{"product_id":"televue-ethos-17mm-100-eyepiece","title":"TeleVue Ethos 17mm 100° Eyepiece - 2\"","description":"\u003cul class=\"DAV-feature-list\"\u003e\n\u003cli\u003e17mm Focal Length\u003c\/li\u003e\n\u003cli\u003eUltra-Wide 100° Apparent Field of View\u003c\/li\u003e\n\u003cli\u003e2\" Diameter Barrel\u003c\/li\u003e\n\u003cli\u003e15mm Eye Relief\u003c\/li\u003e\n\u003cli\u003e29.6mm Field Stop\u003c\/li\u003e\n\u003c\/ul\u003e\n\n\u003c!-- more --\u003e\n\u003cul class=\"tabs\"\u003e\n\u003cli class=\"active\"\u003eDescription\u003c\/li\u003e\n  \u003cli\u003eQ\u0026amp;A\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\u003eTele Vue Ethos 17mm 100° Eyepiece - 2\"\u003c\/h2\u003e\n\u003cp\u003eThe Tele Vue Ethos 17mm eyepiece is a crowning achievement in modern optical engineering, offering a focal length many veteran observers consider the absolute sweet spot for deep sky exploration. While the Ethos series changed the landscape of amateur astronomy with its 100° apparent field of view (AFOV), the 17mm model specifically bridges the gap between low power scanning and high power planetary detail. It provides a massive true field of view while maintaining the magnification necessary to resolve the intricate structures of distant galaxies and nebulae.\u003c\/p\u003e\n\u003cp\u003eStepping up to the Ethos 17mm is less about looking through a telescope and more about looking through a window. The framing is so vast that the metal housing of the eyepiece seems to vanish, leaving you suspended in a panoramic view of the cosmos. For the serious astronomer, this eyepiece represents a lifetime investment in visual excellence, combining the legendary \"spacewalk\" immersion with the uncompromising contrast and sharpness that Al Nagler and his team are known for.\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\u003eThe 100° Experience: Beyond Human Peripheral Vision\u003c\/h3\u003e\n\u003cp\u003eThe primary draw of the Ethos 17mm is its breathtaking 100° apparent field of view. To appreciate the scale, consider that an 82° Nagler, once the gold standard for wide fields, offers significantly less viewing area. The Ethos 17mm provides a field that essentially matches or exceeds the limit of what the human eye can perceive at once, requiring you to move your eye to \"look around\" the scene.\u003c\/p\u003e\n\u003cp\u003eIn practical application, this massive field translates to efficiency. Because the 17mm focal length provides higher magnification than its 21mm sibling, it darkens the sky background significantly, yet the 100° field ensures you are still seeing a swath of sky typically reserved for low power eyepieces. You can frame the entire Double Cluster in Perseus or the expansive tendrils of the Veil Nebula while enjoying the resolution and contrast that come with a 17mm focal length. It effectively does the work of two eyepieces, functioning as both a wide field finder and a high contrast medium power powerhouse.\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\u003ePrecision Optics and Edge-to-Edge Correction\u003c\/h3\u003e\n\u003cp\u003eTele Vue has built its reputation on the ability to handle \"fast\" telescopes. The Ethos 17mm is engineered to perform flawlessly even in f\/4 or f\/4.5 focal ratios, where lesser eyepieces often suffer from astigmatism or field curvature at the edges. This eyepiece maintains pinpoint star images across the entire 29.6mm field stop.\u003c\/p\u003e\n\u003cul\u003e\n\u003cli\u003e\n\u003cstrong\u003eAdvanced Multi-Coatings:\u003c\/strong\u003e Every air-to-glass surface is treated with specialized multi-coatings to ensure maximum light transmission. This results in an exceptionally bright image, allowing you to catch the faintest hints of nebulosity in objects like the Horsehead Nebula.\u003c\/li\u003e\n\u003cli\u003e\n\u003cstrong\u003eSuperior Contrast:\u003c\/strong\u003e The internal mechanical design utilizes extensive baffling and blackened lens edges to eliminate stray light. When a bright star is just outside the field of view, the background remains inky black, free from the \"ghosting\" or glare that plagues many ultra-wide designs.\u003c\/li\u003e\n\u003cli\u003e\n\u003cstrong\u003eOptical Geometry:\u003c\/strong\u003e The Ethos design specifically addresses angular magnification distortion. This means objects retain their correct proportions as they drift from the center to the edge, a critical feature for those using non-tracking Dobsonian telescopes.\u003c\/li\u003e\n\u003cli\u003e\n\u003cstrong\u003eNeutral Color Balance:\u003c\/strong\u003e Tele Vue optics are celebrated for their \"pure\" white light transmission. There is no yellow or blue tinting, ensuring that the natural colors of star clusters and the subtle hues of planetary discs are preserved exactly as they are.\u003c\/li\u003e\n\u003c\/ul\u003e\n\u003c\/div\u003e\n\u003c\/div\u003e\n\u003cdiv class=\"DAV-bg-light\"\u003e\n\u003cdiv class=\"DAV-section\"\u003e\n\u003ch3\u003eOptimizing the Exit Pupil for Deep Sky\u003c\/h3\u003e\n\u003cp\u003eFor many observers, the 17mm focal length is the \"Goldilocks\" zone. In a standard f\/10 Schmidt-Cassegrain, it yields a 1.7mm exit pupil, which is ideal for resolving globular clusters and planetary nebulae. In a fast f\/4.5 Dobsonian, it produces a 3.8mm exit pupil, which is the perfect balance for deep sky work, providing enough light for the eye to perceive color and detail without the sky background becoming washed out by light pollution.\u003c\/p\u003e\n\u003cp\u003eThis versatility makes the Ethos 17mm the most used eyepiece in many collections. Whether you are hunting for small, faint galaxies or taking in the grandeur of the Pleiades, the 17mm provides the scale and brightness required for a truly transformative observing session.\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\u003eErgonomics and Mechanical Excellence\u003c\/h3\u003e\n\u003cp\u003eDespite its complex 100° optical design, the Ethos 17mm remains more manageable than the massive 21mm version. Weighing in at approximately 1.5 lbs (703 g), it is easier to balance on a wider variety of telescope mounts while still feeling like a robust, professional-grade instrument.\u003c\/p\u003e\n\u003cul\u003e\n\u003cli\u003e\n\u003cstrong\u003eSafety and Stability:\u003c\/strong\u003e The 2-inch barrel includes the signature Tele Vue tapered safety undercut. This design ensures that even if your focuser lock loosens slightly, the eyepiece remains securely held, preventing accidental drops.\u003c\/li\u003e\n\u003cli\u003e\n\u003cstrong\u003eViewing Comfort:\u003c\/strong\u003e The 15mm of eye relief is generous for an ultra-wide eyepiece. For those who observe with glasses, the Ethos 17mm is fully compatible with the Tele Vue Dioptrx system, which corrects for eyesight astigmatism so you can observe without the hindrance of spectacles.\u003c\/li\u003e\n\u003cli\u003e\n\u003cstrong\u003eAll-Weather Grip:\u003c\/strong\u003e The textured rubber housing provides a secure grip in humid conditions or when wearing gloves during winter observing sessions. The fold-down rubber eyeguard helps block lateral light pollution and positions the eye at the perfect distance for a comfortable view.\u003c\/li\u003e\n\u003c\/ul\u003e\n\u003c\/div\u003e\n\u003c\/div\u003e\n\u003cdiv class=\"DAV-bg-light\"\u003e\n\u003cdiv class=\"DAV-section\"\u003e\n\u003ch3\u003eComparative Perspective: The 17mm Ethos in the Kit\u003c\/h3\u003e\n\u003cp\u003eHow does the 17mm Ethos compare to other legendary glass in the Tele Vue stable?\u003c\/p\u003e\n\u003cul\u003e\n\u003cli\u003e\n\u003cstrong\u003evs. Ethos 21mm:\u003c\/strong\u003e The 21mm is the \"finder\" of the series with a wider true field. However, the 17mm is often preferred for smaller deep sky objects because the higher magnification makes them easier to see. The 17mm is also significantly lighter and easier to balance.\u003c\/li\u003e\n\u003cli\u003e\n\u003cstrong\u003evs. Nagler 17mm Type 4:\u003c\/strong\u003e The Nagler 17mm is a classic with a very comfortable 82° field. However, the Ethos 17mm provides a nearly 50% larger viewing area and improved edge correction, making it the definitive upgrade for those seeking the ultimate immersion.\u003c\/li\u003e\n\u003cli\u003e\n\u003cstrong\u003evs. Delos 17.3mm:\u003c\/strong\u003e If you require 20mm of eye relief for thick glasses, the Delos is a fantastic choice. But if you want the \"floating in space\" feeling that only a 100° field can provide, the Ethos is unrivaled.\u003c\/li\u003e\n\u003c\/ul\u003e\n\u003c\/div\u003e\n\u003c\/div\u003e\n\u003cdiv class=\"DAV-bg-light\"\u003e\n\u003cdiv class=\"DAV-section\"\u003e\n\u003ch3\u003eIs the Tele Vue Ethos 17mm Right for You?\u003c\/h3\u003e\n\u003cp\u003eThe Ethos 17mm is designed for the observer who refuses to compromise. It is for the astronomer who wants to see the spiral arms of M51 framed by the deep black of space, without the distraction of a narrow field stop. It is a \"forever\" eyepiece, designed to be passed down through generations. When you consider that it can replace several lower-quality eyepieces in your kit, the value becomes clear. You are paying for the highest level of craftsmanship available in the world of consumer optics today.\u003c\/p\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\"\u003eIs the Ethos 17mm compatible with 1.25\" focusers?\u003c\/h3\u003e\n\u003c\/div\u003e\n\u003cdiv class=\"DAV-accordion-A\"\u003e\n\u003cp\u003eNo, due to the large field stop and optical design, this eyepiece requires a 2-inch focuser or diagonal. Attempting to adapt it to 1.25\" would result in severe vignetting.\u003c\/p\u003e\n\u003c\/div\u003e\n\n\u003cdiv class=\"DAV-accordion\"\u003e\n\u003ch3 class=\"DAV-accordion-Q\"\u003eHow does it perform with a Barlow or PowerMate?\u003c\/h3\u003e\n\u003c\/div\u003e\n\u003cdiv class=\"DAV-accordion-A\"\u003e\n\u003cp\u003eExtremely well. Pairing the 17mm Ethos with a 2x PowerMate creates a high-power 8.5mm 100° eyepiece, which is exceptional for high-magnification lunar and planetary viewing while maintaining the immersive wide field.\u003c\/p\u003e\n\u003c\/div\u003e\n\n\u003cdiv class=\"DAV-accordion\"\u003e\n\u003ch3 class=\"DAV-accordion-Q\"\u003eDo I need a Coma Corrector?\u003c\/h3\u003e\n\u003c\/div\u003e\n\u003cdiv class=\"DAV-accordion-A\"\u003e\n\u003cp\u003eIf you are using a Newtonian reflector faster than f\/5, a Tele Vue Paracorr Type 2 is highly recommended. The Ethos 17mm is sharp enough to reveal the inherent coma of your telescope mirror, and the Paracorr will ensure the stars stay sharp to the very edge of that 100° field.\u003c\/p\u003e\n\u003c\/div\u003e\n\n\u003cdiv class=\"DAV-accordion\"\u003e\n\u003ch3 class=\"DAV-accordion-Q\"\u003eIs this eyepiece parfocal?\u003c\/h3\u003e\n\u003c\/div\u003e\n\u003cdiv class=\"DAV-accordion-A\"\u003e\n\u003cp\u003eThe Ethos 17mm is parfocal with the 21mm Ethos, 13mm Ethos, and 31mm Nagler. This allows you to swap between these focal lengths during an observing session with minimal refocusing required.\u003c\/p\u003e\n\u003c\/div\u003e\n\u003c\/li\u003e  \n\u003cli\u003e\n\u003ctable class=\"DAV-specifications\"\u003e\n\u003ctbody\u003e\n\u003ctr\u003e\n\u003ctd\u003eModel #\u003c\/td\u003e\n\u003ctd\u003eETH-17.0\u003c\/td\u003e\n\u003c\/tr\u003e\n\u003ctr\u003e\n\u003ctd\u003eFocal Length\u003c\/td\u003e\n\u003ctd\u003e17 mm\u003c\/td\u003e\n\u003c\/tr\u003e\n\u003ctr\u003e\n\u003ctd\u003eBarrel Size\u003c\/td\u003e\n\u003ctd\u003e2\"\u003c\/td\u003e\n\u003c\/tr\u003e\n\u003ctr\u003e\n\u003ctd\u003eApparent Field of View\u003c\/td\u003e\n\u003ctd\u003e100°\u003c\/td\u003e\n\u003c\/tr\u003e\n\u003ctr\u003e\n\u003ctd\u003eEye Relief\u003c\/td\u003e\n\u003ctd\u003e15 mm\u003c\/td\u003e\n\u003c\/tr\u003e\n\u003ctr\u003e\n\u003ctd\u003eField Stop Diameter\u003c\/td\u003e\n\u003ctd\u003e29.6 mm\u003c\/td\u003e\n\u003c\/tr\u003e\n\u003ctr\u003e\n\u003ctd\u003eWeight\u003c\/td\u003e\n\u003ctd\u003e24.8 oz (1.55 lb \/ 703 g)\u003c\/td\u003e\n\u003c\/tr\u003e\n\u003ctr\u003e\n\u003ctd\u003eOptical Length\u003c\/td\u003e\n\u003ctd\u003e4.4\" (112 mm)\u003c\/td\u003e\n\u003c\/tr\u003e\n\u003c\/tbody\u003e\n\u003c\/table\u003e\n\u003c\/li\u003e\n\u003cli\u003e\n\u003cul class=\"DAV-grid\"\u003e\n\u003cli class=\"DAV-grid-item\"\u003e\n\u003cimg class=\"DAV-img-box\" alt=\"Tele Vue Ethos 17mm Eyepiece\" src=\"https:\/\/cdn.shopify.com\/s\/files\/1\/0753\/5280\/1565\/files\/TeleVue-Ethos-17mm-Eyepiece-1.jpg?v=1774383600\"\u003e\n\u003cdiv\u003e\n\u003cp class=\"DAV-item-title\"\u003eEthos 17mm Eyepiece\u003c\/p\u003e\n\u003cp class=\"DAV-item-subtitle\"\u003e× 1\u003c\/p\u003e\n\u003c\/div\u003e\n\u003c\/li\u003e\n\u003cli class=\"DAV-grid-item\"\u003e\n\u003cimg class=\"DAV-img-box\" alt=\"Tele Vue 2-inch Dust Cap (top)\" src=\"https:\/\/cdn.shopify.com\/s\/files\/1\/0753\/5280\/1565\/files\/TeleVue-2inch-Dustcap.jpg?v=1774403118\"\u003e\n\u003cdiv\u003e\n\u003cp class=\"DAV-item-title\"\u003eDust Cap (Top)\u003c\/p\u003e\n\u003cp class=\"DAV-item-subtitle\"\u003e× 1\u003c\/p\u003e\n\u003c\/div\u003e\n\u003c\/li\u003e\n\u003cli class=\"DAV-grid-item\"\u003e\n\u003cimg class=\"DAV-img-box\" alt=\"Tele Vue 2-inch Dust Cap (bottom)\" src=\"https:\/\/cdn.shopify.com\/s\/files\/1\/0753\/5280\/1565\/files\/TeleVue-2inch-Dustcap.jpg?v=1774403118\"\u003e\n\u003cdiv\u003e\n\u003cp class=\"DAV-item-title\"\u003eDust Cap (Bottom)\u003c\/p\u003e\n\u003cp class=\"DAV-item-subtitle\"\u003e× 1\u003c\/p\u003e\n\u003c\/div\u003e\n\u003c\/li\u003e\n\u003c\/ul\u003e\n\u003c\/li\u003e\n\u003cli\u003e\n\u003cul class=\"DAV-grid\"\u003e\n\u003cli class=\"DAV-grid-item\"\u003e\u003ca href=\"https:\/\/cdn.shopify.com\/s\/files\/1\/0753\/5280\/1565\/files\/TeleVue-Ethos-Eyepiece-Instructions.pdf?v=1774384900\" target=\"_blank\"\u003e\u003csvg class=\"DAV-img-box\" viewbox=\"0 0 512 512\" xmlns=\"http:\/\/www.w3.org\/2000\/svg\"\u003e\u003cpath d=\"M0 64C0 28.7 28.7 0 64 0L224 0l0 128c0 17.7 14.3 32 32 32l128 0 0 144-208 0c-35.3 0-64 28.7-64 64l0 144-48 0c-35.3 0-64-28.7-64-64L0 64zm384 64l-128 0L256 0 384 128zM176 352l32 0c30.9 0 56 25.1 56 56s-25.1 56-56 56l-16 0 0 32c0 8.8-7.2 16-16 16s-16-7.2-16-16l0-48 0-80c0-8.8 7.2-16 16-16zm32 80c13.3 0 24-10.7 24-24s-10.7-24-24-24l-16 0 0 48 16 0zm96-80l32 0c26.5 0 48 21.5 48 48l0 64c0 26.5-21.5 48-48 48l-32 0c-8.8 0-16-7.2-16-16l0-128c0-8.8 7.2-16 16-16zm32 128c8.8 0 16-7.2 16-16l0-64c0-8.8-7.2-16-16-16l-16 0 0 96 16 0zm80-112c0-8.8 7.2-16 16-16l48 0c8.8 0 16 7.2 16 16s-7.2 16-16 16l-32 0 0 32 32 0c8.8 0 16 7.2 16 16s-7.2 16-16 16l-32 0 0 48c0 8.8-7.2 16-16 16s-16-7.2-16-16l0-64 0-64z\" fill=\"#0047a7\"\u003e\u003c\/path\u003e\u003c\/svg\u003e\n\u003cdiv\u003e\n\u003cp class=\"DAV-item-title\"\u003eDownload Manual\u003c\/p\u003e\n\u003c\/div\u003e\n\u003c\/a\u003e\u003c\/li\u003e\n\u003c\/ul\u003e\n\u003c\/li\u003e\n\u003cli\u003e\u003ca href=\"https:\/\/davidastro.com\/pages\/televue-warranty-policy\" target=\"_blank\" rel=\"noopener\"\u003eTeleVue 5-Year Limited Warranty for Telescopes and Accessories\u003c\/a\u003e\u003c\/li\u003e\n\u003c\/ul\u003e","brand":"TeleVue","offers":[{"title":"Default Title","offer_id":51080422392093,"sku":"TV-ETH-17.0","price":901.0,"currency_code":"USD","in_stock":true}],"thumbnail_url":"\/\/cdn.shopify.com\/s\/files\/1\/0753\/5280\/1565\/files\/TeleVue-Ethos-17mm-Eyepiece-1.jpg?v=1774404190","url":"https:\/\/davidastro.com\/fr-int\/products\/televue-ethos-17mm-100-eyepiece","provider":"David Astro","version":"1.0","type":"link"}