TeleVue Ethos 21mm 100° 2″ Eyepiece
A few years ago, most observers were happy with eyepieces offering a 50° to 60° field of view. The TeleVue Ethos changes that completely. It delivers a 100° apparent field of view - around 50% more than a quality 82° eyepiece, and twice that of a standard wide-angle design. The tunnel effect disappears. Looking through the Ethos feels like looking directly at the night sky, not peering through a small opening.
Sharp from centre to edge
A wide field of view is only useful if the image holds up across the whole area. The Ethos solves this with a refined optical design combined with high-quality fully multi-coated lenses on every element. The result is high contrast and a sharp image from the centre all the way to the edge - even on fast telescopes at f/4. You will see fine detail on planetary surfaces as well as subtle structure in nebulae and galaxies.
Comfortable viewing, practical design
The 15mm eye relief makes extended observing comfortable, including for eyeglass wearers. The adjustable rubber eyecup adapts to different viewing preferences and blocks stray light. The eyepiece has a filter thread and is compatible with optional camera adapters.
The Ethos eyepieces are parfocal - you can swap between different focal lengths in the Ethos range without needing to refocus. This makes switching eyepieces during a session much faster and more convenient.
Recognised by experts
The Ethos range has received repeated recognition in specialist publications. Sky & Telescope magazine awarded it the "HOT Product" award four times in a row.
Technical specifications
| Parameter |
Value |
| Focal length |
21mm |
| Apparent field of view |
100° |
| Barrel diameter |
2″ |
| Eye relief |
15mm |
| Lens coating |
Fully multi-coated (all elements) |
| Filter thread |
Yes |
| Parfocal with other Ethos eyepieces |
Yes |
| Suitable for eyeglass wearers |
Yes |
| Compatible with fast telescopes |
From f/4 |
