{"product_id":"explore-scientific-72-degree-ed-40mm-waterproof-eyepiece","title":"Explore Scientific 72° ED Series 40mm Waterproof Eyepiece","description":"\u003cp\u003ePlössl and Kellner eyepieces shipped with most telescopes get the job done, but they leave performance on the table — narrow apparent fields, limited eye relief, and visible chromatic aberration at the field edge. The Explore Scientific 72° ED Series 40mm Waterproof Eyepiece is a \u003cstrong\u003egenuine HOYA FCD1 extra-low dispersion glass eyepiece with a 72° apparent field of view, waterproof argon-purged construction, and long eye relief\u003c\/strong\u003e — a meaningful optical upgrade that transforms what you see through your telescope.\u003c\/p\u003e\n\u003cp\u003eThe FCD1 ED glass sharply reduces chromatic aberration compared to standard eyepiece designs, producing cleaner star points and higher contrast across the field. The 72° apparent field of view is wide enough to create a panoramic, immersive viewing experience without the weight and expense of ultra-wide designs. Argon purging prevents internal fogging in humid conditions, and the waterproof housing means dew-soaked nights won't damage the optics.\u003c\/p\u003e\n\u003chr\u003e\n\u003ch5 id=\"key-features\"\u003eKey Features\u003c\/h5\u003e\n\u003cul\u003e\n\u003cli\u003e\n\u003cstrong\u003eHOYA FCD1 extra-low dispersion glass\u003c\/strong\u003e — reduced chromatic aberration for sharper, higher-contrast views\u003c\/li\u003e\n\u003cli\u003e\n\u003cstrong\u003e72° apparent field of view\u003c\/strong\u003e — immersive wide-field viewing without tunnel vision\u003c\/li\u003e\n\u003cli\u003e\n\u003cstrong\u003eWaterproof and argon-purged\u003c\/strong\u003e — sealed against moisture, fog-proof in all conditions\u003c\/li\u003e\n\u003cli\u003e\n\u003cstrong\u003eLong eye relief\u003c\/strong\u003e — comfortable extended viewing for both eyeglass wearers and unaided observers\u003c\/li\u003e\n\u003cli\u003e\n\u003cstrong\u003e2\" barrel\u003c\/strong\u003e — wider format for maximum light throughput and field stop diameter\u003c\/li\u003e\n\u003cli\u003e\n\u003cstrong\u003eEnhanced multi-layer deposition coatings\u003c\/strong\u003e on all air-to-glass surfaces for maximum light transmission\u003c\/li\u003e\n\u003c\/ul\u003e\n\u003chr\u003e\n\u003ch5 id=\"ideal-for\"\u003eIdeal For\u003c\/h5\u003e\n\u003cp\u003e\u003cstrong\u003eMaximum field, minimum magnification — designed for the widest possible views through fast-ratio telescopes\u003c\/strong\u003e. An excellent upgrade from stock Plössl eyepieces for observers who want wider fields, better eye relief, and the optical clarity that ED glass provides. Compatible with any telescope accepting 2\" eyepieces.\u003c\/p\u003e","brand":"Explore Scientific","offers":[{"title":"Default Title","offer_id":47709679583406,"sku":"EPWP7240ED-01","price":449.0,"currency_code":"USD","in_stock":true}],"thumbnail_url":"\/\/cdn.shopify.com\/s\/files\/1\/0620\/2494\/1742\/files\/EPWP7240ED-01.jpg?v=1775598490","url":"https:\/\/astrotelescopium.com\/products\/explore-scientific-72-degree-ed-40mm-waterproof-eyepiece","provider":"AstroTelescopium","version":"1.0","type":"link"}