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TeleVue Ethos 8mm 100° Eyepiece - 2" / 1.25"
The Tele Vue Ethos 8mm is a high power powerhouse designed to deliver the ultimate high contrast observing experience. In the Ethos lineup, the 8mm focal length is frequently cited as the sweet spot for deep sky objects that require significant magnification to reveal internal structure. It provides a tight exit pupil that effectively suppresses sky glow, making it a favorite for observers in light polluted areas looking to maximize their telescope's potential.
Observing through the 8mm Ethos offers a breathtaking 100° field that effectively removes the boundaries between you and the cosmos. Whether you are hunting for small planetary nebulae or diving into the intricate lanes of distant galaxies, the 8mm offers the resolution and contrast necessary for demanding visual work. Like its siblings, it is parfocal with the 13mm, 10mm, and 6mm Ethos models for effortless focal length changes.
Unrivaled Contrast and Resolution
The 8mm Ethos is engineered to provide sharp views across the entire 100° expanse. By pushing magnification while maintaining a massive field of view, it allows you to see the big picture without sacrificing the fine details found at the center of the field.
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Planetary Detail: Sharp enough for high resolution views of Jupiter’s GRS or Saturn’s Cassini Division in telescopes with moderate to long focal lengths.
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Globular Cluster Specialist: Ideal for resolving the tightest stellar cores in objects like M15 or M2, where background darkness is key to seeing individual stars.
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Immersive Lunar Views: The 8mm provides a high altitude flyover feel that covers a significant portion of the lunar limb at high power.
Versatile Hybrid Barrel Design
The 8mm Ethos includes the Tele Vue hybrid barrel system, making it compatible with a wide range of equipment. It slides natively into 1.25" focusers for small refractors or 2" diagonals for larger reflectors and SCTs.
To ensure the purest views, every lens edge is blackened and the internal baffles are designed to eliminate stray light. This ensures that even when a bright moon is just outside the field, your view remains free of glare and internal reflections.
Built for Long-Term Comfort
At approximately 0.95 lbs (430g), the 8mm Ethos is slightly lighter and more compact than the 13mm and 10mm versions, making it easier to balance on smaller mounts. It maintains the series standard 15mm eye relief for a comfortable viewing experience.
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Dioptrx Compatibility: Fully compatible with Tele Vue Dioptrx to correct for eyesight astigmatism, allowing for sharp views without wearing glasses.
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Safety Undercut: The barrel is machined with a safety groove to ensure the eyepiece stays securely in your focuser even if the set screw is slightly loose.
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Is the 8mm Ethos better than the 10mm for galaxies?
The choice usually depends on your specific telescope and sky conditions:
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Increased Contrast: The 8mm focal length produces a smaller exit pupil than the 10mm, which darkens the sky background further. This often makes small, faint galaxies easier to detect.
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Detail: For small planetary nebulae or resolving tight globular clusters, the 8mm provides that extra bit of magnification needed to see structural details.
How much eye relief does the 8mm Ethos have?
The 8mm Ethos has 15mm of eye relief, which is the same as all other eyepieces in the Ethos series:
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Consistent Head Position: This allows you to switch between focal lengths in the Ethos line without having to adjust how close your eye is to the lens.
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Eyeglass Use: If you must wear glasses, you may find it difficult to see the full 100° field at once. Most users prefer using the Tele Vue Dioptrx attachment for the best results.
Is the 8mm Ethos parfocal with other eyepieces?
Yes, the 8mm parfocal with the 6mm Ethos model. This means you can swap these eyepieces in and out of your diagonal with little to no refocusing required.
How does the 8mm Ethos perform in an 8" SCT?
In a standard 8" f/10 Schmidt Cassegrain, the 8mm Ethos is an excellent high power tool:
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Magnification: It provides 250x, which is often the maximum usable magnification on nights with good atmospheric seeing.
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Exit Pupil: It yields a 0.8mm exit pupil, which is ideal for resolving the finest planetary and lunar details.
Do I need a Paracorr with the 8mm Ethos?
The requirement for a coma corrector is based on your telescope design:
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Fast Newtonians: For scopes f/4.5 or faster, a Paracorr Type 2 is recommended to keep stars pinpoint sharp to the edge of the 100° field.
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Other Scopes: Refractors and SCTs typically do not require a coma corrector for the 8mm Ethos.
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| Model # |
ETH-08.0 |
| Focal Length |
8 mm |
| Barrel Size |
2" / 1.25" Hybrid |
| Filter Compatibility |
Threaded for 1.25" filters |
| Apparent Field of View |
100° |
| Eye Relief |
15 mm |
| Field Stop Diameter |
13.9 mm |
| Weight |
15.2 oz (0.95 lb / 430 g) |
| Dimensions |
2.1" x 5.8" (53.3 x 147 mm) |
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- TeleVue 5-Year Limited Warranty for Telescopes and Accessories
