{"product_id":"tele-vue-delos-3-5mm-72-degree-eyepiece","title":"Tele Vue Delos 3.5mm 72° Eyepiece - 1.25\"","description":"\u003cul class=\"DAV-feature-list\"\u003e\n\u003cli\u003eFocal Length: 3.5mm\u003c\/li\u003e\n\u003cli\u003eApparent Field of View: 72°\u003c\/li\u003e\n\u003cli\u003eBarrel Size: 1.25\"\u003c\/li\u003e\n\u003cli\u003eEye Relief: 20mm\u003c\/li\u003e\n\u003cli\u003eParfocal: Yes, with most Tele Vue 1.25\" eyepieces\u003c\/li\u003e\n\u003cli\u003eFilter Threads: 1.25\" Standard\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\u003eHigh-Power Views Without Compromise: The Delos 3.5mm Eyepiece\u003c\/h2\u003e\n\u003cp\u003eThe Tele Vue Delos 3.5mm 72° Eyepiece is an optical instrument designed for high-magnification planetary, lunar, and double-star observation, delivering a wide field of view without sacrificing contrast, sharpness, or viewing comfort. It combines a generous 72° apparent field with long eye relief, creating an immersive experience that feels natural and unconstrained, even at extreme magnifications. For the observer who refuses to choose between a wide, engaging view and pure, high-fidelity planetary detail, the Delos 3.5mm is a definitive solution.\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 72° Apparent Field of View\u003c\/h3\u003e\n\u003cp\u003eThe Delos optical design achieves a 72° apparent field of view, creating a viewing window that feels expansive and immersive. This wide field provides a significant advantage at high power, allowing you to track a planet across the field for longer periods on a non-driven or manually guided mount. The optical correction is maintained to the very edge of the field, ensuring stars remain sharp points and planetary limbs are free of distracting distortion or color fringing, a key performance trait for a high-power eyepiece.\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\u003eHigh-Contrast Optical System\u003c\/h3\u003e\n\u003cp\u003eTele Vue utilizes high-index glass elements and applies full multi-coatings to every air-to-glass surface in the Delos 3.5mm. This meticulous approach minimizes scattered light and maximizes throughput, which is critical for discerning low-contrast details at high magnification. The practical result is a darker background sky, which makes subtle features like Jupiter's faint festoons, the delicate crepe ring of Saturn, or minute tonal variations in Martian albedo features more readily visible. The blackened lens edges further enhance this effect by absorbing stray light that would otherwise reduce image contrast.\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 Locking Eyeguard and Consistent Eye Relief\u003c\/h3\u003e\n\u003cp\u003eA core feature of the Delos line is its adjustable, locking eyeguard, paired with a constant 20mm of eye relief across all focal lengths. This system allows you to set the perfect distance between your eye and the top lens, then lock it in place. This provides a stable, repeatable viewing position night after night, eliminating distracting \"blackouts\" or kidney-beaning effects. For observers who wear glasses to correct for astigmatism, the long eye relief ensures you can see the entire 72° field of view comfortably without removing them.\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\u003eParfocal Design for Seamless Transitions\u003c\/h3\u003e\n\u003cp\u003eThe Delos 3.5mm is designed to be nearly parfocal with other Tele Vue 1.25\" eyepieces, including other Delos, Plössls, and Panoptics. This means that when you switch from a lower-power Tele Vue eyepiece to the 3.5mm Delos for a closer look, you will need to make only a minimal adjustment to the focuser. This workflow benefit keeps your target centered and saves valuable time, especially when observing conditions are changing or you are trying to catch a moment of perfect seeing.\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 High-Magnification Experience\u003c\/h3\u003e\n\u003cp\u003eIn a quality 4-inch apochromatic refractor under steady skies, the 3.5mm Delos delivers magnifications in the 200-250x range, ideal for planetary observation. As your eye settles on Jupiter, the view is not just a magnified disk but a detailed globe. You can trace the fine, thread-like structures within the main equatorial belts and watch for transit events of the Galilean moons, whose tiny disks are cleanly resolved against the planet's clouds. The generous field means the planet drifts slowly through the view, allowing you to study features without constant nudging of the telescope.\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 Atmospheric Seeing\u003c\/h3\u003e\n\u003cp\u003eThe primary limitation of any high-power eyepiece is the Earth's atmosphere. At the magnification levels the 3.5mm Delos provides, excellent atmospheric \"seeing\" is required to realize its full potential. On nights of poor seeing, the image will appear soft or shimmering, a condition no eyepiece can correct. Therefore, this is a special-purpose eyepiece you reach for when the air is steady and you want to push your telescope to its resolution limit on the brightest targets.\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\u003eChoosing Your High-Power Tele Vue Eyepiece\u003c\/h3\u003e\n\u003cp\u003eTele Vue offers several eyepiece lines that deliver high magnification. The choice depends on the observer's priorities.\u003c\/p\u003e\n\u003cul\u003e\n\u003cli\u003e\n\u003cstrong\u003eDelos 3.5mm vs. Nagler Type 6 3.5mm:\u003c\/strong\u003e The Nagler offers a wider 82° apparent field, creating a more dramatic \"spacewalk\" effect. However, the Delos provides significantly more eye relief (20mm vs. 12mm), making it the superior choice for eyeglass wearers and many observers who find the longer eye relief more comfortable for extended planetary study.\u003c\/li\u003e\n\u003cli\u003e\n\u003cstrong\u003eDelos 3.5mm vs. DeLite 3mm\/4mm:\u003c\/strong\u003e The DeLite series is smaller, lighter, and more affordable, with a 62° apparent field. The Delos is the choice for observers who want the most immersive high-power view possible while retaining long eye relief. The DeLite is for those who prioritize portability and lower cost while still demanding excellent optical quality and comfort.\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\"\u003eIs the Delos 3.5mm good for observers who wear glasses?\u003c\/h3\u003e\n\u003c\/div\u003e\n\u003cdiv class=\"DAV-accordion-A\"\u003e\n\u003cp\u003eYes. With 20mm of eye relief, the Delos 3.5mm allows most eyeglass wearers to see the full 72° field of view. The adjustable eyeguard helps you find the perfect distance for comfortable viewing with or without glasses.\u003c\/p\u003e\n\u003c\/div\u003e\n\u003cdiv class=\"DAV-accordion\"\u003e\n\u003ch3 class=\"DAV-accordion-Q\"\u003eWhat telescope is best suited for the 3.5mm Delos?\u003c\/h3\u003e\n\u003c\/div\u003e\n\u003cdiv class=\"DAV-accordion-A\"\u003e\n\u003cp\u003eThis eyepiece is ideal for telescopes with focal lengths of 700mm or longer, such as apochromatic refractors, Schmidt-Cassegrains, and Maksutov-Cassegrains. It requires excellent atmospheric conditions to perform at its best due to the high magnification it provides.\u003c\/p\u003e\n\u003c\/div\u003e\n\u003cdiv class=\"DAV-accordion\"\u003e\n\u003ch3 class=\"DAV-accordion-Q\"\u003eHow does the Delos 3.5mm compare to a Nagler 3.5mm?\u003c\/h3\u003e\n\u003c\/div\u003e\n\u003cdiv class=\"DAV-accordion-A\"\u003e\n\u003cp\u003eThe Nagler has a wider 82° field, while the Delos has a 72° field but offers much longer and more comfortable eye relief (20mm vs 12mm). For planetary viewing, many observers prefer the comfort of the Delos, while deep-sky observers might prefer the wider field of the Nagler.\u003c\/p\u003e\n\u003c\/div\u003e\n\u003cdiv class=\"DAV-accordion\"\u003e\n\u003ch3 class=\"DAV-accordion-Q\"\u003eWill this eyepiece work on a very fast Dobsonian telescope?\u003c\/h3\u003e\n\u003c\/div\u003e\n\u003cdiv class=\"DAV-accordion-A\"\u003e\n\u003cp\u003eYes, but it will provide extremely high magnification that may exceed what the atmospheric seeing or the telescope's optics can support. It will perform best when used with a Paracorr to correct for coma inherent in fast Newtonian reflectors.\u003c\/p\u003e\n\u003c\/div\u003e\n\u003cdiv class=\"DAV-accordion\"\u003e\n\u003ch3 class=\"DAV-accordion-Q\"\u003eWhat's the main trade-off with the Delos 3.5mm?\u003c\/h3\u003e\n\u003c\/div\u003e\n\u003cdiv class=\"DAV-accordion-A\"\u003e\n\u003cp\u003eIts main limitation is its dependence on steady atmospheric seeing. The high power it delivers will magnify any atmospheric turbulence, so it can only be used to its full potential on nights of good to excellent seeing. It is not an all-purpose, every-night eyepiece.\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\u003eTV-EDL-03.5\u003c\/td\u003e\n\u003c\/tr\u003e\n\u003ctr\u003e\n\u003ctd\u003eFocal Length\u003c\/td\u003e\n\u003ctd\u003e3.5mm\u003c\/td\u003e\n\u003c\/tr\u003e\n\u003ctr\u003e\n\u003ctd\u003eBarrel Size\u003c\/td\u003e\n\u003ctd\u003e1.25\"\u003c\/td\u003e\n\u003c\/tr\u003e\n\u003ctr\u003e\n\u003ctd\u003eApparent Field of View (AFOV)\u003c\/td\u003e\n\u003ctd\u003e72°\u003c\/td\u003e\n\u003c\/tr\u003e\n\u003ctr\u003e\n\u003ctd\u003eEye Relief\u003c\/td\u003e\n\u003ctd\u003e20mm\u003c\/td\u003e\n\u003c\/tr\u003e\n\u003ctr\u003e\n\u003ctd\u003eWeight\u003c\/td\u003e\n\u003ctd\u003e7.4 oz \/ 209 g\u003c\/td\u003e\n\u003c\/tr\u003e\n\u003ctr\u003e\n\u003ctd\u003eField Stop Diameter\u003c\/td\u003e\n\u003ctd\u003e4.3mm\u003c\/td\u003e\n\u003c\/tr\u003e\n\u003ctr\u003e\n\u003ctd\u003eCoatings\u003c\/td\u003e\n\u003ctd\u003eFully Multi-Coated\u003c\/td\u003e\n\u003c\/tr\u003e\n\u003ctr\u003e\n\u003ctd\u003eParfocal\u003c\/td\u003e\n\u003ctd\u003eYes, with Tele Vue Group \"A\" eyepieces\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\u003cdiv\u003e\n\u003cp class=\"DAV-item-title\"\u003eTele Vue Delos 3.5mm 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\u003cdiv\u003e\n\u003cp class=\"DAV-item-title\"\u003eTop Dust Cap\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\u003cdiv\u003e\n\u003cp class=\"DAV-item-title\"\u003eBottom Dust Cap\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\/Tele_Vue_Delos_3.5mm_Eyepiece_Manual.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\u003cli\u003e\n\u003ca href=\"https:\/\/davidastro.com\/pages\/tele-vue-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":51223879057693,"sku":"TV-EDL-03.5","price":438.0,"currency_code":"USD","in_stock":true}],"thumbnail_url":"\/\/cdn.shopify.com\/s\/files\/1\/0753\/5280\/1565\/files\/Tele_Vue_Delos_3.5mm_Eyepiece_1.jpg?v=1777515020","url":"https:\/\/davidastro.com\/fr-eu\/products\/tele-vue-delos-3-5mm-72-degree-eyepiece","provider":"David Astro","version":"1.0","type":"link"}