{"id":33911,"date":"2025-11-15T14:24:36","date_gmt":"2025-11-15T13:24:36","guid":{"rendered":"https:\/\/www.telescoop.nl\/?post_type=product&p=33911"},"modified":"2026-03-04T16:58:01","modified_gmt":"2026-03-04T15:58:01","slug":"william-optics-pleiades-181-998-apo-septuplet-astrograph-ota","status":"publish","type":"product","link":"https:\/\/staging.telescoop.nl\/en\/william-optics-pleiades-181-998-apo-septuplet-astrograph-ota\/","title":{"rendered":"William Optics Pleiades 181\/998 APO Septuplet Astrograph OTA"},"content":{"rendered":"

William Optics 181 AP 181\/998 - Powerful deep sky astrograph<\/strong><\/h3>\n\n\n\n

The William Optics 181 AP 181\/998<\/strong> is a top-of-the-line apochromatic refractor built specifically for astrophotography. With the 7-element quadruplet lens and FPL-53 glass, you get bright, sharp images. Full-frame cameras are fully utilized, making stars, nebulae and galaxies look impressive.<\/p>\n\n\n\n

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

Fast and accurate photography<\/strong><\/h3>\n\n\n\n

With a fast f\/5.5 focal ratio, you can use shorter exposure times. That means less motion blur and faster results. Ideal for deep sky images, but also suitable for Moon and planets.<\/p>\n\n\n\n

Solid rack & pinion focuser<\/strong><\/h3>\n\n\n\n

The 3.7\u2033 R&P focuser lets you focus precisely. Movement is smooth and the ring clamp keeps your accessories stable. Fine adjustment 1:10 helps with precise focus, and everything is rotatable for maximum flexibility. Compatible with electronic focusing such as ZWO EAF.<\/p>\n\n\n\n

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

Compact and robust design<\/strong><\/h3>\n\n\n\n

Despite its 181 mm aperture, the Pleiades 181 is surprisingly portable. The handle makes transport easy. The telescope supports Losmandy prism beams and can carry William Optics viewfinders or tracking scopes. The included transport bag protects your telescope on the road.<\/p>\n\n\n\n

Complete for astrophotography<\/strong><\/h3>\n\n\n\n

The Pleiades 181 comes with Bahtinov focusing mask and adapters for CCD and DSLR cameras: M48, M54 and M68. It supports Canon, Nikon, Sony, Pentax, Fuji and Micro Four Thirds with optional T-adapters. Everything you need for serious astro shooting.<\/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>
Lens Design<\/td>Quadruplet<\/td><\/tr>
Aperture (mm)<\/td>181<\/td><\/tr>
Focal length (mm)<\/td>998<\/td><\/tr>
Aperture ratio (f\/)<\/td>5,5<\/td><\/tr>
Resolution<\/td>0,76\u2033<\/td><\/tr>
Limit value (mag)<\/td>12,3<\/td><\/tr>
Light output<\/td>670\u00d7<\/td><\/tr>
Max. useful magnification<\/td>362\u00d7<\/td><\/tr>
Corrected field of view (mm)<\/td>55<\/td><\/tr>
Tube length (mm)<\/td>1496<\/td><\/tr>
Transport length (mm)<\/td>1231<\/td><\/tr>
Tube weight (kg)<\/td>15<\/td><\/tr>
Coating<\/td>SMC multilayer coating<\/td><\/tr>
Stray light baffles<\/td>Yes<\/td><\/tr>
Glass material<\/td>OHARA FPL-53<\/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 & pinion (3.7\u2033)<\/td><\/tr>
Ocular connection<\/td>2\u2033<\/td><\/tr>
Ring clamp<\/td>Yes<\/td><\/tr>
Reduction<\/td>1:10 finesse<\/td><\/tr>
Rotatable<\/td>Yes<\/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>Without<\/td><\/tr>
Dew cap<\/td>Yes<\/td><\/tr>
Dovetail<\/td>Losmandy-Style<\/td><\/tr>
Miscellaneous<\/td>Bahtinov focus mask<\/td><\/tr>
Handle<\/td>Yes<\/td><\/tr>
Transport bag<\/td>Yes<\/td><\/tr>
Corrector<\/td>Integrated<\/td><\/tr>
Camera adapter<\/td>M54<\/td><\/tr><\/tbody><\/table><\/figure>\n\n\n\n

General<\/strong><\/h4>\n\n\n\n
Feature<\/th>Description<\/th><\/tr><\/thead>
Color<\/td>Belarus<\/td><\/tr>
Application<\/td>Astrophotography, Moon & Planets, Nebulae & galaxies<\/td><\/tr>
Recommended for<\/td>Advanced<\/td><\/tr>
Observatory use<\/td>Yes<\/td><\/tr><\/tbody><\/table><\/figure>","protected":false},"excerpt":{"rendered":"

William Optics 181 AP 181\/998 comes with an integrated 7-element corrector, 3.7\u2033 R&P focuser, Bahtinov mask, transport bag, Losmandy dovetail, handle and M48, M54 and M68 camera adapters. \u00a0 \u00a0 \u00a0 \u00a0 \u00a0 \u00a0 \u00a0 \u00a0 \u00a0 \u00a0 \u00a0 \u00a0 \u00a0 \u00a0 \u00a0 \u00a0 \u00a0 \u00a0 \u00a0 \u00a0 \u00a0 \u00a0 \u00a0 \u00a0 \u00a0 \u00a0 \u00a0 \u00a0 \u00a0 \u00a0 \u00a0 \u00a0 \u00a0 \u00a0 \u00a0 \u00a0 \u00a0 \u00a0 \u00a0 \u00a0 \u00a0 \u00a0 \u00a0 \u00a0 \u00a0 \u00a0 \u00a0 \u00a0 \u00a0 \u00a0 \u00a0 \u00a0 \u00a0 \u00a0 \u00a0 \u00a0 \u00a0 \u00a0 \u00a0 \u00a0 \u00a0 \u00a0 \u00a0 \u00a0<\/p>","protected":false},"featured_media":97397,"comment_status":"open","ping_status":"closed","template":"","meta":{"_acf_changed":false},"product_brand":[643],"product_cat":[51,567],"product_tag":[],"class_list":["post-33911","product","type-product","status-publish","has-post-thumbnail","product_brand-william-optics","product_cat-telescopen","product_cat-refractors","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":33917,"url":"https:\/\/staging.telescoop.nl\/en\/william-optics-pleiades-68-260-apo-astrograph-ota\/","url_meta":{"origin":33911,"position":0},"title":"William Optics Pleiades 68\/260 APO Astrograph OTA","author":"","date":"15-11-2025","format":false,"excerpt":"William Optics 68 AP 68\/260 comes with an integrated 7-element corrector, WIDF internal focuser, Bahtinov mask, transport bag, Vixen-style dovetail, handle and M48 and M54 camera adapters. \u00a0","rel":"","context":"Similar post","block_context":{"text":"Similar post","link":""},"img":{"alt_text":"","src":"https:\/\/i0.wp.com\/staging.telescoop.nl\/wp-content\/uploads\/2025\/11\/William-Optics-68-AP-68-260-Apochromatische-refractor-Pleiades-Astrograph-OTA-6.jpg?resize=350%2C200&ssl=1","width":350,"height":200,"srcset":"https:\/\/i0.wp.com\/staging.telescoop.nl\/wp-content\/uploads\/2025\/11\/William-Optics-68-AP-68-260-Apochromatische-refractor-Pleiades-Astrograph-OTA-6.jpg?resize=350%2C200&ssl=1 1x, https:\/\/i0.wp.com\/staging.telescoop.nl\/wp-content\/uploads\/2025\/11\/William-Optics-68-AP-68-260-Apochromatische-refractor-Pleiades-Astrograph-OTA-6.jpg?resize=525%2C300&ssl=1 1.5x, https:\/\/i0.wp.com\/staging.telescoop.nl\/wp-content\/uploads\/2025\/11\/William-Optics-68-AP-68-260-Apochromatische-refractor-Pleiades-Astrograph-OTA-6.jpg?resize=700%2C400&ssl=1 2x"},"classes":[]},{"id":33903,"url":"https:\/\/staging.telescoop.nl\/en\/william-optics-pleiades-111-528-apo-septuplet-astrograph-ota\/","url_meta":{"origin":33911,"position":1},"title":"William Optics Pleiades 111\/528 APO Septuplet Astrograph OTA","author":"","date":"15-11-2025","format":false,"excerpt":"William Optics 111 AP 111\/528 wordt geleverd met een ge\u00efntegreerde 7-lens corrector, WIDF interne focuser, Vixen-Style zwaluwstaart, handvat, Bahtinov-masker, M54 & M48 camera adapters en een zachte draagtas. \u00a0","rel":"","context":"Similar post","block_context":{"text":"Similar post","link":""},"img":{"alt_text":"","src":"https:\/\/i0.wp.com\/staging.telescoop.nl\/wp-content\/uploads\/2025\/11\/William-Optics-111-AP-111-528-Apochromatische-refractor-Pleiades-Astrograph-OTA-2.jpg?resize=350%2C200&ssl=1","width":350,"height":200,"srcset":"https:\/\/i0.wp.com\/staging.telescoop.nl\/wp-content\/uploads\/2025\/11\/William-Optics-111-AP-111-528-Apochromatische-refractor-Pleiades-Astrograph-OTA-2.jpg?resize=350%2C200&ssl=1 1x, https:\/\/i0.wp.com\/staging.telescoop.nl\/wp-content\/uploads\/2025\/11\/William-Optics-111-AP-111-528-Apochromatische-refractor-Pleiades-Astrograph-OTA-2.jpg?resize=525%2C300&ssl=1 1.5x, https:\/\/i0.wp.com\/staging.telescoop.nl\/wp-content\/uploads\/2025\/11\/William-Optics-111-AP-111-528-Apochromatische-refractor-Pleiades-Astrograph-OTA-2.jpg?resize=700%2C400&ssl=1 2x"},"classes":[]},{"id":33652,"url":"https:\/\/staging.telescoop.nl\/en\/william-optics-ap-51-178-apochromatische-refractor-minicat-wifd-ota\/","url_meta":{"origin":33911,"position":2},"title":"William Optics AP 51\/178 Apochromatic refractor MiniCat WIFD OTA","author":"","date":"14-11-2025","format":false,"excerpt":"William Optics AP 51\/178 wordt geleverd met een beschermende nylon draagtas, een ge\u00efntegreerd Bahtinov-masker, dauwkap en een Arca-Swiss & Vixen-Style zwaluwstaart. Deze ultracompacte astrograph is perfect voor op reis en voor astrofotografie met maximale beeldkwaliteit. \u00a0","rel":"","context":"Similar post","block_context":{"text":"Similar post","link":""},"img":{"alt_text":"","src":"https:\/\/i0.wp.com\/staging.telescoop.nl\/wp-content\/uploads\/2025\/11\/William-Optics-AP-51178-Apochromatische-refractor-MiniCat-WIFD-OTA-2.jpg?resize=350%2C200&ssl=1","width":350,"height":200,"srcset":"https:\/\/i0.wp.com\/staging.telescoop.nl\/wp-content\/uploads\/2025\/11\/William-Optics-AP-51178-Apochromatische-refractor-MiniCat-WIFD-OTA-2.jpg?resize=350%2C200&ssl=1 1x, https:\/\/i0.wp.com\/staging.telescoop.nl\/wp-content\/uploads\/2025\/11\/William-Optics-AP-51178-Apochromatische-refractor-MiniCat-WIFD-OTA-2.jpg?resize=525%2C300&ssl=1 1.5x, https:\/\/i0.wp.com\/staging.telescoop.nl\/wp-content\/uploads\/2025\/11\/William-Optics-AP-51178-Apochromatische-refractor-MiniCat-WIFD-OTA-2.jpg?resize=700%2C400&ssl=1 2x"},"classes":[]},{"id":33709,"url":"https:\/\/staging.telescoop.nl\/en\/william-optics-ultracat-76-365-apo-wifd-30th-anniversary-edition-ota\/","url_meta":{"origin":33911,"position":3},"title":"William Optics UltraCat 76\/365 APO WIFD 30th Anniversary Edition OTA","author":"","date":"14-11-2025","format":false,"excerpt":"William Optics AP 76\/365 76 30th comes with an integrated corrector, UniGuide 32 mm scope, Bahtinov mask, transport bag and commemorative certificate - the ideal, complete set for the discerning astrophotographer. \u00a0","rel":"","context":"Similar post","block_context":{"text":"Similar post","link":""},"img":{"alt_text":"","src":"https:\/\/i0.wp.com\/staging.telescoop.nl\/wp-content\/uploads\/2025\/11\/William-Optics-AP-76-365-76-30th-Apochromatische-refractor-UltraCat-WIFD-Anniversary-Edition-2.jpg?resize=350%2C200&ssl=1","width":350,"height":200,"srcset":"https:\/\/i0.wp.com\/staging.telescoop.nl\/wp-content\/uploads\/2025\/11\/William-Optics-AP-76-365-76-30th-Apochromatische-refractor-UltraCat-WIFD-Anniversary-Edition-2.jpg?resize=350%2C200&ssl=1 1x, https:\/\/i0.wp.com\/staging.telescoop.nl\/wp-content\/uploads\/2025\/11\/William-Optics-AP-76-365-76-30th-Apochromatische-refractor-UltraCat-WIFD-Anniversary-Edition-2.jpg?resize=525%2C300&ssl=1 1.5x, https:\/\/i0.wp.com\/staging.telescoop.nl\/wp-content\/uploads\/2025\/11\/William-Optics-AP-76-365-76-30th-Apochromatische-refractor-UltraCat-WIFD-Anniversary-Edition-2.jpg?resize=700%2C400&ssl=1 2x"},"classes":[]},{"id":33894,"url":"https:\/\/staging.telescoop.nl\/en\/william-optics-zenithstar-81-559-apo-wifd-red-ota\/","url_meta":{"origin":33911,"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":"https:\/\/i0.wp.com\/staging.telescoop.nl\/wp-content\/uploads\/2025\/11\/William-Optics-AP-81-559-81-Apochromatische-refractor-ZenithStar-WIFD-Red-OTA-2.jpg?resize=350%2C200&ssl=1","width":350,"height":200,"srcset":"https:\/\/i0.wp.com\/staging.telescoop.nl\/wp-content\/uploads\/2025\/11\/William-Optics-AP-81-559-81-Apochromatische-refractor-ZenithStar-WIFD-Red-OTA-2.jpg?resize=350%2C200&ssl=1 1x, https:\/\/i0.wp.com\/staging.telescoop.nl\/wp-content\/uploads\/2025\/11\/William-Optics-AP-81-559-81-Apochromatische-refractor-ZenithStar-WIFD-Red-OTA-2.jpg?resize=525%2C300&ssl=1 1.5x, https:\/\/i0.wp.com\/staging.telescoop.nl\/wp-content\/uploads\/2025\/11\/William-Optics-AP-81-559-81-Apochromatische-refractor-ZenithStar-WIFD-Red-OTA-2.jpg?resize=700%2C400&ssl=1 2x"},"classes":[]},{"id":33699,"url":"https:\/\/staging.telescoop.nl\/en\/william-optics-ap-71-350-71-apochromatische-refractor-redcat-wifd\/","url_meta":{"origin":33911,"position":5},"title":"William Optics AP 71\/350 71 Apochromatic refractor RedCat WIFD","author":"","date":"14-11-2025","format":false,"excerpt":"William Optics AP 71\/350 71 wordt geleverd met een beschermende nylon draagtas, een in de objectiefkap ingebouwd Bahtinov-masker voor perfecte scherpstelling, en een veelzijdige Arca-Swiss & Vixen-Style zwaluwstaart voor eenvoudige montage. \u00a0","rel":"","context":"Similar post","block_context":{"text":"Similar post","link":""},"img":{"alt_text":"","src":"https:\/\/i0.wp.com\/staging.telescoop.nl\/wp-content\/uploads\/2025\/11\/William-Optics-AP-71-350-71-Apochromatische-refractor-RedCat-WIFD-1.jpg?resize=350%2C200&ssl=1","width":350,"height":200,"srcset":"https:\/\/i0.wp.com\/staging.telescoop.nl\/wp-content\/uploads\/2025\/11\/William-Optics-AP-71-350-71-Apochromatische-refractor-RedCat-WIFD-1.jpg?resize=350%2C200&ssl=1 1x, https:\/\/i0.wp.com\/staging.telescoop.nl\/wp-content\/uploads\/2025\/11\/William-Optics-AP-71-350-71-Apochromatische-refractor-RedCat-WIFD-1.jpg?resize=525%2C300&ssl=1 1.5x, https:\/\/i0.wp.com\/staging.telescoop.nl\/wp-content\/uploads\/2025\/11\/William-Optics-AP-71-350-71-Apochromatische-refractor-RedCat-WIFD-1.jpg?resize=700%2C400&ssl=1 2x"},"classes":[]}],"_links":{"self":[{"href":"https:\/\/staging.telescoop.nl\/en\/wp-json\/wp\/v2\/product\/33911","targetHints":{"allow":["GET"]}}],"collection":[{"href":"https:\/\/staging.telescoop.nl\/en\/wp-json\/wp\/v2\/product"}],"about":[{"href":"https:\/\/staging.telescoop.nl\/en\/wp-json\/wp\/v2\/types\/product"}],"replies":[{"embeddable":true,"href":"https:\/\/staging.telescoop.nl\/en\/wp-json\/wp\/v2\/comments?post=33911"}],"wp:featuredmedia":[{"embeddable":true,"href":"https:\/\/staging.telescoop.nl\/en\/wp-json\/wp\/v2\/media\/97397"}],"wp:attachment":[{"href":"https:\/\/staging.telescoop.nl\/en\/wp-json\/wp\/v2\/media?parent=33911"}],"wp:term":[{"taxonomy":"product_brand","embeddable":true,"href":"https:\/\/staging.telescoop.nl\/en\/wp-json\/wp\/v2\/product_brand?post=33911"},{"taxonomy":"product_cat","embeddable":true,"href":"https:\/\/staging.telescoop.nl\/en\/wp-json\/wp\/v2\/product_cat?post=33911"},{"taxonomy":"product_tag","embeddable":true,"href":"https:\/\/staging.telescoop.nl\/en\/wp-json\/wp\/v2\/product_tag?post=33911"}],"curies":[{"name":"wp","href":"https:\/\/api.w.org\/{rel}","templated":true}]}}