{"id":34085,"date":"2025-11-16T16:46:18","date_gmt":"2025-11-16T15:46:18","guid":{"rendered":"https:\/\/www.telescoop.nl\/?post_type=product&#038;p=34085"},"modified":"2026-08-25T15:11:40","modified_gmt":"2026-08-25T13:11:40","slug":"william-optics-flat61r-61-field-flattener-zenithstar","status":"publish","type":"product","link":"https:\/\/www.telescoop.nl\/en\/william-optics-flat61r-61-field-flattener-zenithstar\/","title":{"rendered":"William Optics Flat61R 61 Field Flattener for ZenithStar"},"content":{"rendered":"<h2 class=\"wp-block-heading has-text-align-center\"><strong>William Optics Flat61R 61 Field Flattener for ZenithStar: turns your 61 mm apo into an astrograph<\/strong><\/h2>\n\n\n\n<p class=\"wp-block-paragraph\">The William Optics Flat61R is the field flattener for the 61 mm apos from William Optics. Every refractor naturally produces a slightly curved focal plane; a flat camera sensor cuts through it, causing stars in the corners to stretch into streaks. A flattener corrects this curvature so that stars remain small and round all the way to the corners.<\/p>\n\n\n\n<p class=\"wp-block-paragraph\">The telescope side is an adjustable M54 connection: you screw the flattener onto the focuser and adjust the distance to the optics until the corner stars are sharp. The camera side is M48, with an integrated M48 filter thread so that your filter is directly in the optical train.<\/p>\n\n\n\n<figure class=\"wp-block-gallery has-nested-images columns-3 is-cropped wp-block-gallery-1 is-layout-flex wp-block-gallery-is-layout-flex\"><figure class=\"wp-block-image\"><img decoding=\"async\" src=\"https:\/\/www.telescoop.nl\/wp-content\/uploads\/2025\/11\/William-Optics-Flat61R-61-Beeldveldegalisator-voor-ZenithStar-1.jpg\" alt=\"William Optics Flat61R flattener for ZenithStar 61\" title=\"\"><\/figure><figure class=\"wp-block-image\"><img decoding=\"async\" src=\"https:\/\/www.telescoop.nl\/wp-content\/uploads\/2025\/11\/William-Optics-Flat61R-61-Beeldveldegalisator-voor-ZenithStar-2.jpg\" alt=\"William Optics Flat61R flattener for ZenithStar 61\" title=\"\"><\/figure><figure class=\"wp-block-image\"><img decoding=\"async\" src=\"https:\/\/www.telescoop.nl\/wp-content\/uploads\/2025\/11\/William-Optics-Flat61R-61-Beeldveldegalisator-voor-ZenithStar-4.jpg\" alt=\"William Optics Flat61R flattener for ZenithStar 61\" title=\"\"><\/figure><figure class=\"wp-block-image\"><img decoding=\"async\" src=\"https:\/\/www.telescoop.nl\/wp-content\/uploads\/2025\/11\/William-Optics-Flat61R-61-Beeldveldegalisator-voor-ZenithStar-3.jpg\" alt=\"William Optics Flat61R flattener for ZenithStar 61\" title=\"\"><\/figure><\/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\" style=\"flex-basis:38%\">\n<figure class=\"wp-block-image size-large\"><img decoding=\"async\" src=\"https:\/\/www.telescoop.nl\/wp-content\/uploads\/2025\/11\/William-Optics-Flat61R-61-Beeldveldegalisator-voor-ZenithStar-2.jpg\" alt=\"William Optics Flat61R flattener for ZenithStar 61\" title=\"\"><\/figure>\n<\/div>\n\n\n\n<div class=\"wp-block-column is-layout-flow wp-block-column-is-layout-flow\" style=\"flex-basis:62%\">\n<h4 class=\"wp-block-heading\">Which telescopes<\/h4>\n\n\n\n<p class=\"wp-block-paragraph\">Made for the William Optics ZenithStar 61 series and the GuideStar 61. In combination with the GuideStar 61, your guidescope transforms into a complete travel astrograph.<\/p>\n<\/div>\n<\/div>\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\" style=\"flex-basis:38%\">\n<figure class=\"wp-block-image size-large\"><img decoding=\"async\" src=\"https:\/\/www.telescoop.nl\/wp-content\/uploads\/2025\/11\/William-Optics-Flat61R-61-Beeldveldegalisator-voor-ZenithStar-4.jpg\" alt=\"William Optics Flat61R flattener for ZenithStar 61\" title=\"\"><\/figure>\n<\/div>\n\n\n\n<div class=\"wp-block-column is-layout-flow wp-block-column-is-layout-flow\" style=\"flex-basis:62%\">\n<h4 class=\"wp-block-heading\">Camera connection<\/h4>\n\n\n\n<p class=\"wp-block-paragraph\">On the M48 side, you connect your camera with a William Optics M48 adapter or 48 mm T-ring for your bayonet mount. This places the sensor at the distance for which the flattener is designed.<\/p>\n<\/div>\n<\/div>\n\n\n\n<h3 class=\"wp-block-heading\">Featured accessories<\/h3>\n\n\n\n<p class=\"wp-block-paragraph\">Combine the Flat61R with the M48 adapter for your cameramerk; these are listed as separate products in the product lineup.<\/p>\n\n\n\n<h3 class=\"wp-block-heading\">For whom yes and for whom no<\/h3>\n\n\n\n<ul class=\"wp-block-list\"><li>\u2713 Owners of a ZenithStar 61 or GuideStar 61 who want to take pictures<\/li><li>\u2713 Travel astrophotographers with small to APS-C sensors<\/li><li>\u2717 Owners of other tube diameters: every WO apo has its own calculated flattener<\/li><\/ul>\n\n\n\n<h3 class=\"wp-block-heading\">Specifications<\/h3>\n\n\n\n<figure class=\"wp-block-table\"><table class=\"has-fixed-layout\"><tbody><tr><td><strong>Type<\/strong><\/td><td>Field of view flattener<\/td><\/tr><tr><td><strong>Suitable for<\/strong><\/td><td>William Optics ZenithStar 61 \/ GuideStar 61<\/td><\/tr><tr><td><strong>Telescope silk<\/strong><\/td><td>M54, adjustable<\/td><\/tr><tr><td><strong>Camera side<\/strong><\/td><td>M48<\/td><\/tr><tr><td><strong>Filter thread<\/strong><\/td><td>M48, integrated<\/td><\/tr><\/tbody><\/table><\/figure>\n\n\n\n<p class=\"wp-block-paragraph\">You can find more accessories for this merk at the <a href=\"\/en\/brands\/william-optics\/\">William Optics merk Page<\/a>.<\/p>","protected":false},"excerpt":{"rendered":"<p>William Optics Flat61R flattener for the ZenithStar 61 and GuideStar 61: adjustable M54 connection, M48 camera side, and integrated M48 filter thread. Round stars all the way to the corners.<\/p>","protected":false},"featured_media":97510,"comment_status":"open","ping_status":"closed","template":"","meta":{"_acf_changed":false},"product_brand":[643],"product_cat":[469,3107,3105,3104,592],"product_tag":[],"class_list":["post-34085","product","type-product","status-publish","has-post-thumbnail","product_brand-william-optics","product_cat-astro-fotografie","product_cat-flatteners","product_cat-optische-accessoires","product_cat-overige-astrofotografie-accessoires","product_cat-reducers-flatteners","product_shipping_class-licht","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":34300,"url":"https:\/\/www.telescoop.nl\/en\/william-optics-flat73a-flattener-voor-zenithstar-73\/","url_meta":{"origin":34085,"position":0},"title":"William Optics Flat73A Flattener for ZenithStar 73","author":"","date":"17-11-2025","format":false,"excerpt":"William Optics Flat73A flattener for ZenithStar 73: M63 telescope side, M48 camera side, adjustable back focus with scale and direct M48 filter thread.","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-Flattener-Flat73A-voor-ZenithStar-73-5.jpg?resize=350%2C200&ssl=1","width":350,"height":200},"classes":[]},{"id":34298,"url":"https:\/\/www.telescoop.nl\/en\/william-optics-flat68iii-flattener\/","url_meta":{"origin":34085,"position":1},"title":"William Optics Flat68III Flattener","author":"","date":"17-11-2025","format":false,"excerpt":"William Optics Flat68III flattener: Ohara glass with full FMC coating, adjustable back focus with locking ring, M92 telescope side, T2 camera side, and integrated M48 filter thread.","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-Flat68III-Flattener-1.jpg?resize=350%2C200&ssl=1","width":350,"height":200},"classes":[]},{"id":33858,"url":"https:\/\/www.telescoop.nl\/en\/william-optics-zenithstar-61-360-apo-ii-ota-2\/","url_meta":{"origin":34085,"position":2},"title":"William Optics ZenithStar 61\/360 APO II OTA","author":"Info telescoop","date":"15-11-2025","format":false,"excerpt":"William Optics ZenithStar 61 II, scope OTA: compact FPL-53 apochromat 61\/360 f\/5.9 for astrophotography and visual use. Supplied with tube rings, Arca\/Vixen dovetail, and 2 to 1.25 inch adapter.","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-61-360-ZS61-II-Apochromatische-refractor-ZenithStar-OTA-1.jpg?resize=350%2C200&ssl=1","width":350,"height":200},"classes":[]},{"id":33869,"url":"https:\/\/www.telescoop.nl\/en\/william-optics-zenithstar-61-360-apo-ii-ota\/","url_meta":{"origin":34085,"position":3},"title":"William Optics ZenithStar 61\/360 APO II OTA with Flattener and Guidescope","author":"","date":"15-11-2025","format":false,"excerpt":"William Optics ZenithStar 61 II set: FPL-53 Apochromatic 61\/360 f\/5.9 complete with field flattener, UniGuide 32mm guidescope, tube rings, dovetail, and carrying case. Ready for guided astrophotography.","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-61-360-ZS61-II-Apochromatische-refractor-ZenithStar-OTA-3-1.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":34085,"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":34051,"url":"https:\/\/www.telescoop.nl\/en\/william-optics-61-guidescope-guide-star-apo-goud\/","url_meta":{"origin":34085,"position":5},"title":"William Optics 61 Guidescope Guide Star Apo Gold","author":"","date":"16-11-2025","format":false,"excerpt":"William Optics GuideStar 61 apo guidescope (gold) with FPL-53 lens: accurate guiding for refractors from 700 to 1200 mm. Includes Vixen rail 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-Guidescope-Guide-Star-Apo-61-4.jpg?resize=350%2C200&ssl=1","width":350,"height":200},"classes":[]}],"_links":{"self":[{"href":"https:\/\/www.telescoop.nl\/en\/wp-json\/wp\/v2\/product\/34085","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=34085"}],"wp:featuredmedia":[{"embeddable":true,"href":"https:\/\/www.telescoop.nl\/en\/wp-json\/wp\/v2\/media\/97510"}],"wp:attachment":[{"href":"https:\/\/www.telescoop.nl\/en\/wp-json\/wp\/v2\/media?parent=34085"}],"wp:term":[{"taxonomy":"product_brand","embeddable":true,"href":"https:\/\/www.telescoop.nl\/en\/wp-json\/wp\/v2\/product_brand?post=34085"},{"taxonomy":"product_cat","embeddable":true,"href":"https:\/\/www.telescoop.nl\/en\/wp-json\/wp\/v2\/product_cat?post=34085"},{"taxonomy":"product_tag","embeddable":true,"href":"https:\/\/www.telescoop.nl\/en\/wp-json\/wp\/v2\/product_tag?post=34085"}],"curies":[{"name":"wp","href":"https:\/\/api.w.org\/{rel}","templated":true}]}}