{"id":92489,"date":"2026-01-05T17:56:19","date_gmt":"2026-01-05T16:56:19","guid":{"rendered":"https:\/\/www.telescoop.nl\/?post_type=product&#038;p=92489"},"modified":"2026-10-13T11:15:01","modified_gmt":"2026-10-13T09:15:01","slug":"omegon-ogdo-eyepiece-4mm-80","status":"publish","type":"product","link":"https:\/\/www.telescoop.nl\/en\/omegon-ogdo-oculair-4mm-80\/","title":{"rendered":"Omegon OGDO 4mm Eyepiece 80\u00b0 (1.25\" and 2\")"},"content":{"rendered":"<h2 class=\"wp-block-heading has-text-align-center\"><strong>Omegon OGDO 4 mm eyepiece 80\u00b0 (1.25 and 2 inch): lanthanum ED optics with 80 degree field of view<\/strong><\/h2>\n\n\n\n<p class=\"wp-block-paragraph\">The Omegon OGDO 4 mm is the top-of-the-line model among Omegon eyepieces: lanthanum ED glass from the Japanese Ohara, a field of view of 80 degrees and stars that remain point-shaped to the edge.<\/p>\n\n\n\n<p class=\"wp-block-paragraph\">The all-metal housing is waterproof and dustproof, with a rotating eyepiece and 20mm eye relief. A flannel storage bag and two protective caps are included.<\/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\/2026\/01\/Omegon-Oculair-OGDO-4mm-80d-4.jpg\" alt=\"Omegon OGDO 4 mm eyepiece with 80 degree field of view\" title=\"\"><\/figure><figure class=\"wp-block-image\"><img decoding=\"async\" src=\"https:\/\/www.telescoop.nl\/wp-content\/uploads\/2026\/01\/Omegon-Oculair-OGDO-4mm-80d.jpg\" alt=\"Omegon OGDO 4 mm eyepiece with 80 degree field of view\" title=\"\"><\/figure><figure class=\"wp-block-image\"><img decoding=\"async\" src=\"https:\/\/www.telescoop.nl\/wp-content\/uploads\/2026\/01\/Omegon-Oculair-OGDO-4mm-80d-2.jpg\" alt=\"Omegon OGDO 4 mm eyepiece with 80 degree field of view\" title=\"\"><\/figure><figure class=\"wp-block-image\"><img decoding=\"async\" src=\"https:\/\/www.telescoop.nl\/wp-content\/uploads\/2026\/01\/Omegon-Oculair-OGDO-4mm-80d-1.jpg\" alt=\"Omegon OGDO 4 mm eyepiece with 80 degree field of view\" title=\"\"><\/figure><figure class=\"wp-block-image\"><img decoding=\"async\" src=\"https:\/\/www.telescoop.nl\/wp-content\/uploads\/2026\/01\/Omegon-Oculair-OGDO-4mm-80d-3.jpg\" alt=\"Omegon OGDO 4 mm eyepiece with 80 degree field of view\" 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\/2026\/01\/Omegon-Oculair-OGDO-4mm-80d.jpg\" alt=\"Omegon OGDO 4 mm eyepiece with 80 degree field of view\" 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\">Lanthaan-ED glass from Ohara<\/h4>\n\n\n\n<p class=\"wp-block-paragraph\">The heart of the OGDO series is lanthanum-holding ED glass from Japanese glass manufacturer Ohara. Color aberrations are minimized, and the image remains sharp to the edge of the wide field, even with fast telescopes down to f\/4.5.<\/p>\n\n\n\n<p class=\"wp-block-paragraph\">For very fast Newtonians around f\/4.5 and faster, the manufacturer recommends a coma corrector to keep the outer edges sharp as well; that's a characteristic of the telescope, not the eyepiece.<\/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\/2026\/01\/Omegon-Oculair-OGDO-4mm-80d-2.jpg\" alt=\"Omegon OGDO 4 mm eyepiece with 80 degree field of view\" 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\">80 degrees with 20 mm eye relief<\/h4>\n\n\n\n<p class=\"wp-block-paragraph\">The combination of an ultra-wide field of view and generous eye relief is rare: eyeglass wearers can see the full 80-degree field of view without taking off their glasses. The rotating eyecup can be continuously adjusted to your personal viewing distance.<\/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\/2026\/01\/Omegon-Oculair-OGDO-4mm-80d-1.jpg\" alt=\"Omegon OGDO 4 mm eyepiece with 80 degree field of view\" 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\">Metal casing, ready for any night<\/h4>\n\n\n\n<p class=\"wp-block-paragraph\">Water and dust proof: dew and temperature changes won't affect the optics. This is an eyepiece built to last for years.<\/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\/2026\/01\/Omegon-Oculair-OGDO-4mm-80d-3.jpg\" alt=\"Omegon OGDO 4 mm eyepiece with 80 degree field of view\" 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\">What do you see with 4 mm?<\/h4>\n\n\n\n<p class=\"wp-block-paragraph\">On a 200\/1200 Dobson, 4 mm gives a magnification of 300x: only useful in calm air and with sufficient aperture (maximum 2x the aperture in millimeters). On a 100\/580 refractor, 145x is actually a daily working magnification.<\/p>\n\n\n\n<p class=\"wp-block-paragraph\">Nice lunar structure, the Cassini division and close binary stars, floating in an 80 degree field.<\/p>\n<\/div>\n<\/div>\n\n\n\n<h3 class=\"wp-block-heading\">Included<\/h3>\n\n\n\n<ul class=\"wp-block-list\"><li>Omegon OGDO 4 mm eyepiece<\/li><li>Flannel storage bag<\/li><li>Lens and eyepiece covers<\/li><\/ul>\n\n\n\n<h3 class=\"wp-block-heading\">Featured accessories<\/h3>\n\n\n\n<p class=\"wp-block-paragraph\">The OGDO series ranges from 4 to 20 mm with the same field of view and eye relief. The OGDO eyecup set M50 is the matching replacement and comfort accessory.<\/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 Demanding observers who want top-level edge sharpness and color purity<\/li><li>\u2713 Spectacle wearers: the full 80-degree field of view remains visible thanks to a 20 mm eye relief<\/li><li>\u2713 Owners of fast telescopes from f\/4.5<\/li><li>\u2717 Those looking for a light eyepiece for a small table-top telescope: these are sturdy metal eyepieces<\/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>Focal length<\/strong><\/td><td>4 mm<\/td><\/tr><tr><td><strong>Apparent field of view<\/strong><\/td><td>80 degrees<\/td><\/tr><tr><td><strong>Eye relief<\/strong><\/td><td>20 mm<\/td><\/tr><tr><td><strong>Optical design<\/strong><\/td><td>Lanthanum-ED-Glass (Ohara), multilayer coated<\/td><\/tr><tr><td><strong>Housing<\/strong><\/td><td>full metal, waterproof, and dustproof<\/td><\/tr><tr><td><strong>Mount<\/strong><\/td><td>1.25 and 2 inch, with filter thread<\/td><\/tr><tr><td><strong>Eyecup<\/strong><\/td><td>swivel adjustable<\/td><\/tr><tr><td><strong>Series<\/strong><\/td><td>Omegon OGDO 80\u00b0<\/td><\/tr><\/tbody><\/table><\/figure>\n\n\n\n<p class=\"wp-block-paragraph\">You can find more accessories for this brand at the <a href=\"\/en\/brands\/omegon\/\">Omegon brand page<\/a>.<\/p>","protected":false},"excerpt":{"rendered":"<p>The Omegon OGDO 4 mm eyepiece (1.25 and 2 inch) combines Ohara's lanthanum ED glass with a 80-degree field of view and a 20 mm eye distance. Waterproof metal housing, including carrying bag and caps.<\/p>","protected":false},"featured_media":98865,"comment_status":"open","ping_status":"closed","template":"","meta":{"_acf_changed":false},"product_brand":[126],"product_cat":[3131,3129,56],"product_tag":[],"class_list":["post-92489","product","type-product","status-publish","has-post-thumbnail","product_brand-omegon","product_cat-groothoek-oculairen-wide-field","product_cat-oculairs-en-barlows","product_cat-telescoop-accessoires","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":[92421],"acf":[],"jetpack_sharing_enabled":true,"jetpack-related-posts":[{"id":111636,"url":"https:\/\/www.telescoop.nl\/en\/zwo-seestar-s50-pro\/","url_meta":{"origin":92489,"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\/92489","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=92489"}],"wp:featuredmedia":[{"embeddable":true,"href":"https:\/\/www.telescoop.nl\/en\/wp-json\/wp\/v2\/media\/98865"}],"wp:attachment":[{"href":"https:\/\/www.telescoop.nl\/en\/wp-json\/wp\/v2\/media?parent=92489"}],"wp:term":[{"taxonomy":"product_brand","embeddable":true,"href":"https:\/\/www.telescoop.nl\/en\/wp-json\/wp\/v2\/product_brand?post=92489"},{"taxonomy":"product_cat","embeddable":true,"href":"https:\/\/www.telescoop.nl\/en\/wp-json\/wp\/v2\/product_cat?post=92489"},{"taxonomy":"product_tag","embeddable":true,"href":"https:\/\/www.telescoop.nl\/en\/wp-json\/wp\/v2\/product_tag?post=92489"}],"curies":[{"name":"wp","href":"https:\/\/api.w.org\/{rel}","templated":true}]}}