{"product_id":"svbony-4mm-58-degree-planetary-eyepiece-w2488a","title":"SVBONY 4mm 58° Planetary Eyepiece – 1.25″ (W2488A)","description":"\u003cp\u003eThe \u003cstrong\u003eSVBONY 4mm 58° Planetary Eyepiece (W2488A)\u003c\/strong\u003e is a fixed focal length, 1.25″ eyepiece for high magnification views of the Moon, planets and suitable compact targets. Its 58° apparent field of view and 15mm eye relief offer a practical combination of viewing space and eye clearance.\u003c\/p\u003e\n\u003cp\u003e\u003cimg src=\"https:\/\/cdn.shopify.com\/s\/files\/1\/0523\/1650\/4241\/files\/w2488a_20250807092731_9732.jpg?v=1793910672\" alt=\"SVBONY W2488A 4mm planetary eyepiece with black body, rubber eyecup and silver 1.25-inch barrel\" loading=\"lazy\"\u003e\u003c\/p\u003e\n\u003ch2\u003eHigh magnification for lunar and planetary observing\u003c\/h2\u003e\n\u003cp\u003eA 4mm eyepiece gives high magnification without adding a Barlow lens. Use it to examine lunar features, planetary detail or close double stars when your telescope and atmospheric conditions support the resulting power. Start with a longer focal length eyepiece to locate and centre the target, then change to the 4mm for a closer view.\u003c\/p\u003e\n\u003cp\u003eMagnification is calculated by dividing your telescope’s focal length by 4mm. For example, a 600mm telescope gives \u003cstrong\u003e150×\u003c\/strong\u003e, while a 1,000mm telescope gives \u003cstrong\u003e250×\u003c\/strong\u003e. These are calculated examples, not guaranteed useful magnifications: aperture, optical alignment, cooling and atmospheric steadiness all affect the view.\u003c\/p\u003e\n\u003ch2\u003eComfortable viewing and contrast-focused construction\u003c\/h2\u003e\n\u003cul\u003e\n\u003cli\u003e\n\u003cstrong\u003e58° apparent field:\u003c\/strong\u003e provides viewing space around the target at high power.\u003c\/li\u003e\n\u003cli\u003e\n\u003cstrong\u003e15mm eye relief:\u003c\/strong\u003e the manufacturer’s specified viewing distance from the eye lens, with a fold-down rubber eyecup for positioning your eye.\u003c\/li\u003e\n\u003cli\u003e\n\u003cstrong\u003eFive-element optical design:\u003c\/strong\u003e with fully multi-coated lenses.\u003c\/li\u003e\n\u003cli\u003e\n\u003cstrong\u003eBlackened lens edges and internal anti-reflection threads:\u003c\/strong\u003e help control stray light.\u003c\/li\u003e\n\u003cli\u003e\n\u003cstrong\u003eSafety undercut:\u003c\/strong\u003e on the barrel, used with a properly tightened eyepiece holder.\u003c\/li\u003e\n\u003cli\u003e\n\u003cstrong\u003eFilter-ready barrel:\u003c\/strong\u003e accepts compatible standard 1.25″ eyepiece filters.\u003c\/li\u003e\n\u003c\/ul\u003e\n\u003ch2\u003eCompatibility and choosing the right power\u003c\/h2\u003e\n\u003cp\u003eFits telescope focusers and diagonals with a standard \u003cstrong\u003e1.25″ eyepiece holder\u003c\/strong\u003e. A 2″ holder requires a suitable 2″ to 1.25″ adapter. Check that the magnification produced by a 4mm eyepiece is appropriate for your telescope; on long focal length instruments it can be too high for typical seeing. This is a fixed 4mm eyepiece, not a zoom.\u003c\/p\u003e\n\u003ch2\u003eSpecifications\u003c\/h2\u003e\n\u003ctable\u003e\u003ctbody\u003e\n\u003ctr\u003e\n\u003cth scope=\"row\"\u003eBrand \/ SKU\u003c\/th\u003e\n\u003ctd\u003eSVBONY \/ W2488A\u003c\/td\u003e\n\u003c\/tr\u003e\n\u003ctr\u003e\n\u003cth scope=\"row\"\u003eFocal length\u003c\/th\u003e\n\u003ctd\u003e4mm, fixed\u003c\/td\u003e\n\u003c\/tr\u003e\n\u003ctr\u003e\n\u003cth scope=\"row\"\u003eApparent field of view\u003c\/th\u003e\n\u003ctd\u003e58°\u003c\/td\u003e\n\u003c\/tr\u003e\n\u003ctr\u003e\n\u003cth scope=\"row\"\u003eBarrel size\u003c\/th\u003e\n\u003ctd\u003e1.25″\u003c\/td\u003e\n\u003c\/tr\u003e\n\u003ctr\u003e\n\u003cth scope=\"row\"\u003eEye relief\u003c\/th\u003e\n\u003ctd\u003e15mm\u003c\/td\u003e\n\u003c\/tr\u003e\n\u003ctr\u003e\n\u003cth scope=\"row\"\u003eEye lens diameter\u003c\/th\u003e\n\u003ctd\u003e21mm\u003c\/td\u003e\n\u003c\/tr\u003e\n\u003ctr\u003e\n\u003cth scope=\"row\"\u003eOptical elements\u003c\/th\u003e\n\u003ctd\u003e5\u003c\/td\u003e\n\u003c\/tr\u003e\n\u003ctr\u003e\n\u003cth scope=\"row\"\u003eCoatings\u003c\/th\u003e\n\u003ctd\u003eFully multi-coated\u003c\/td\u003e\n\u003c\/tr\u003e\n\u003ctr\u003e\n\u003cth scope=\"row\"\u003eEyecup\u003c\/th\u003e\n\u003ctd\u003eFold-down rubber\u003c\/td\u003e\n\u003c\/tr\u003e\n\u003ctr\u003e\n\u003cth scope=\"row\"\u003eFilter fitting\u003c\/th\u003e\n\u003ctd\u003eStandard 1.25″ eyepiece filter thread\u003c\/td\u003e\n\u003c\/tr\u003e\n\u003ctr\u003e\n\u003cth scope=\"row\"\u003eNet weight\u003c\/th\u003e\n\u003ctd\u003e160g\u003c\/td\u003e\n\u003c\/tr\u003e\n\u003c\/tbody\u003e\u003c\/table\u003e\n\u003ch2\u003eWhat’s included\u003c\/h2\u003e\u003cul\u003e\n\u003cli\u003eSVBONY W2488A 4mm 58° planetary eyepiece\u003c\/li\u003e\n\u003cli\u003eLens caps for both ends\u003c\/li\u003e\n\u003c\/ul\u003e\n\u003ch2\u003eExplore other focal lengths\u003c\/h2\u003e\u003cp\u003eBrowse our \u003ca href=\"\/collections\/svbony-eyepieces\"\u003eSVBONY telescope eyepieces\u003c\/a\u003e to choose lower powers for finding targets and observing wider fields.\u003c\/p\u003e","brand":"SVBONY","offers":[{"title":"Default Title","offer_id":55727108653432,"sku":"W2488A","price":39.99,"currency_code":"GBP","in_stock":true}],"thumbnail_url":"\/\/cdn.shopify.com\/s\/files\/1\/0523\/1650\/4241\/files\/w2488a_20250807092731_9732.jpg?v=1793910672","url":"https:\/\/www.darkclearskies.co.uk\/products\/svbony-4mm-58-degree-planetary-eyepiece-w2488a","provider":"Dark Clear Skies ","version":"1.0","type":"link"}