a bright, high-contrast viewing experience even if you don't have much experience with this type of telescope.<\/p>\n\n\n\n

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\"William<\/figure>\n<\/figure>\n\n\n\n

Clear images with natural colors<\/strong><\/h3>\n\n\n\n

The 81 mm aperture captures enough light to make visible details you miss with smaller telescopes. Think fine structures in star clusters or soft nebulae that would otherwise be lost. The image stays nice and sharp across the entire field, keeping your photos evenly exposed and clear. So you see exactly what you want to see - without the hassle.<\/p>\n\n\n\n

Perfect for photos and watching<\/strong><\/h3>\n\n\n\n

Are you using it visually? Then you will see Moon and planets with high contrast. Stars remain small dots, so globular clusters stand out nicely from the background.Want to photograph? Then you can work with a flattener\/reducer such as the Flat6AIII<\/strong>. This gives you a flat image all the way to the edges - ideal for full-frame cameras. The built-in dovetail in the handle makes it easy to place a guidescope.<\/p>\n\n\n\n

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\"\"<\/figure>\n<\/figure>\n\n\n\n

Smooth, precise focusing<\/strong><\/h3>\n\n\n\n

The 2.5\u2033 focuser moves softly and precisely. You have a long focus path, making it easy to find focus, even with different cameras or accessories. The fine 1:10 adjustment helps you put your focus exactly where you want it. Everything stays firmly in place, so your framing won't shift.<\/p>\n\n\n\n

Reliable and made for the road<\/strong><\/h3>\n\n\n\n

The tube is compact, light and sturdy. You can easily take it with you to dark locations and set it up quickly. The construction feels solid, keeping your image stable - even at higher magnification.The Bahtinov mask, which comes standard, helps you focus quickly and precisely. The lines are extra clear, making it easy to achieve focus even on fainter stars.<\/p>\n\n\n\n

For those who want to grow in astrophotography<\/strong><\/h3>\n\n\n\n

This telescope is ideal if you already have some experience and are looking for better results. You get an instrument that performs at a high level, yet remains easy to use. It is a good traveling companion as well as a strong tool for long nights under dark skies.<\/p>\n\n\n\n

Specifications<\/strong><\/h3>\n\n\n\n

Optics<\/strong><\/h4>\n\n\n\n
Feature<\/th>Description<\/th><\/tr><\/thead>
Type<\/td>Refractor<\/td><\/tr>
Design<\/td>Apochromat<\/td><\/tr>
Aperture (mm)<\/td>81<\/td><\/tr>
Focal length (mm)<\/td>478<\/td><\/tr>
Aperture ratio (f\/)<\/td>5,9<\/td><\/tr>
Resolution<\/td>1,70\u2033<\/td><\/tr>
Limit value (mag)<\/td>11,3<\/td><\/tr>
Light output<\/td>130<\/td><\/tr>
Max. useful magnification<\/td>162\u00d7<\/td><\/tr>
Tube weight (kg)<\/td>3,9<\/td><\/tr>
Transport length (mm)<\/td>390<\/td><\/tr>
Tube length (mm)<\/td>460<\/td><\/tr>
Coating<\/td>SMC multilayer coating<\/td><\/tr>
Stray light baffles<\/td>Yes<\/td><\/tr>
Lens Design<\/td>Triplet<\/td><\/tr><\/tbody><\/table><\/figure>\n\n\n\n

Focuser<\/strong><\/h4>\n\n\n\n
Feature<\/th>Description<\/th><\/tr><\/thead>
Design<\/td>Rack<\/td><\/tr>
Ocular connection<\/td>2\u2033<\/td><\/tr>
Free opening (mm)<\/td>64<\/td><\/tr>
Motorized<\/td>No<\/td><\/tr>
Ring clamp<\/td>Yes<\/td><\/tr>
Reduction<\/td>1:10 finesse<\/td><\/tr>
Connection (telescope side)<\/td>M63<\/td><\/tr><\/tbody><\/table><\/figure>\n\n\n\n

Mount<\/strong><\/h4>\n\n\n\n
Feature<\/th>Description<\/th><\/tr><\/thead>
Design<\/td>OTA<\/td><\/tr>
Type of mount<\/td>Without mount<\/td><\/tr><\/tbody><\/table><\/figure>\n\n\n\n

Included accessories<\/strong><\/h4>\n\n\n\n
Section<\/th>Description<\/th><\/tr><\/thead>
Seeker<\/td>No<\/td><\/tr>
Dew cap<\/td>Yes<\/td><\/tr>
Eyepiece adapter<\/td>2\u2033 \/ 1,25\u2033<\/td><\/tr>
Dovetail<\/td>Vixen-Style<\/td><\/tr>
Miscellaneous<\/td>Bahtinov Mask<\/td><\/tr>
Handle<\/td>Yes<\/td><\/tr>
Transport bag<\/td>Yes<\/td><\/tr><\/tbody><\/table><\/figure>\n\n\n\n

General<\/strong><\/h4>\n\n\n\n
Feature<\/th>Description<\/th><\/tr><\/thead>
Series<\/td>Gran Turismo<\/td><\/tr>
Color<\/td>Red<\/td><\/tr>
Observation goals<\/td>Astrophotography (very good), Moon & Planets, Nebulae & galaxies<\/td><\/tr>
Sun<\/td>No (only with appropriate filters)<\/td><\/tr>
Recommended for<\/td>Advanced<\/td><\/tr>
Observatory use<\/td>No<\/td><\/tr><\/tbody><\/table><\/figure>","protected":false},"excerpt":{"rendered":"

William Optics AP 81\/478 81 comes with a Vixen-Style dovetail, handle, Bahtinov mask, 2\u2033 to 1.25\u2033 adapter and a soft carrying case, ideal for mobile astrophotography. \u00a0<\/p>","protected":false},"featured_media":97332,"comment_status":"open","ping_status":"closed","template":"","meta":{"_acf_changed":false},"product_brand":[643],"product_cat":[51,3175,567],"product_tag":[],"class_list":["post-33836","product","type-product","status-publish","has-post-thumbnail","product_brand-william-optics","product_cat-telescopen","product_cat-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":[],"acf":[],"jetpack_sharing_enabled":true,"jetpack-related-posts":[{"id":33849,"url":"https:\/\/www.telescoop.nl\/en\/william-optics-granturismo-81-478-apo-wifd-ota\/","url_meta":{"origin":33836,"position":0},"title":"William Optics GranTurismo 81\/478 APO WIFD OTA","author":"","date":"15-11-2025","format":false,"excerpt":"William Optics AP 81\/478 81 comes with an internal WIFD focuser, Vixen-Style dovetail, handle, built-in field rotator, Bahtinov mask and a soft carrying case. \u00a0","rel":"","context":"Similar post","block_context":{"text":"Similar post","link":""},"img":{"alt_text":"","src":"","width":0,"height":0},"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 AP 81\/478 81 comes with a Vixen-Style dovetail, handle, Bahtinov mask, 2\" to 1.25\" adapter and a soft carrying case, ideal for mobile astrophotography. \u00a0","rel":"","context":"Similar post","block_context":{"text":"Similar post","link":""},"img":{"alt_text":"","src":"","width":0,"height":0},"classes":[]},{"id":33843,"url":"https:\/\/www.telescoop.nl\/en\/william-optics-granturismo-81-478-apo-iv-ota-grey\/","url_meta":{"origin":33836,"position":2},"title":"William Optics GranTurismo 81\/478 APO IV OTA","author":"","date":"15-11-2025","format":false,"excerpt":"William Optics AP 81\/478 81 comes with a Vixen-Style dovetail, handle, Bahtinov mask, 2\" to 1.25\" adapter and a soft carrying case, ideal for mobile astrophotography. \u00a0","rel":"","context":"Similar post","block_context":{"text":"Similar post","link":""},"img":{"alt_text":"","src":"","width":0,"height":0},"classes":[]},{"id":33886,"url":"https:\/\/www.telescoop.nl\/en\/william-optics-zenithstar-81-559-apo-wifd-goud-ota\/","url_meta":{"origin":33836,"position":3},"title":"William Optics ZenithStar 81\/559 APO WIFD Gold OTA","author":"","date":"15-11-2025","format":false,"excerpt":"William Optics AP 81\/559 81 wordt geleverd met een WIFD interne focuser, buisringen, Arca-Swiss & Vixen-style zwaluwstaart, handvat, Bahtinov-masker, adapters en een zachte draagtas. \u00a0","rel":"","context":"Similar post","block_context":{"text":"Similar post","link":""},"img":{"alt_text":"","src":"","width":0,"height":0},"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 AP 81\/559 81 wordt geleverd met een WIFD interne focuser, buisringen, Arca-Swiss & Vixen-style zwaluwstaart, handvat, Bahtinov-masker, adapters en een zachte draagtas. \u00a0","rel":"","context":"Similar post","block_context":{"text":"Similar post","link":""},"img":{"alt_text":"","src":"","width":0,"height":0},"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 comes with M63 telescope mount, M48 camera thread, integrated filter thread, 2-element optics, full-frame correction and distance ring for GT71 and GT81 - for sharp stars all the way to the image edge.","rel":"","context":"Similar post","block_context":{"text":"Similar post","link":""},"img":{"alt_text":"","src":"","width":0,"height":0},"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}]}}