{"product_id":"tele-vue-nagler-t5-31mm-82-eyepiece","title":"Tele Vue Nagler T5 31mm 82° Eyepiece - 2\"","description":"\u003cul class=\"DAV-feature-list\"\u003e\n\u003cli\u003e31mm Focal Length\u003c\/li\u003e\n\u003cli\u003e82° Apparent Field of View\u003c\/li\u003e\n\u003cli\u003e2\" Diameter Barrel\u003c\/li\u003e\n\u003cli\u003e19mm Eye Relief\u003c\/li\u003e\n\u003cli\u003e42mm Field Stop\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\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 Nagler T5 31mm 82° Eyepiece - 2\"\u003c\/h2\u003e\n      \u003cp\u003eThe Type 5 31mm Nagler delivers the maximum possible true field of view in a 2-inch format while maintaining an expansive 82° apparent field. Known affectionately as \"The Terminator,\" this six-element powerhouse is designed to provide a spacewalk perspective that remains sharp across the entire focal plane. It serves as the definitive low-power tool for large-aperture Dobsonians and fast refractors where framing massive celestial structures is the priority.\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\u003eTrue Field and Edge Performance\u003c\/h3\u003e\n      \u003cp\u003eBy utilizing a 42mm field stop, the 31mm Nagler pushes the physical limits of the 2-inch barrel to maximize the amount of sky visible at moderate magnifications. This allows for high-contrast views of expansive targets like the Orion nebula or the Pleiades without sacrificing the magnification needed to resolve fine structural details.\u003c\/p\u003e\n      \u003cul\u003e\n        \u003cli\u003e\n\u003cstrong\u003eNagler Contrast:\u003c\/strong\u003e Full multi-coatings and blackened lens edges eliminate internal reflections, ensuring a dark background sky even near bright lunar or planetary targets.\u003c\/li\u003e\n        \u003cli\u003e\n\u003cstrong\u003eField Correction:\u003c\/strong\u003e The Nagler design effectively minimizes astigmatism and lateral color, keeping star points tight and undistorted from the center to the field stop.\u003c\/li\u003e\n        \u003cli\u003e\n\u003cstrong\u003eEyeglass Compatibility:\u003c\/strong\u003e 19mm of eye relief ensures that most observers can take in the full 82° field without removing their glasses.\u003c\/li\u003e\n      \u003c\/ul\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\u003eHandling and Mechanical Considerations\u003c\/h3\u003e\n      \u003cp\u003eDue to its significant 2.2 lb mass, the 31mm Nagler requires intentional management of telescope balance and focuser tension. The rubberized grip ring ensures secure handling in cold environments or when wearing gloves, providing confidence during eyepiece swaps.\u003c\/p\u003e\n      \u003cul\u003e\n        \u003cli\u003e\n\u003cstrong\u003eFocuser Load:\u003c\/strong\u003e The weight of this eyepiece can cause slip in friction-based focusers; ensure your drawtube tension is adjusted to prevent focal shift.\u003c\/li\u003e\n        \u003cli\u003e\n\u003cstrong\u003eStorage:\u003c\/strong\u003e Given its physical volume, this eyepiece requires a dedicated large-format foam cutout in your accessory case to prevent movement during transport.\u003c\/li\u003e\n        \u003cli\u003e\n\u003cstrong\u003eSafety Taper:\u003c\/strong\u003e The 2\" barrel is machined with a safety undercut to prevent the eyepiece from falling out of the diagonal or focuser should the set screw loosen.\u003c\/li\u003e\n      \u003c\/ul\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\u003eOperational Comparison\u003c\/h3\u003e\n      \u003cp\u003eFlagship eyepieces are defined by the trade-off between apparent field, exit pupil, and physical portability.\u003c\/p\u003e\n      \u003cul\u003e\n        \u003cli\u003e\n\u003cstrong\u003evs. Tele Vue 41mm Panoptic:\u003c\/strong\u003e The 41mm Panoptic offers a slightly larger 46mm field stop, but the 31mm Nagler provides higher magnification and a much more immersive 82° apparent field.\u003c\/li\u003e\n        \u003cli\u003e\n\u003cstrong\u003evs. Tele Vue 31mm Nagler (Type 4):\u003c\/strong\u003e While the Type 5 is the modern standard, the previous Type 4 designs focused on even longer eye relief at the cost of a slightly larger physical footprint.\u003c\/li\u003e\n      \u003c\/ul\u003e\n    \u003c\/div\u003e\n  \u003c\/div\u003e\n\u003c\/div\u003e\n\u003c\/li\u003e\n\n\u003cli\u003e\n  \u003cdiv class=\"DAV-accordion\"\u003e\n    \u003ch3 class=\"DAV-accordion-Q\"\u003eWill the 31mm Nagler work well with an f\/4.5 telescope?\u003c\/h3\u003e\n  \u003c\/div\u003e\n  \u003cdiv class=\"DAV-accordion-A\"\u003e\n    \u003cp\u003eYes, but it produces a 6.9mm exit pupil; if your eye's pupil cannot dilate this wide, you will lose light and may see the secondary mirror shadow in reflectors.\u003c\/p\u003e\n  \u003c\/div\u003e\n  \u003cdiv class=\"DAV-accordion\"\u003e\n    \u003ch3 class=\"DAV-accordion-Q\"\u003eIs a Paracorr necessary for this eyepiece?\u003c\/h3\u003e\n  \u003c\/div\u003e\n  \u003cdiv class=\"DAV-accordion-A\"\u003e\n    \u003cp\u003eIn fast Newtonian systems (f\/5 or faster), the wide field will make mirror coma very obvious at the edges, so a Tele Vue Paracorr is highly recommended to maintain sharpness.\u003c\/p\u003e\n  \u003c\/div\u003e\n  \u003cdiv class=\"DAV-accordion\"\u003e\n    \u003ch3 class=\"DAV-accordion-Q\"\u003eCan I use the 31mm Nagler on a 1.25\" focuser?\u003c\/h3\u003e\n  \u003c\/div\u003e\n  \u003cdiv class=\"DAV-accordion-A\"\u003e\n    \u003cp\u003eNo, this is a dedicated 2\" eyepiece; the 42mm field stop is physically too large to be supported by the 1.25\" format.\u003c\/p\u003e\n  \u003c\/div\u003e\n  \u003cdiv class=\"DAV-accordion\"\u003e\n    \u003ch3 class=\"DAV-accordion-Q\"\u003eHow do I prevent the eyepiece from fogging?\u003c\/h3\u003e\n  \u003c\/div\u003e\n  \u003cdiv class=\"DAV-accordion-A\"\u003e\n    \u003cp\u003eDue to the large mass of glass, it takes longer to reach ambient temperature; using dew heater strips or keeping the eyepiece in a pocket when not in use is recommended.\u003c\/p\u003e\n  \u003c\/div\u003e\n  \u003cdiv class=\"DAV-accordion\"\u003e\n    \u003ch3 class=\"DAV-accordion-Q\"\u003eDoes it include Dioptrx compatibility?\u003c\/h3\u003e\n  \u003c\/div\u003e\n  \u003cdiv class=\"DAV-accordion-A\"\u003e\n    \u003cp\u003eYes, the top of the eyepiece is designed to accept Tele Vue Dioptrx astigmatism correctors, allowing for glasses-free observing.\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      \u003ctr\u003e\n\u003ctd\u003eModel #\u003c\/td\u003e\n\u003ctd\u003eEN5-31.0\u003c\/td\u003e\n\u003c\/tr\u003e\n      \u003ctr\u003e\n\u003ctd\u003eFocal Length\u003c\/td\u003e\n\u003ctd\u003e31 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\u003e82°\u003c\/td\u003e\n\u003c\/tr\u003e\n      \u003ctr\u003e\n\u003ctd\u003eEye Relief\u003c\/td\u003e\n\u003ctd\u003e19 mm\u003c\/td\u003e\n\u003c\/tr\u003e\n      \u003ctr\u003e\n\u003ctd\u003eField Stop Diameter\u003c\/td\u003e\n\u003ctd\u003e42 mm\u003c\/td\u003e\n\u003c\/tr\u003e\n      \u003ctr\u003e\n\u003ctd\u003eWeight\u003c\/td\u003e\n\u003ctd\u003e2.2 lbs (1000 g)\u003c\/td\u003e\n\u003c\/tr\u003e\n      \u003ctr\u003e\n\u003ctd\u003eElements\/Groups\u003c\/td\u003e\n\u003ctd\u003e6 \/ 4\u003c\/td\u003e\n\u003c\/tr\u003e\n    \u003c\/tbody\u003e\n  \u003c\/table\u003e\n\u003c\/li\u003e\n\n\u003cli\u003e\n  \u003cul class=\"DAV-grid\"\u003e\n    \u003cli class=\"DAV-grid-item\"\u003e\n      \u003cimg src=\"https:\/\/cdn.shopify.com\/s\/files\/1\/0753\/5280\/1565\/files\/Tele-Vue-Nagler-31mm-Eyepiece-1.jpg?v=1776474226\" alt=\"Tele Vue 31mm Nagler Eyepiece\" class=\"DAV-img-box\"\u003e\n      \u003cdiv\u003e\n        \u003cp class=\"DAV-item-title\"\u003e31mm Nagler 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 src=\"https:\/\/cdn.shopify.com\/s\/files\/1\/0753\/5280\/1565\/files\/TeleVue-2inch-Dustcap.jpg\" alt=\"2-inch Dust Caps\" class=\"DAV-img-box\"\u003e\n      \u003cdiv\u003e\n        \u003cp class=\"DAV-item-title\"\u003eDust Caps\u003c\/p\u003e\n        \u003cp class=\"DAV-item-subtitle\"\u003e× 2\u003c\/p\u003e\n      \u003c\/div\u003e\n    \u003c\/li\u003e\n  \u003c\/ul\u003e\n\u003c\/li\u003e\n\n\u003cli\u003e\n\u003cul class=\"DAV-grid\"\u003e\n\u003cli class=\"DAV-grid-item\"\u003e\u003ca href=\"https:\/\/www.televue.com\/pdf\/literature\/Nagler%20Type%204%20and%205%20Instructions.pdf\" 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\n\u003cli\u003e\n\u003ca href=\"https:\/\/davidastro.com\/pages\/televue-warranty-policy\" rel=\"noopener\" target=\"_blank\"\u003eTele Vue 5-Year Limited Warranty\u003c\/a\u003e\n\u003c\/li\u003e\n\u003c\/ul\u003e","brand":"TeleVue","offers":[{"title":"Default Title","offer_id":51181118128413,"sku":"TV-EN5-31.0","price":794.18,"currency_code":"USD","in_stock":true}],"thumbnail_url":"\/\/cdn.shopify.com\/s\/files\/1\/0753\/5280\/1565\/files\/Tele-Vue-Nagler-31mm-Eyepiece-1.jpg?v=1776474226","url":"https:\/\/davidastro.com\/en-eu\/products\/tele-vue-nagler-t5-31mm-82-eyepiece","provider":"David Astro","version":"1.0","type":"link"}