{"id":33659,"date":"2025-11-14T12:14:14","date_gmt":"2025-11-14T11:14:14","guid":{"rendered":"https:\/\/www.telescoop.nl\/?post_type=product&#038;p=33659"},"modified":"2026-03-03T20:23:04","modified_gmt":"2026-03-03T19:23:04","slug":"william-optics-ap-51-250-apochromatic-refractor-redcat-wifd","status":"publish","type":"product","link":"https:\/\/staging.telescoop.nl\/en\/william-optics-ap-51-250-apochromatische-refractor-redcat-wifd\/","title":{"rendered":"William Optics AP 51\/250 Apochromatic refractor RedCat WIFD"},"content":{"rendered":"<h3 class=\"wp-block-heading\">Compact, powerful and instantly ready for crisp shots<\/h3>\n\n\n\n<p class=\"wp-block-paragraph\">The William Optics AP 51\/250 RedCat is built for photographers who want clear, flat images without the hassle.The fast f\/4.9 optic lets you make short exposures, so you get more good pictures in less time.Your image stays sharp all the way to the corners. Even if you're working with a full-frame camera.<\/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 aligncenter size-large\"><img decoding=\"async\" data-id=\"33660\" src=\"https:\/\/staging.telescoop.nl\/wp-content\/uploads\/2025\/11\/William-Optics-AP-51250-Apochromatische-refractor-RedCat-WIFD-1.jpg\" alt=\"William Optics AP 51\/250 Apochromatic refractor RedCat WIFD viewed obliquely from above with the lens cap next to it.\" class=\"wp-image-33660\" title=\"\"><\/figure>\n<\/figure>\n\n\n\n<h3 class=\"wp-block-heading\">Clear image thanks to Petzval design<\/h3>\n\n\n\n<p class=\"wp-block-paragraph\">The Petzval system with four-lens construction gives you a flat, color-clean image.You don't need a separate flattener, so your setup remains simple.The combination of FPL53 and FPL51 glass keeps stars round and tight, so you have less to correct in post-processing.<\/p>\n\n\n\n<h3 class=\"wp-block-heading\">Internal focusing for smooth operation<\/h3>\n\n\n\n<p class=\"wp-block-paragraph\">You focus via the internal WIFD focuser.Nothing slides out, nothing tilts, and even a heavy camera remains stable.The focus ring turns precisely and feels direct.Want automatic focus? The RedCat just works with the ZWO EAF motor.<\/p>\n\n\n\n<figure class=\"wp-block-gallery has-nested-images columns-default is-cropped wp-block-gallery-2 is-layout-flex wp-block-gallery-is-layout-flex\">\n<figure class=\"wp-block-image aligncenter size-large\"><img decoding=\"async\" data-id=\"33662\" src=\"https:\/\/staging.telescoop.nl\/wp-content\/uploads\/2025\/11\/William-Optics-AP-51250-Apochromatische-refractor-RedCat-WIFD-3.jpg\" alt=\"William Optics AP 51\/250 Apochromatic refractor RedCat WIFD full side view on white background.\" class=\"wp-image-33662\" title=\"\"><\/figure>\n<\/figure>\n\n\n\n<h3 class=\"wp-block-heading\">Ease of use for any setup<\/h3>\n\n\n\n<p class=\"wp-block-paragraph\">The M48 connector makes connecting your camera easy.The prism bar works with Arca-Swiss, Vixen and tripod screws.So you put the RedCat on almost any mount, photo tripod or portable tracker.<\/p>\n\n\n\n<h3 class=\"wp-block-heading\">For night and nature<\/h3>\n\n\n\n<p class=\"wp-block-paragraph\">This small telescope picks up large nebulae, star fields and deep-sky objects with ease.During the day, it delivers equally tight images of animals and landscapes.So you get one compact telescope that can handle everything.<\/p>\n\n\n\n<h3 class=\"wp-block-heading\">Smartly designed and ready to go<\/h3>\n\n\n\n<p class=\"wp-block-paragraph\">The aluminum tube feels solid.It is short, light and easy to transport.The Bahtinov mask is hidden in the dew cap, so you can always focus quickly and accurately.The included bag protects your telescope and keeps everything neatly together.<\/p>\n\n\n\n<h1 class=\"wp-block-heading\"><strong>Specifications<\/strong><\/h1>\n\n\n\n<h3 class=\"wp-block-heading\">Optics<\/h3>\n\n\n\n<figure class=\"wp-block-table\"><table class=\"has-fixed-layout\"><thead><tr><th>Feature<\/th><th>Description<\/th><\/tr><\/thead><tbody><tr><td>Type<\/td><td>Refractor<\/td><\/tr><tr><td>Design<\/td><td>Apochromat<\/td><\/tr><tr><td>Aperture (mm)<\/td><td>51<\/td><\/tr><tr><td>Focal length (mm)<\/td><td>250<\/td><\/tr><tr><td>Focal Ratio (f\/)<\/td><td>4,9<\/td><\/tr><tr><td>Resolution<\/td><td>2,71\u2033<\/td><\/tr><tr><td>Limit value (mag)<\/td><td>10,3<\/td><\/tr><tr><td>Light output<\/td><td>50<\/td><\/tr><tr><td>Max. useful magnification<\/td><td>102\u00d7<\/td><\/tr><tr><td>Tube weight (kg)<\/td><td>2,4<\/td><\/tr><tr><td>Tube length (mm)<\/td><td>346<\/td><\/tr><tr><td>Tube material<\/td><td>Aluminum<\/td><\/tr><tr><td>Coating<\/td><td>Multiple<\/td><\/tr><tr><td>Tube construction<\/td><td>Full tube<\/td><\/tr><tr><td>Dew cap diameter (mm)<\/td><td>80<\/td><\/tr><tr><td>Lens Design<\/td><td>Quadruplet<\/td><\/tr><\/tbody><\/table><\/figure>\n\n\n\n<h3 class=\"wp-block-heading\">Focuser<\/h3>\n\n\n\n<figure class=\"wp-block-table\"><table class=\"has-fixed-layout\"><thead><tr><th>Feature<\/th><th>Description<\/th><\/tr><\/thead><tbody><tr><td>Tilt adapter<\/td><td>Yes<\/td><\/tr><tr><td>Design<\/td><td>Internal<\/td><\/tr><tr><td>Camera connection<\/td><td>M48<\/td><\/tr><tr><td>Backfocus (mm)<\/td><td>59,7<\/td><\/tr><tr><td>Free opening (mm)<\/td><td>48<\/td><\/tr><tr><td>Adjustment range (mm)<\/td><td>0-23<\/td><\/tr><tr><td>Rotatable<\/td><td>Yes<\/td><\/tr><\/tbody><\/table><\/figure>\n\n\n\n<h3 class=\"wp-block-heading\">Mount<\/h3>\n\n\n\n<figure class=\"wp-block-table\"><table class=\"has-fixed-layout\"><thead><tr><th>Feature<\/th><th>Description<\/th><\/tr><\/thead><tbody><tr><td>Design<\/td><td>OTA<\/td><\/tr><tr><td>Type of mount<\/td><td>Without<\/td><\/tr><\/tbody><\/table><\/figure>\n\n\n\n<h3 class=\"wp-block-heading\">Included accessories<\/h3>\n\n\n\n<figure class=\"wp-block-table\"><table class=\"has-fixed-layout\"><thead><tr><th>Section<\/th><th>Description<\/th><\/tr><\/thead><tbody><tr><td>Dew cap<\/td><td>Yes<\/td><\/tr><tr><td>Transport bag<\/td><td>Yes<\/td><\/tr><tr><td>Focus Mask<\/td><td>Yes<\/td><\/tr><tr><td>Dovetail<\/td><td>Arca-Swiss &amp; Vixen-Style<\/td><\/tr><tr><td>Photo tripod connector<\/td><td>1\/4\u2033<\/td><\/tr><tr><td>Corrector<\/td><td>Integrated<\/td><\/tr><\/tbody><\/table><\/figure>\n\n\n\n<h3 class=\"wp-block-heading\">General<\/h3>\n\n\n\n<figure class=\"wp-block-table\"><table class=\"has-fixed-layout\"><thead><tr><th>Feature<\/th><th>Description<\/th><\/tr><\/thead><tbody><tr><td>Series<\/td><td>Cat<\/td><\/tr><tr><td>Color<\/td><td>Red<\/td><\/tr><tr><td>Application<\/td><td>Astrophotography, Moon &amp; Planets, Nebulae &amp; Galaxies, limited nature<\/td><\/tr><tr><td>Sun<\/td><td>Yes (only with appropriate sunscreens)<\/td><\/tr><tr><td>Recommended for<\/td><td>Advanced<\/td><\/tr><tr><td>Observatory use<\/td><td>No<\/td><\/tr><\/tbody><\/table><\/figure>","protected":false},"excerpt":{"rendered":"<p>William Optics AP 51\/250 comes with a protective nylon carrying case, integrated Bahtinov mask and a versatile Arca-Swiss &amp; Vixen-style prism beam - perfect for astrophotographers looking for a compact, color-clean and high-quality apochromatic refractor. \u00a0<\/p>","protected":false},"featured_media":97199,"comment_status":"open","ping_status":"closed","template":"","meta":{"_acf_changed":false},"product_brand":[643],"product_cat":[51,567],"product_tag":[],"class_list":["post-33659","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":33664,"url":"https:\/\/staging.telescoop.nl\/en\/william-optics-ap-51-250-apochromatische-refractor-spacecat-wifd-ota\/","url_meta":{"origin":33659,"position":0},"title":"William Optics AP 51\/250 Apochromatic refractor SpaceCat WIFD OTA","author":"","date":"14-11-2025","format":false,"excerpt":"William Optics AP 51\/250 comes with a protective nylon carrying case, an integrated Bahtinov mask for perfect focusing and a versatile Arca-Swiss\/Vixen-style dovetail rod, ideal for astrophotographers looking for a compact, high-quality telescope. \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-51250-Apochromatische-refractor-SpaceCat-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-51250-Apochromatische-refractor-SpaceCat-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-51250-Apochromatische-refractor-SpaceCat-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-51250-Apochromatische-refractor-SpaceCat-WIFD-OTA-2.jpg?resize=700%2C400&ssl=1 2x"},"classes":[]},{"id":34141,"url":"https:\/\/staging.telescoop.nl\/en\/william-optics-90-125-zenitprisma-redcat\/","url_meta":{"origin":33659,"position":1},"title":"William Optics 90\u00b0 1.25\u2033 Zenith prism RedCat","author":"","date":"17-11-2025","format":false,"excerpt":"William Optics 90\u00b0 comes with silver zenith prism, 1.25\" eyepiece connector, M56 telescope connector and ring clamp - perfect for RedCat 51 nature observation with upright viewing.","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-90%C2%B0-125-Zenitprisma-RedCat-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-90%C2%B0-125-Zenitprisma-RedCat-1.jpg?resize=350%2C200&ssl=1 1x, https:\/\/i0.wp.com\/staging.telescoop.nl\/wp-content\/uploads\/2025\/11\/William-Optics-90%C2%B0-125-Zenitprisma-RedCat-1.jpg?resize=525%2C300&ssl=1 1.5x, https:\/\/i0.wp.com\/staging.telescoop.nl\/wp-content\/uploads\/2025\/11\/William-Optics-90%C2%B0-125-Zenitprisma-RedCat-1.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":33659,"position":2},"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":[]},{"id":33652,"url":"https:\/\/staging.telescoop.nl\/en\/william-optics-ap-51-178-apochromatische-refractor-minicat-wifd-ota\/","url_meta":{"origin":33659,"position":3},"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":33676,"url":"https:\/\/staging.telescoop.nl\/en\/william-optics-ap-61-300-61-apochromatische-refractor-redcat-ota\/","url_meta":{"origin":33659,"position":4},"title":"William Optics AP 61\/300 61 Apochromatic refractor RedCat OTA","author":"","date":"14-11-2025","format":false,"excerpt":"William Optics AP 61\/300 61 comes with integrated corrector, field rotator, carrying case, Bahtinov mask, tube rings and Arca\/Vixen prism bar - compact quadruplet for razor-sharp astrophotos and nature shots. \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-61-300-61-Apochromatische-refractor-RedCat-OTA-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-61-300-61-Apochromatische-refractor-RedCat-OTA-1.jpg?resize=350%2C200&ssl=1 1x, https:\/\/i0.wp.com\/staging.telescoop.nl\/wp-content\/uploads\/2025\/11\/William-Optics-AP-61-300-61-Apochromatische-refractor-RedCat-OTA-1.jpg?resize=525%2C300&ssl=1 1.5x, https:\/\/i0.wp.com\/staging.telescoop.nl\/wp-content\/uploads\/2025\/11\/William-Optics-AP-61-300-61-Apochromatische-refractor-RedCat-OTA-1.jpg?resize=700%2C400&ssl=1 2x"},"classes":[]},{"id":33684,"url":"https:\/\/staging.telescoop.nl\/en\/william-optics-ap-71-350-71-apochromatische-refractor-redcat-ota\/","url_meta":{"origin":33659,"position":5},"title":"William Optics AP 71\/350 71 Apochromatic refractor RedCat OTA","author":"","date":"14-11-2025","format":false,"excerpt":"William Optics AP 71\/350 71 comes with a protective nylon carrying case, a Vixen\/Arca-Swiss dovetail and a Bahtinov mask integrated into the objective cap - ideal for astrophotographers who want perfect focus and portability. \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-OTA-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-OTA-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-OTA-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-OTA-1.jpg?resize=700%2C400&ssl=1 2x"},"classes":[]}],"_links":{"self":[{"href":"https:\/\/staging.telescoop.nl\/en\/wp-json\/wp\/v2\/product\/33659","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=33659"}],"wp:featuredmedia":[{"embeddable":true,"href":"https:\/\/staging.telescoop.nl\/en\/wp-json\/wp\/v2\/media\/97199"}],"wp:attachment":[{"href":"https:\/\/staging.telescoop.nl\/en\/wp-json\/wp\/v2\/media?parent=33659"}],"wp:term":[{"taxonomy":"product_brand","embeddable":true,"href":"https:\/\/staging.telescoop.nl\/en\/wp-json\/wp\/v2\/product_brand?post=33659"},{"taxonomy":"product_cat","embeddable":true,"href":"https:\/\/staging.telescoop.nl\/en\/wp-json\/wp\/v2\/product_cat?post=33659"},{"taxonomy":"product_tag","embeddable":true,"href":"https:\/\/staging.telescoop.nl\/en\/wp-json\/wp\/v2\/product_tag?post=33659"}],"curies":[{"name":"wp","href":"https:\/\/api.w.org\/{rel}","templated":true}]}}