{"id":29253,"date":"2025-09-22T22:31:38","date_gmt":"2025-09-22T20:31:38","guid":{"rendered":"https:\/\/www.telescoop.nl\/?post_type=product&#038;p=29253"},"modified":"2026-08-23T15:12:24","modified_gmt":"2026-08-23T13:12:24","slug":"bresser-eyepiece-kellner-4mm-125","status":"publish","type":"product","link":"https:\/\/www.telescoop.nl\/en\/bresser-oculair-kellner-4mm-125\/","title":{"rendered":"Bresser Kellner Eyepiece 4mm 1.25\u2033"},"content":{"rendered":"<h2 class=\"wp-block-heading has-text-align-center\"><strong>Bresser Kellner Eyepiece 4mm 1.25\u2033: very high magnification for clear nights<\/strong><\/h2>\n\n\n\n<p class=\"wp-block-paragraph\">The Bresser Kellner 4mm is a short-focus eyepiece with three lenses. With a 4mm (0.16 inch) focal length, you can achieve very high magnifications with your telescope, for example for lunar craters or the disk of Jupiter.<\/p>\n\n\n\n<p class=\"wp-block-paragraph\">Be honest about the expectations: the field of view is narrow and the eye relief is short. Such high magnifications only work with steady air and on telescopes with sufficient aperture. As a main eyepiece for planets, a Pl\u00f6ssl with a longer focal length plus a Barlow lens is usually more comfortable.<\/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\/09\/Bresser-Oculair-Kellner-4mm-1-25-.jpg\" alt=\"Bresser Kellner eyepiece 4 mm 1.25 inch\" title=\"\"><\/figure><figure class=\"wp-block-image\"><img decoding=\"async\" src=\"https:\/\/www.telescoop.nl\/wp-content\/uploads\/2025\/09\/Bresser-Oculair-Kellner-4mm-1-25-1.jpg\" alt=\"Bresser Kellner eyepiece 4 mm 1.25 inch\" title=\"\"><\/figure><figure class=\"wp-block-image\"><img decoding=\"async\" src=\"https:\/\/www.telescoop.nl\/wp-content\/uploads\/2025\/09\/Bresser-Oculair-Kellner-4mm-1-25-2.jpg\" alt=\"Bresser Kellner eyepiece 4 mm 1.25 inch\" title=\"\"><\/figure><\/figure>\n\n\n\n<h3 class=\"wp-block-heading\">Features<\/h3>\n\n\n\n<ul class=\"wp-block-list\"><li>Very high magnification for Moon and planets with good seeing<\/li><li>Three coated lenses in a classic Kellner design<\/li><li>Compact 1.25 inch metal mount<\/li><li>Affordable way to explore the upper limit of your telescope<\/li><\/ul>\n\n\n\n<h3 class=\"wp-block-heading\">Compatibility<\/h3>\n\n\n\n<p class=\"wp-block-paragraph\">Fits 1.25 inch (31.7 mm) focusers. Consider the realistic maximum magnification of your telescope: about twice the aperture in millimeters. On a 130 mm telescope with a 650 mm focal length, this eyepiece provides 163x, which is well usable. On small table-top telescopes, the image quickly becomes too dim.<\/p>\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>Optical design<\/strong><\/td><td>Waiter, 3 lenses<\/td><\/tr><tr><td><strong>Apparent field of view<\/strong><\/td><td>approx. 40 degrees<\/td><\/tr><tr><td><strong>Coating<\/strong><\/td><td>Coated lenses<\/td><\/tr><tr><td><strong>Mount<\/strong><\/td><td>1.25 inches (31.7 mm)<\/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\/bresser\/\">Bresser 1TP5 Page<\/a>.<\/p>","protected":false},"excerpt":{"rendered":"<p>Bresser Kellner eyepiece 4 mm for very high magnifications on the Moon and planets. Three coated lenses, 1.25 inch barrel.<\/p>","protected":false},"featured_media":29255,"comment_status":"open","ping_status":"closed","template":"","meta":{"_acf_changed":false},"product_brand":[128],"product_cat":[3130,589,56],"product_tag":[],"class_list":["post-29253","product","type-product","status-publish","has-post-thumbnail","product_brand-bresser","product_cat-oculairen-standaard-gezichtsveld","product_cat-optische-accessoires-v1","product_cat-telescoop-accessoires","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":32361,"url":"https:\/\/www.telescoop.nl\/en\/bresser-kellner-oculair-10mm-1-25-inch\/","url_meta":{"origin":29253,"position":0},"title":"Bresser Kellner eyepiece 10mm 1.25 inches","author":"","date":"02-11-2025","format":false,"excerpt":"Bresser Kellner 10 mm eyepiece with three coated lenses and rubber eyecup. Affordable replacement or addition, 1.25-inch barrel.","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\/Bresser-Oculair-Kellner-10mm-125-1.jpg?resize=350%2C200&ssl=1","width":350,"height":200},"classes":[]},{"id":32346,"url":"https:\/\/www.telescoop.nl\/en\/bresser-kellner-oculair-20mm-1-25-inch\/","url_meta":{"origin":29253,"position":1},"title":"Bresser Kellner eyepiece 20mm 1.25 inches","author":"","date":"02-11-2025","format":false,"excerpt":"Bresser Kellner 20 mm eyepiece with three coated lenses and rubber eyecup. Affordable replacement or addition, 1.25-inch barrel.","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\/Bresser-Oculair-Kellner-20mm-125-1.jpg?resize=350%2C200&ssl=1","width":350,"height":200},"classes":[]},{"id":29243,"url":"https:\/\/www.telescoop.nl\/en\/bresser-oculair-plossl-pl-5mm-1-25\/","url_meta":{"origin":29253,"position":2},"title":"Bresser Pl\u00f6ssl Eyepiece 5mm 1.25\u2033","author":"Info telescoop","date":"22-09-2025","format":false,"excerpt":"Bresser Plossl 5mm eyepiece with four fully multi-coated lenses, 50-degree field of view, metal housing, and filter thread. 1.25-inch barrel.","rel":"","context":"With 1 comment","block_context":{"text":"With 1 comment","link":"https:\/\/www.telescoop.nl\/en\/bresser-oculair-plossl-pl-5mm-1-25\/#comments"},"img":{"alt_text":"Bresser Oculair Pl\u00f6ssl PL 5mm 1,25\"","src":"https:\/\/i0.wp.com\/www.telescoop.nl\/wp-content\/uploads\/2025\/09\/Bresser-Oculair-Ploessl-PL-5mm-1-25-.jpg?resize=350%2C200&ssl=1","width":350,"height":200,"srcset":"https:\/\/i0.wp.com\/www.telescoop.nl\/wp-content\/uploads\/2025\/09\/Bresser-Oculair-Ploessl-PL-5mm-1-25-.jpg?resize=350%2C200&ssl=1 1x, https:\/\/i0.wp.com\/www.telescoop.nl\/wp-content\/uploads\/2025\/09\/Bresser-Oculair-Ploessl-PL-5mm-1-25-.jpg?resize=525%2C300&ssl=1 1.5x, https:\/\/i0.wp.com\/www.telescoop.nl\/wp-content\/uploads\/2025\/09\/Bresser-Oculair-Ploessl-PL-5mm-1-25-.jpg?resize=700%2C400&ssl=1 2x, https:\/\/i0.wp.com\/www.telescoop.nl\/wp-content\/uploads\/2025\/09\/Bresser-Oculair-Ploessl-PL-5mm-1-25-.jpg?resize=1050%2C600&ssl=1 3x, https:\/\/i0.wp.com\/www.telescoop.nl\/wp-content\/uploads\/2025\/09\/Bresser-Oculair-Ploessl-PL-5mm-1-25-.jpg?resize=1400%2C800&ssl=1 4x"},"classes":[]},{"id":7611,"url":"https:\/\/www.telescoop.nl\/en\/bresser-messier-n-130-650-dobson\/","url_meta":{"origin":29253,"position":3},"title":"Bresser Messier N 130\/650 - 130mm Dobson","author":"Info telescoop","date":"12-02-2025","format":false,"excerpt":"The Bresser Messier N 130\/650 Dobson comes with 130 mm Newton optics, a table-top Dobson mount, 25 mm and 9 mm Kellner eyepieces, an LED red dot finder, a moon filter, and an objective solar filter. Ready to use in just a few minutes.","rel":"","context":"Similar post","block_context":{"text":"Similar post","link":""},"img":{"alt_text":"bresser dobson 130 650","src":"https:\/\/i0.wp.com\/www.telescoop.nl\/wp-content\/uploads\/2025\/02\/Bresser-Dobson-telescoop-N-130-650-Messier-DOB.jpg?resize=350%2C200&ssl=1","width":350,"height":200,"srcset":"https:\/\/i0.wp.com\/www.telescoop.nl\/wp-content\/uploads\/2025\/02\/Bresser-Dobson-telescoop-N-130-650-Messier-DOB.jpg?resize=350%2C200&ssl=1 1x, https:\/\/i0.wp.com\/www.telescoop.nl\/wp-content\/uploads\/2025\/02\/Bresser-Dobson-telescoop-N-130-650-Messier-DOB.jpg?resize=525%2C300&ssl=1 1.5x, https:\/\/i0.wp.com\/www.telescoop.nl\/wp-content\/uploads\/2025\/02\/Bresser-Dobson-telescoop-N-130-650-Messier-DOB.jpg?resize=700%2C400&ssl=1 2x, https:\/\/i0.wp.com\/www.telescoop.nl\/wp-content\/uploads\/2025\/02\/Bresser-Dobson-telescoop-N-130-650-Messier-DOB.jpg?resize=1050%2C600&ssl=1 3x, https:\/\/i0.wp.com\/www.telescoop.nl\/wp-content\/uploads\/2025\/02\/Bresser-Dobson-telescoop-N-130-650-Messier-DOB.jpg?resize=1400%2C800&ssl=1 4x"},"classes":[]},{"id":29247,"url":"https:\/\/www.telescoop.nl\/en\/bresser-oculair-plossl-pl-10mm-125\/","url_meta":{"origin":29253,"position":4},"title":"Bresser Pl\u00f6ssl Eyepiece 10mm 1.25\u2033","author":"Info telescoop","date":"22-09-2025","format":false,"excerpt":"Bresser Pl\u00f6ssl 10mm eyepiece with four fully multi-coated lenses, 50-degree field of view, metal housing, and filter thread. 1.25-inch fitting.","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\/09\/Bresser-Oculair-Ploessl-PL-10mm-1-25-.jpg?resize=350%2C200&ssl=1","width":350,"height":200,"srcset":"https:\/\/i0.wp.com\/www.telescoop.nl\/wp-content\/uploads\/2025\/09\/Bresser-Oculair-Ploessl-PL-10mm-1-25-.jpg?resize=350%2C200&ssl=1 1x, https:\/\/i0.wp.com\/www.telescoop.nl\/wp-content\/uploads\/2025\/09\/Bresser-Oculair-Ploessl-PL-10mm-1-25-.jpg?resize=525%2C300&ssl=1 1.5x, https:\/\/i0.wp.com\/www.telescoop.nl\/wp-content\/uploads\/2025\/09\/Bresser-Oculair-Ploessl-PL-10mm-1-25-.jpg?resize=700%2C400&ssl=1 2x, https:\/\/i0.wp.com\/www.telescoop.nl\/wp-content\/uploads\/2025\/09\/Bresser-Oculair-Ploessl-PL-10mm-1-25-.jpg?resize=1050%2C600&ssl=1 3x, https:\/\/i0.wp.com\/www.telescoop.nl\/wp-content\/uploads\/2025\/09\/Bresser-Oculair-Ploessl-PL-10mm-1-25-.jpg?resize=1400%2C800&ssl=1 4x"},"classes":[]},{"id":7612,"url":"https:\/\/www.telescoop.nl\/en\/bresser-messier-n-150-750-dobson\/","url_meta":{"origin":29253,"position":5},"title":"Bresser Messier N 150\/750 - 150mm Dobson","author":"Info telescoop","date":"12-02-2025","format":false,"excerpt":"The Bresser Messier N 150\/750 Dobson comes with a 150 mm parabolic Newtonian mirror, compact Dobson mount, 25 mm and 9 mm Kellner eyepieces, LED red dot finder, moon filter, and objective solar filter.","rel":"","context":"With 1 comment","block_context":{"text":"With 1 comment","link":"https:\/\/www.telescoop.nl\/en\/bresser-messier-n-150-750-dobson\/#comments"},"img":{"alt_text":"bresser dobson 150-750","src":"https:\/\/i0.wp.com\/www.telescoop.nl\/wp-content\/uploads\/2025\/02\/Bresser-Dobson-telescoop-N-150-750-Messier-DOB.jpg?resize=350%2C200&ssl=1","width":350,"height":200,"srcset":"https:\/\/i0.wp.com\/www.telescoop.nl\/wp-content\/uploads\/2025\/02\/Bresser-Dobson-telescoop-N-150-750-Messier-DOB.jpg?resize=350%2C200&ssl=1 1x, https:\/\/i0.wp.com\/www.telescoop.nl\/wp-content\/uploads\/2025\/02\/Bresser-Dobson-telescoop-N-150-750-Messier-DOB.jpg?resize=525%2C300&ssl=1 1.5x, https:\/\/i0.wp.com\/www.telescoop.nl\/wp-content\/uploads\/2025\/02\/Bresser-Dobson-telescoop-N-150-750-Messier-DOB.jpg?resize=700%2C400&ssl=1 2x, https:\/\/i0.wp.com\/www.telescoop.nl\/wp-content\/uploads\/2025\/02\/Bresser-Dobson-telescoop-N-150-750-Messier-DOB.jpg?resize=1050%2C600&ssl=1 3x, https:\/\/i0.wp.com\/www.telescoop.nl\/wp-content\/uploads\/2025\/02\/Bresser-Dobson-telescoop-N-150-750-Messier-DOB.jpg?resize=1400%2C800&ssl=1 4x"},"classes":[]}],"_links":{"self":[{"href":"https:\/\/www.telescoop.nl\/en\/wp-json\/wp\/v2\/product\/29253","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=29253"}],"wp:featuredmedia":[{"embeddable":true,"href":"https:\/\/www.telescoop.nl\/en\/wp-json\/wp\/v2\/media\/29255"}],"wp:attachment":[{"href":"https:\/\/www.telescoop.nl\/en\/wp-json\/wp\/v2\/media?parent=29253"}],"wp:term":[{"taxonomy":"product_brand","embeddable":true,"href":"https:\/\/www.telescoop.nl\/en\/wp-json\/wp\/v2\/product_brand?post=29253"},{"taxonomy":"product_cat","embeddable":true,"href":"https:\/\/www.telescoop.nl\/en\/wp-json\/wp\/v2\/product_cat?post=29253"},{"taxonomy":"product_tag","embeddable":true,"href":"https:\/\/www.telescoop.nl\/en\/wp-json\/wp\/v2\/product_tag?post=29253"}],"curies":[{"name":"wp","href":"https:\/\/api.w.org\/{rel}","templated":true}]}}