{"id":112899,"date":"2026-10-09T16:52:45","date_gmt":"2026-10-09T14:52:45","guid":{"rendered":"https:\/\/www.telescoop.nl\/?post_type=product&#038;p=112899"},"modified":"2026-10-09T20:32:01","modified_gmt":"2026-10-09T18:32:01","slug":"adjustment-screws-for-the-catch-mirror-of-the-at6rc-and-at8rc-ritchey-chretien-bobs-knobs","status":"publish","type":"product","link":"https:\/\/www.telescoop.nl\/en\/afstelschroeven-voor-de-vangspiegel-van-de-at6rc-en-at8rc-ritchey-chretien-bobs-knobs\/","title":{"rendered":"Adjusting screws for the windshield of the AT6RC and AT8RC Ritchey-Chr\u00e9tien | Bob\u2019s Knobs"},"content":{"rendered":"<p class=\"wp-block-paragraph\">If you see stars extending out at the edge of the image in your footage, then the collimation of your Ritchey-Chr\u00e9tien may not be quite right. Adjustments are made to the secondary mirror. With Bob\u2019s Knobs for the AT6RC and AT8RC, you turn knobs instead of screws that require tools.<\/p>\n\n\n\n<p class=\"wp-block-paragraph\">The AT6RC and AT8RC are Ritchey-Chr\u00e9tien telescopes of 6 and 8 inches, widely used for astrophotography. You will find more of this type at <a href=\"https:\/\/www.telescoop.nl\/en\/telescopes\/reflector-telescopes\/ritchey-chretien-telescopes\/\">Ritchey-Chr\u00e9tien telescopes<\/a>. Check beforehand whether you have exactly one of these two models.<\/p>\n\n\n\n<p class=\"wp-block-paragraph\">Always turn just a very small amount and replace the screws one by one so that the mirror stays in place. After collimation, focus sharply with a <a href=\"https:\/\/www.telescoop.nl\/en\/telescope-accessories\/astro-photography\/other-astrophotography-accessories\/focusing\/\">Bahtinov mask tailored to your tube<\/a>, Then you immediately see if the stars are tight again.<\/p>\n\n\n\n<p class=\"wp-block-paragraph\">There is a special version for the large 16 inch RC from GSO. <a href=\"https:\/\/www.telescoop.nl\/en\/adjustment-screws-for-the-gso-16-inch-ritchey-chretien-rc-bobs-knobs\/\">separate set for the 16 inch RC<\/a>.<\/p>","protected":false},"excerpt":{"rendered":"<p>Adjustment buttons from Bob\u2019s Knobs for the viewfinder of the AT6RC and AT8RC, so you can quickly adjust the collimation by hand.<\/p>","protected":false},"featured_media":112898,"comment_status":"open","ping_status":"closed","template":"","meta":{"_acf_changed":false},"product_brand":[1559],"product_cat":[56,3091],"product_tag":[],"class_list":["post-112899","product","type-product","status-publish","has-post-thumbnail","product_brand-bobs-knobs","product_cat-telescoop-accessoires","product_cat-telescoop-onderdelen","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":111636,"url":"https:\/\/www.telescoop.nl\/en\/zwo-seestar-s50-pro\/","url_meta":{"origin":112899,"position":0},"title":"ZWO Seestar S50 Pro","author":"Info telescoop","date":"25-08-2026","format":false,"excerpt":"The ZWO Seestar S50 Pro is the successor to the Seestar S50: 50 mm quadruplet APO (260 mm, f\/5.2), two 8.3 MP 4K sensors, a 63-degree wide-angle camera for the Milky Way up to 8K, three built-in filters, a 10,000 mAh battery (up to 9 hours), and 128 GB of storage. Four capture modes for...","rel":"","context":"With 5 comments","block_context":{"text":"With 5 comments","link":"https:\/\/www.telescoop.nl\/en\/zwo-seestar-s50-pro\/#comments"},"img":{"alt_text":"ZWO Seestar S50 Pro hero","src":"https:\/\/i0.wp.com\/www.telescoop.nl\/wp-content\/uploads\/2026\/08\/zwo-seestar-s50-pro.jpg?resize=350%2C200&ssl=1","width":350,"height":200,"srcset":"https:\/\/i0.wp.com\/www.telescoop.nl\/wp-content\/uploads\/2026\/08\/zwo-seestar-s50-pro.jpg?resize=350%2C200&ssl=1 1x, https:\/\/i0.wp.com\/www.telescoop.nl\/wp-content\/uploads\/2026\/08\/zwo-seestar-s50-pro.jpg?resize=525%2C300&ssl=1 1.5x, https:\/\/i0.wp.com\/www.telescoop.nl\/wp-content\/uploads\/2026\/08\/zwo-seestar-s50-pro.jpg?resize=700%2C400&ssl=1 2x"},"classes":[]}],"_links":{"self":[{"href":"https:\/\/www.telescoop.nl\/en\/wp-json\/wp\/v2\/product\/112899","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=112899"}],"wp:featuredmedia":[{"embeddable":true,"href":"https:\/\/www.telescoop.nl\/en\/wp-json\/wp\/v2\/media\/112898"}],"wp:attachment":[{"href":"https:\/\/www.telescoop.nl\/en\/wp-json\/wp\/v2\/media?parent=112899"}],"wp:term":[{"taxonomy":"product_brand","embeddable":true,"href":"https:\/\/www.telescoop.nl\/en\/wp-json\/wp\/v2\/product_brand?post=112899"},{"taxonomy":"product_cat","embeddable":true,"href":"https:\/\/www.telescoop.nl\/en\/wp-json\/wp\/v2\/product_cat?post=112899"},{"taxonomy":"product_tag","embeddable":true,"href":"https:\/\/www.telescoop.nl\/en\/wp-json\/wp\/v2\/product_tag?post=112899"}],"curies":[{"name":"wp","href":"https:\/\/api.w.org\/{rel}","templated":true}]}}