{"product_id":"explore-scientific-epwp7225ed-01","title":"Explore Scientific 72° ED Series 25mm Waterproof Eyepiece","description":"\u003cul class=\"DAV-feature-list\"\u003e\n\u003cli\u003e25mm Focal Length\u003c\/li\u003e\n\u003cli\u003e72° Apparent Field of View\u003c\/li\u003e\n\u003cli\u003e2-Inch Barrel Diameter\u003c\/li\u003e\n\u003cli\u003eExtra-Low Dispersion (ED) Glass\u003c\/li\u003e\n\u003cli\u003eWaterproof and Gas-Purged Construction\u003c\/li\u003e\n\u003c\/ul\u003e\n\u003c!-- more --\u003e\n\u003cul class=\"tabs\"\u003e\n\u003cli class=\"active\"\u003eDescription\u003c\/li\u003e\n\u003cli\u003eFAQ\u003c\/li\u003e\n\u003cli\u003eSpecifications\u003c\/li\u003e\n\u003cli\u003eIn the Box\u003c\/li\u003e\n\u003cli\u003eDownloads\u003c\/li\u003e\n\u003cli\u003eWarranty\u003c\/li\u003e\n\u003c\/ul\u003e\n\u003cul class=\"tabs-content\"\u003e\n\u003cli class=\"active\"\u003e\n\u003cdiv\u003e\n  \u003cdiv class=\"DAV-bg-light\"\u003e\n    \u003cdiv class=\"DAV-section-center\"\u003e\n      \u003ch2\u003e72° ED Series 25mm Waterproof Eyepiece\u003c\/h2\u003e\n      \u003cp\u003eThe Explore Scientific 72° ED Series 25mm Waterproof Eyepiece uses a 2-inch barrel to deliver expansive, low-power views of the night sky. Its 72° apparent field of view is designed to fully contain large deep-sky objects, while the 25mm focal length produces bright images perfect for sweeping through rich star fields like the Milky Way.\u003c\/p\u003e\n    \u003c\/div\u003e\n  \u003c\/div\u003e\n\n  \u003cdiv class=\"DAV-bg-light\"\u003e\n    \u003cdiv class=\"DAV-section\"\u003e\n      \u003ch3\u003eThe 72° Field: Low-Power, Immersive Views\u003c\/h3\u003e\n      \u003cp\u003eWith a 25mm focal length, this eyepiece provides low magnification, which brightens the image and widens the true field of view in your telescope. The 72° apparent field creates an immersive \"spacewalk\" effect, making it easier to frame large targets like the Andromeda Galaxy (M31) or the North American Nebula (NGC 7000) in their entirety.\u003c\/p\u003e\n    \u003c\/div\u003e\n  \u003c\/div\u003e\n\n    \u003cdiv class=\"DAV-bg-light\"\u003e\n    \u003cdiv class=\"DAV-section\"\u003e\n      \u003ch3\u003eED Glass Optics in a 2-Inch Barrel\u003c\/h3\u003e\n      \u003cp\u003eThis eyepiece incorporates Extra-Low Dispersion (ED) glass to minimize chromatic aberration, or false color fringing, which is especially critical in a wide-field design. This results in sharper star points, higher contrast, and more natural color rendition across the entire 72° field. The 2-inch barrel format allows for a larger internal field stop than a 1.25-inch eyepiece, preventing vignetting and ensuring the view is bright to the edge.\u003c\/p\u003e\n    \u003c\/div\u003e\n  \u003c\/div\u003e\n\n  \u003cdiv class=\"DAV-bg-light\"\u003e\n    \u003cdiv class=\"DAV-section\"\u003e\n        \u003ch3\u003eWaterproof Construction and Comfortable Eye Relief\u003c\/h3\u003e\n        \u003cp\u003eThe eyepiece body is argon-purged and sealed, making it fully waterproof. This prevents internal fogging during nights with heavy dew and protects the internal lens coatings from moisture and fungus over the long term. Generous eye relief allows for comfortable viewing sessions without needing to press your eye right up against the lens, a significant benefit for all observers.\u003c\/p\u003e\n    \u003c\/div\u003e\n  \u003c\/div\u003e\n  \n  \u003cdiv class=\"DAV-bg-light\"\u003e\n    \u003cdiv class=\"DAV-section\"\u003e\n      \u003ch3\u003eExplore Scientific 72° 25mm vs. a Standard 25mm Plössl\u003c\/h3\u003e\n      \u003cp\u003eCompared to a traditional 25mm Plössl eyepiece, the Explore Scientific 72° ED offers two primary advantages.\u003c\/p\u003e\n      \u003cul\u003e\n        \u003cli\u003e\n\u003cstrong\u003eWider Apparent Field:\u003c\/strong\u003e A standard Plössl typically has a 50-52° apparent field. The 72° field of this eyepiece shows a significantly larger area of sky at the same magnification, making it easier to find and frame objects.\u003c\/li\u003e\n        \u003cli\u003e\n\u003cstrong\u003eSuperior Color Correction:\u003c\/strong\u003e The ED glass in the Explore Scientific design provides a noticeable reduction in chromatic aberration. On bright targets like Jupiter or the lunar limb, the view through the 72° ED eyepiece will show minimal to no color fringing, while a standard Plössl may exhibit a slight purplish or yellowish halo.\u003c\/li\u003e\n      \u003c\/ul\u003e\n    \u003c\/div\u003e\n  \u003c\/div\u003e\n\n\u003c\/div\u003e\n\u003c\/li\u003e\n\n\u003cli\u003e\n  \u003cdiv class=\"DAV-accordion\"\u003e\n    \u003ch3 class=\"DAV-accordion-Q\"\u003eWhat is the main advantage of the Explore Scientific 72° 25mm eyepiece's 2-inch barrel?\u003c\/h3\u003e\n  \u003c\/div\u003e\n  \u003cdiv class=\"DAV-accordion-A\"\u003e\n    \u003cp\u003eThe \u003cstrong\u003e2-inch barrel\u003c\/strong\u003e allows for a larger physical field stop inside the eyepiece. This is essential for achieving a wide 72° apparent field of view at a long 25mm focal length without causing the edges of the view to dim or be cut off (vignetting).\u003c\/p\u003e\n  \u003c\/div\u003e\n  \u003cdiv class=\"DAV-accordion\"\u003e\n    \u003ch3 class=\"DAV-accordion-Q\"\u003eHow does the ED glass in the 72° 25mm eyepiece improve views?\u003c\/h3\u003e\n  \u003c\/div\u003e\n  \u003cdiv class=\"DAV-accordion-A\"\u003e\n    \u003cp\u003e\u003cstrong\u003eExtra-Low Dispersion (ED) glass\u003c\/strong\u003e corrects for chromatic aberration. This means it focuses all colors of light to the same point, resulting in sharper stars, higher contrast, and the elimination of distracting purple or yellow color fringing around bright objects like planets and bright stars.\u003c\/p\u003e\n  \u003c\/div\u003e\n    \u003cdiv class=\"DAV-accordion\"\u003e\n    \u003ch3 class=\"DAV-accordion-Q\"\u003eIs the Explore Scientific 72° 25mm eyepiece good for observers who wear glasses?\u003c\/h3\u003e\n  \u003c\/div\u003e\n  \u003cdiv class=\"DAV-accordion-A\"\u003e\n    \u003cp\u003eYes. The eyepiece is designed with generous eye relief, which means you can hold your eye at a comfortable distance from the lens and still see the entire 72° field of view. This makes it much more comfortable for eyeglass wearers.\u003c\/p\u003e\n  \u003c\/div\u003e\n  \u003cdiv class=\"DAV-accordion\"\u003e\n    \u003ch3 class=\"DAV-accordion-Q\"\u003eWhy is a waterproof eyepiece like the 72° ED 25mm useful?\u003c\/h3\u003e\n  \u003c\/div\u003e\n  \u003cdiv class=\"DAV-accordion-A\"\u003e\n    \u003cp\u003eBeing \u003cstrong\u003ewaterproof and argon-purged\u003c\/strong\u003e prevents internal fogging on dewy nights, which can ruin an observing session. It also protects the internal multicoatings from moisture, dust, and fungus, ensuring the eyepiece lasts for many years.\u003c\/p\u003e\n  \u003c\/div\u003e\n  \u003cdiv class=\"DAV-accordion\"\u003e\n    \u003ch3 class=\"DAV-accordion-Q\"\u003eHow would the 72° ED 25mm eyepiece perform on the Pleiades (M45) in an 8-inch Dobsonian?\u003c\/h3\u003e\n  \u003c\/div\u003e\n  \u003cdiv class=\"DAV-accordion-A\"\u003e\n    \u003cp\u003eIt would be an excellent choice. An 8-inch f\/6 Dobsonian has a focal length of about 1200mm, so a 25mm eyepiece yields 48x magnification. This low power combined with the wide 72° field would beautifully frame the entire Pleiades star cluster, showing the main stars as sharp points against a dark background with hints of the surrounding nebulosity.\u003c\/p\u003e\n  \u003c\/div\u003e\n    \u003cdiv class=\"DAV-accordion\"\u003e\n    \u003ch3 class=\"DAV-accordion-Q\"\u003eIs the Explore Scientific 72° 25mm a good \"finder\" eyepiece for an f\/10 Schmidt-Cassegrain Telescope?\u003c\/h3\u003e\n  \u003c\/div\u003e\n  \u003cdiv class=\"DAV-accordion-A\"\u003e\n    \u003cp\u003eAbsolutely. In a typical 8-inch f\/10 SCT with a 2032mm focal length, the 25mm eyepiece provides 81x magnification and the widest possible true field of view. This makes it invaluable for locating faint galaxies and nebulae before switching to higher-power eyepieces for detailed observation.\u003c\/p\u003e\n  \u003c\/div\u003e\n\u003c\/li\u003e\n\n\u003cli\u003e\n  \u003ctable class=\"DAV-specifications\"\u003e\n    \u003ctbody\u003e\n      \n    \u003c\/tbody\u003e\n  \u003c\/table\u003e\n\u003c\/li\u003e\n\n\u003cli\u003e\n  \u003cul class=\"DAV-grid\"\u003e\n    \n  \u003c\/ul\u003e\n\u003c\/li\u003e\n\n\u003cli\u003e\n\u003cul class=\"DAV-grid\"\u003e\n\n\u003c\/ul\u003e\n\u003c\/li\u003e\n\n\u003cli\u003e\n\u003ca href=\"https:\/\/davidastro.com\/pages\/explore-scientific-warranty-policy\" rel=\"noopener\" target=\"_blank\"\u003eExplore Scientific Warranty\u003c\/a\u003e\n\u003c\/li\u003e\n\u003c\/ul\u003e","brand":"Explore Scientific","offers":[{"title":"Default Title","offer_id":52909342949661,"sku":"ES-EPWP7225ED-01","price":349.99,"currency_code":"USD","in_stock":true}],"thumbnail_url":"\/\/cdn.shopify.com\/s\/files\/1\/0753\/5280\/1565\/files\/ExploreScientific-72-ED-Series-25mm-Waterproof-Eyepiece-1_f7cbfb08-bde2-4fe2-a509-5356ee8c0fb2.jpg?v=1789061348","url":"https:\/\/davidastro.com\/en-us\/products\/explore-scientific-epwp7225ed-01","provider":"David Astro","version":"1.0","type":"link"}