{"product_id":"explore-scientific-epwp9225ed-01","title":"Explore Scientific 92° ED Series 25mm Waterproof Eyepiece","description":"\u003cul class=\"DAV-feature-list\"\u003e\n\u003cli\u003e92° Apparent Field of View\u003c\/li\u003e\n\u003cli\u003e25mm Focal Length\u003c\/li\u003e\n\u003cli\u003e2\" Barrel Diameter\u003c\/li\u003e\n\u003cli\u003eExtra-Low Dispersion (ED) Glass\u003c\/li\u003e\n\u003cli\u003eWaterproof and Fog-Proof 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\u003e92° ED Series 25mm Waterproof Eyepiece\u003c\/h2\u003e\n\u003cp\u003eThe Explore Scientific 92° ED Series 25mm Waterproof Eyepiece delivers an ultra-wide, low-magnification viewing experience in a 2-inch barrel format. Its 25mm focal length is designed for sweeping through vast star fields, while the immense 92° apparent field of view creates a genuine \"spacewalk\" immersion that narrower designs cannot replicate.\u003c\/p\u003e\n\u003c\/div\u003e\n\u003c\/div\u003e\n\u003cdiv class=\"DAV-bg-light\"\u003e\n\u003cdiv class=\"DAV-section\"\u003e\n\u003ch3\u003eA 92° Panoramic Window on the Cosmos\u003c\/h3\u003e\n\u003cp\u003eThe 92° apparent field of view fundamentally changes how you observe. Instead of looking through a narrow portal, the view fills your perception, allowing large deep-sky objects to be seen in their entirety. You can frame the full expanse of the Andromeda Galaxy (M31) or trace the intricate dust lanes of the North American Nebula (NGC 7000) without panning your telescope.\u003c\/p\u003e\n\u003cp\u003eThis eyepiece is engineered to serve as a wide-field finder and a primary observing instrument. The low power provided by the 25mm focal length makes it easy to locate targets and appreciate the grand scale of the Milky Way's star clouds.\u003c\/p\u003e\n\u003c\/div\u003e\n\u003c\/div\u003e\n\u003cdiv class=\"DAV-bg-light\"\u003e\n\u003cdiv class=\"DAV-section\"\u003e\n\u003ch3\u003eED Glass for High-Contrast, Color-Free Views\u003c\/h3\u003e\n\u003cp\u003eThis eyepiece uses Extra-Low Dispersion (ED) glass to significantly reduce chromatic aberration—the false color fringing seen around bright stars and planetary limbs. By correcting for this distortion, star points remain sharp and white across the field, and subtle color differences in nebulae become more apparent.\u003c\/p\u003e\n\u003cp\u003eThe primary benefit is a dramatic increase in contrast. With chromatic aberration suppressed, the sky background appears darker and the separation between faint objects and the surrounding space is much more distinct, improving the visibility of faint galactic arms and nebulous filaments.\u003c\/p\u003e\n\u003c\/div\u003e\n\u003c\/div\u003e\n\u003cdiv class=\"DAV-bg-light\"\u003e\n\u003cdiv class=\"DAV-section\"\u003e\n\u003ch3\u003eWaterproof Construction for All-Night Observing\u003c\/h3\u003e\n\u003cp\u003eBuilt to withstand challenging field conditions, this eyepiece is fully waterproof. The internal optical chambers are sealed and purged, preventing internal fogging when moving from a warm house to a cool observing site. This also protects the internal lens surfaces from dust and moisture, ensuring long-term optical integrity.\u003c\/p\u003e\n\u003cp\u003eThe design incorporates long eye relief, providing comfortable viewing for extended periods. This is a critical feature for observers who wear eyeglasses, allowing them to see the entire 92° field without having to press their eye against the lens.\u003c\/p\u003e\n\u003c\/div\u003e\n\u003c\/div\u003e\n\u003cdiv class=\"DAV-bg-light\"\u003e\n\u003cdiv class=\"DAV-section\"\u003e\n\u003ch3\u003e92° vs. 70° Field: The Immersive Difference\u003c\/h3\u003e\n\u003cp\u003eWhile a 70° eyepiece offers a wide view, a 92° field delivers a qualitatively different experience. The key distinction is the role of the field stop—the black edge of the viewing circle.\u003c\/p\u003e\n\u003cul\u003e\n\u003cli\u003e\n\u003cstrong\u003e70° Field:\u003c\/strong\u003e You are aware of the field stop. The view feels like a generous window, but it is still clearly a window.\u003c\/li\u003e\n\u003cli\u003e\n\u003cstrong\u003e92° Field:\u003c\/strong\u003e The field stop recedes into your peripheral vision, often disappearing entirely. This creates the sensation of being suspended in space rather than looking through an instrument, which is the ultimate goal of an ultra-wide eyepiece. The trade-off for this immersion is the requirement for a 2\" focuser, which is not standard on all telescopes.\u003c\/li\u003e\n\u003c\/ul\u003e\n\u003c\/div\u003e\n\u003c\/div\u003e\n\u003c\/div\u003e\n\u003c\/li\u003e\n\u003cli\u003e\n\u003cdiv class=\"DAV-accordion\"\u003e\n\u003ch3 class=\"DAV-accordion-Q\"\u003eWhat makes the Explore Scientific 92° 25mm eyepiece ideal for large deep sky objects?\u003c\/h3\u003e\n\u003c\/div\u003e\n\u003cdiv class=\"DAV-accordion-A\"\u003e\n\u003cp\u003eThe combination of a long \u003cstrong\u003e25mm focal length\u003c\/strong\u003e (for low magnification) and an enormous \u003cstrong\u003e92° apparent field of view\u003c\/strong\u003e allows you to fit exceptionally large objects like the Andromeda Galaxy (M31) or the Veil Nebula complex into a single frame. This contextual view is impossible to achieve with standard eyepieces at the same magnification.\u003c\/p\u003e\n\u003c\/div\u003e\n\u003cdiv class=\"DAV-accordion\"\u003e\n\u003ch3 class=\"DAV-accordion-Q\"\u003eHow will the 92° 25mm eyepiece perform in an 8\" f\/10 SCT on the Orion Nebula (M42)?\u003c\/h3\u003e\n\u003c\/div\u003e\n\u003cdiv class=\"DAV-accordion-A\"\u003e\n\u003cp\u003eIn a typical 8\" f\/10 SCT with a 2032mm focal length, this 25mm eyepiece will yield approximately 81x magnification. The true field of view will be over 1.1°, wide enough to frame not just the core Trapezium stars but also the entire \"wingspan\" of the Orion Nebula (M42) and its neighbor, De Mairan's Nebula (M43), with dark sky around them. The ED glass will ensure the hot, bright stars of the Trapezium are rendered as sharp points without distracting purple halos.\u003c\/p\u003e\n\u003c\/div\u003e\n\u003cdiv class=\"DAV-accordion\"\u003e\n\u003ch3 class=\"DAV-accordion-Q\"\u003eWhat is the main benefit of ED glass in the Explore Scientific 92° 25mm eyepiece?\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. In practical terms, this means you get higher contrast and sharper views. Bright stars will not show false color fringes (like purple halos), and the background sky will appear darker, making it easier to see faint details in galaxies and nebulae.\u003c\/p\u003e\n\u003c\/div\u003e\n\u003cdiv class=\"DAV-accordion\"\u003e\n\u003ch3 class=\"DAV-accordion-Q\"\u003eIs the Explore Scientific 92° 25mm eyepiece a good choice for planetary viewing?\u003c\/h3\u003e\n\u003c\/div\u003e\n\u003cdiv class=\"DAV-accordion-A\"\u003e\n\u003cp\u003eNo, this eyepiece is not designed for high-magnification planetary viewing. Its long 25mm focal length provides low power, which is ideal for deep-sky objects. For observing fine details on Jupiter or the rings of Saturn, a short focal length eyepiece (e.g., 5mm to 9mm) would be a much better choice.\u003c\/p\u003e\n\u003c\/div\u003e\n\u003cdiv class=\"DAV-accordion\"\u003e\n\u003ch3 class=\"DAV-accordion-Q\"\u003eIs the long eye relief of this eyepiece suitable for observers who wear glasses?\u003c\/h3\u003e\n\u003c\/div\u003e\n\u003cdiv class=\"DAV-accordion-A\"\u003e\n\u003cp\u003eYes. The long eye relief is a key feature designed for comfort, especially for eyeglass wearers. It allows you to position your eye at a sufficient distance to see the entire vast 92° field of view without removing your glasses, which is critical if you need them to correct for astigmatism.\u003c\/p\u003e\n\u003c\/div\u003e\n\u003cdiv class=\"DAV-accordion\"\u003e\n\u003ch3 class=\"DAV-accordion-Q\"\u003eWhat does the \"waterproof\" feature mean for the 92° 25mm eyepiece?\u003c\/h3\u003e\n\u003c\/div\u003e\n\u003cdiv class=\"DAV-accordion-A\"\u003e\n\u003cp\u003eBeing waterproof means the eyepiece is internally sealed and purged with an inert gas. This has two major benefits for an observer:\u003c\/p\u003e\n\u003cul\u003e\n\u003cli\u003e\n\u003cstrong\u003ePrevents Internal Fogging:\u003c\/strong\u003e It won't fog up on the inside during nights with heavy dew.\u003c\/li\u003e\n\u003cli\u003e\n\u003cstrong\u003eKeeps Dust Out:\u003c\/strong\u003e The seals prevent dust, pollen, and other contaminants from getting inside the eyepiece and settling on the lens surfaces, ensuring a clean view for years.\u003c\/li\u003e\n\u003c\/ul\u003e\n\u003c\/div\u003e\n\u003c\/li\u003e\n\u003cli\u003e\n\u003ctable class=\"DAV-specifications\"\u003e\n\u003ctbody\u003e\n\u003c\/tbody\u003e\n\u003c\/table\u003e\n\u003c\/li\u003e\n\u003cli\u003e\n\u003cul class=\"DAV-grid\"\u003e\n\u003c\/ul\u003e\n\u003c\/li\u003e\n\u003cli\u003e\n\u003cul class=\"DAV-grid\"\u003e\n\u003c\/ul\u003e\n\u003c\/li\u003e\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":52909354582301,"sku":"ES-EPWP9225ED-01","price":499.99,"currency_code":"USD","in_stock":true}],"thumbnail_url":"\/\/cdn.shopify.com\/s\/files\/1\/0753\/5280\/1565\/files\/ExploreScientific-92-ED-Series-25mm-Waterproof-Eyepiece-1_a286425f-d806-4d32-98c2-c9651fb00c61.jpg?v=1789061413","url":"https:\/\/davidastro.com\/en-us\/products\/explore-scientific-epwp9225ed-01","provider":"David Astro","version":"1.0","type":"link"}