{"product_id":"tele-vue-eyepiece-41mm-used","title":"Tele-Vue Panoptic 41mm - Used","description":"\u003cul class=\"DAV-feature-list\"\u003e\n\u003cli\u003eUsed, in Really Good Condition\u003c\/li\u003e\n\u003cli\u003eComes with its Original Boxes and Dust Caps\u003c\/li\u003e\n\u003cli\u003e41mm Focal Length, 68° Apparent Field of View\u003c\/li\u003e\n\u003cli\u003e27mm Eye Relief\u003c\/li\u003e\n\u003cli\u003e46mm Field Stop, the 2\" Maximum\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\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 Panoptic 41mm 68° Eyepiece - 2\" - Used\u003c\/h2\u003e\n\u003cp\u003eThis used Tele Vue Panoptic 41mm 68° Eyepiece is in really good condition and comes with its original boxes. It has a 46mm field stop, the maximum for 2\" eyepieces, with a 68° apparent field, 27mm of eye relief and 6 elements in 4 groups. Its true field is the largest possible in a 2-inch barrel eyepiece, ideal for large nebulae such as the Orion Nebula (M42) and for galaxies.\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 46mm Field Stop: The Maximum True Field in a 2-inch Barrel\u003c\/h3\u003e\n\u003cp\u003eThe fundamental limit on an eyepiece's true field of view (TFoV) is its field stop, the internal metal ring that defines the edge of the view. The Panoptic 41mm has a 46mm field stop, the maximum for 2\" eyepieces; Tele Vue's 55mm Plössl shares it. The true field of both is the largest possible in a 2-inch barrel eyepiece.\u003c\/p\u003e\n\u003cp\u003eYou can calculate the true field for your specific telescope using the formula: TFoV = (Eyepiece Field Stop ÷ Telescope Focal Length) × 57.3. For an SCT with a 2800mm focal length, the Panoptic 41mm yields a true field of (46 ÷ 2800) × 57.3 = 0.94°, nearly two full Moons across, enough for the Lagoon Nebula's (M8) bright core with room around it.\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\u003e9.1mm to 2.9mm Exit Pupils: Performance from f\/4.5 to f\/14\u003c\/h3\u003e\n\u003cp\u003eAn eyepiece's exit pupil determines image brightness and is critical for matching the optic to your telescope and observing conditions. The Panoptic 41mm produces a range of exit pupils suited for various instruments, from a very large 9.1mm on a fast f\/4.5 \u003ca href=\"\/en-us\/collections\/dobsonians\"\u003eDobsonian\u003c\/a\u003e to a more moderate 2.9mm on a slow f\/14 \u003ca href=\"\/en-us\/collections\/maksutov-cassegrain-telescopes\"\u003eMaksutov-Cassegrain\u003c\/a\u003e. Tele Vue's chart gives 9.1, 7.9, 5.9, 4.1 and 2.9mm at f\/4.5, f\/5.2, f\/7, f\/10 and f\/14.\u003c\/p\u003e\n\u003cp\u003eAvoid exit pupils larger than 7mm in reflecting telescopes; \u003ca href=\"\/en-us\/collections\/refractors\"\u003erefractors\u003c\/a\u003e have no upper limit. In an f\/4.5 or f\/5.2 \u003ca href=\"\/en-us\/collections\/reflectors\"\u003ereflector\u003c\/a\u003e the 41mm exceeds that 7mm, so a shorter eyepiece suits those telescopes better. The eyeguard also helps minimize \"pupil shadowing\".\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\u003e27mm Eye Relief for Eyeglass and Dioptrx Use\u003c\/h3\u003e\n\u003cp\u003eWith 27mm of eye relief, more than the 15mm to 20mm suggested for eyeglass wearers, the Panoptic 41mm suits observers who wear glasses. Eyeglass wearers can completely unscrew and remove the eyeguard housing for maximum eye relief. The Adjustable Height Eyeguard Adapter positions your eye in the exit pupil and reduces stray light; its soft rubber eyeguard can be used extended, rolled back or removed.\u003c\/p\u003e\n\u003cp\u003eThe 41mm accepts Tele Vue's Dioptrx, which locks onto the top of the eyepiece and replaces glasses for astigmatism. Astigmatism is likely to be visible with long focal length eyepieces that produce large exit pupils. Dioptrx comes in ¼ to 3½ diopter.\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\u003ePanoptic 41mm vs. Plössl 55mm and Nagler 31mm\u003c\/h3\u003e\n\u003cul\u003e\n\u003cli\u003e\n\u003cstrong\u003evs. Tele Vue 55mm Plössl:\u003c\/strong\u003e Both have a 46.0mm field stop and show the same true field. The 55mm gives lower power and a larger exit pupil, useful in slow telescopes, with 38mm of eye relief. The 41mm gives more magnification across a 68° field; for a given field stop, the shorter focal length and wider apparent field show more detail and fainter stars.\u003c\/li\u003e\n\u003cli\u003e\n\u003cstrong\u003evs. Tele Vue 31mm Nagler:\u003c\/strong\u003e The 31mm Nagler has an 82° apparent field and a 42.0mm field stop, so it shows slightly less sky, with 19mm of eye relief. The Panoptic has 27mm of eye relief and weighs 33.6 oz against the Nagler's 2.2 lbs.\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\u003eHandling and Care\u003c\/h3\u003e\n\u003cp\u003eThe Tele Vue Panoptic 41mm weighs 33.6 oz (2.10 lb) and has 6 elements in 4 groups, with multi-coatings and blackened lens edges. Do not unscrew the chrome barrel, or the lenses will fall out.\u003c\/p\u003e\n\u003cp\u003eClean the eyelens only when necessary. Unscrew the eyeguard housing completely for access. Use a bulb-type puffer to blow off loose dust, then clean the surface with a gently moistened (not soaked) Q-Tip in a circular motion. Never pour liquid directly on the lens: capillary action can carry it into the eyepiece and dissolve the lens edge blackening.\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 Note on Used Condition\u003c\/h3\u003e\n\u003cp\u003eThis Tele Vue Panoptic 41mm is a used eyepiece in really good condition. It comes with its two dust caps and its original Tele Vue boxes, and offers the same views as a new one at a lower price. This used eyepiece is sold without warranty.\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\"\u003eDoes the Tele Vue Panoptic 41mm show more sky than the 55mm Plössl?\u003c\/h3\u003e\n\u003c\/div\u003e\n\u003cdiv class=\"DAV-accordion-A\"\u003e\n\u003cp\u003eNo. Both have a 46mm field stop, the 2\" maximum. Because they share the same field stop diameter, they show the exact same true field of view in a given telescope. The Panoptic provides higher magnification and a wider apparent field within that true field.\u003c\/p\u003e\n\u003c\/div\u003e\n\u003cdiv class=\"DAV-accordion\"\u003e\n\u003ch3 class=\"DAV-accordion-Q\"\u003eCan I use the Tele Vue Panoptic 41mm in my fast f\/4.5 Newtonian?\u003c\/h3\u003e\n\u003c\/div\u003e\n\u003cdiv class=\"DAV-accordion-A\"\u003e\n\u003cp\u003eIt is a poor match. In an f\/4.5 telescope it gives a 9.1mm exit pupil, beyond the 7mm limit for reflectors, so you lose light and may see the secondary mirror's shadow.\u003c\/p\u003e\n\u003c\/div\u003e\n\u003cdiv class=\"DAV-accordion\"\u003e\n\u003ch3 class=\"DAV-accordion-Q\"\u003eIs the 27mm eye relief on the Panoptic 41mm good for eyeglass wearers?\u003c\/h3\u003e\n\u003c\/div\u003e\n\u003cdiv class=\"DAV-accordion-A\"\u003e\n\u003cp\u003eYes. 27mm is more than the 15mm to 20mm suggested for eyeglass wearers, and you can completely unscrew and remove the eyeguard housing for maximum eye relief.\u003c\/p\u003e\n\u003c\/div\u003e\n\u003cdiv class=\"DAV-accordion\"\u003e\n\u003ch3 class=\"DAV-accordion-Q\"\u003eHow do I frame the Andromeda Galaxy (M31) with the Panoptic 41mm?\u003c\/h3\u003e\n\u003c\/div\u003e\n\u003cdiv class=\"DAV-accordion-A\"\u003e\n\u003cp\u003eIn a telescope with a focal length around 1200mm (like an 8\" f\/6 Dobsonian), this eyepiece provides a true field of approximately 2.2°. That holds much of M31's length with M32 and M110 in the same field.\u003c\/p\u003e\n\u003c\/div\u003e\n\u003cdiv class=\"DAV-accordion\"\u003e\n\u003ch3 class=\"DAV-accordion-Q\"\u003eIs the Tele Vue Panoptic 41mm compatible with Dioptrx?\u003c\/h3\u003e\n\u003c\/div\u003e\n\u003cdiv class=\"DAV-accordion-A\"\u003e\n\u003cp\u003eYes. Astigmatism is likely to show with large exit pupils, such as this eyepiece gives.\u003c\/p\u003e\n\u003c\/div\u003e\n\u003cdiv class=\"DAV-accordion\"\u003e\n\u003ch3 class=\"DAV-accordion-Q\"\u003eIs the 33.6 oz weight of the Panoptic 41mm a problem for balancing?\u003c\/h3\u003e\n\u003c\/div\u003e\n\u003cdiv class=\"DAV-accordion-A\"\u003e\n\u003cp\u003eAt 2.10 lbs it can shift a telescope's balance; rebalance when you switch to it.\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\u003eSKU\u003c\/td\u003e\n\u003ctd\u003eU-DAV-TV-EPN-41.0\u003c\/td\u003e\n\u003c\/tr\u003e\n\u003ctr\u003e\n\u003ctd\u003eModel #\u003c\/td\u003e\n\u003ctd\u003eEPN-41.0\u003c\/td\u003e\n\u003c\/tr\u003e\n\u003ctr\u003e\n\u003ctd\u003eCondition\u003c\/td\u003e\n\u003ctd\u003eUsed, really good condition\u003c\/td\u003e\n\u003c\/tr\u003e\n\u003ctr\u003e\n\u003ctd\u003eWarranty\u003c\/td\u003e\n\u003ctd\u003eNone (sold as is)\u003c\/td\u003e\n\u003c\/tr\u003e\n\u003ctr\u003e\n\u003ctd\u003eFocal Length\u003c\/td\u003e\n\u003ctd\u003e41 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\u003e68°\u003c\/td\u003e\n\u003c\/tr\u003e\n\u003ctr\u003e\n\u003ctd\u003eEye Relief\u003c\/td\u003e\n\u003ctd\u003e27 mm\u003c\/td\u003e\n\u003c\/tr\u003e\n\u003ctr\u003e\n\u003ctd\u003eField Stop Diameter\u003c\/td\u003e\n\u003ctd\u003e46 mm\u003c\/td\u003e\n\u003c\/tr\u003e\n\u003ctr\u003e\n\u003ctd\u003eWeight\u003c\/td\u003e\n\u003ctd\u003e33.6 oz (2.10 lb)\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\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\/20261104_155832-62ece33d-8f0c-4786-a95b-1c33ee35330a.jpg?v=1793829286\" alt=\"Tele Vue Panoptic 41mm Eyepiece - Used\" class=\"DAV-img-box\"\u003e\n\u003cdiv\u003e\n\u003cp class=\"DAV-item-title\"\u003eUsed 41mm Panoptic 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=\"Tele Vue 2-inch Dust Cap\" 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\u003cli class=\"DAV-grid-item\"\u003e\n\u003cdiv\u003e\n\u003cp class=\"DAV-item-title\"\u003eOriginal Tele Vue Boxes\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\/Tele-Vue-41mm-Panoptic-Eyepiece-Manual.pdf?v=1776305956\" 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\u003c\/ul\u003e","brand":"TeleVue","offers":[{"title":"Default Title","offer_id":67974899958045,"sku":"U-DAV-TV-EPN-41.0","price":428.0,"currency_code":"USD","in_stock":true}],"thumbnail_url":"\/\/cdn.shopify.com\/s\/files\/1\/0753\/5280\/1565\/files\/20261104_155832-62ece33d-8f0c-4786-a95b-1c33ee35330a.jpg?v=1793829286","url":"https:\/\/davidastro.com\/en-us\/products\/tele-vue-eyepiece-41mm-used","provider":"David Astro","version":"1.0","type":"link"}