Tele Vue is known for its in-house eyepiece and telescope designs by Al Nagler; the development of the Ethos series brings new meaning to the term “in-house.” The concept for this eyepiece series was proposed by Tele Vue President David Nagler, with performance parameters giving it the fundamental characteristics (the ethos) of a Tele Vue eyepiece: high contrast, comfortable eye relief and full field sharpness. Control of astigmatism, field curvature, lateral colour, angular magnification distortion correction, and low pupil sensitivity for daytime use were specified criteria.
Following Tele Vue’s philosophy of pushing the state of the art, long-time Tele Vue employee and optical design protégé Paul Dellechiaie took up the challenge and designed the basic eyepiece form. Under Al’s guidance, Paul tweaked his design to fulfill the original goals.
While sharpness is inherent to the optical design, contrast is maximized through the intelligent use of flat finished baffles and ultra low reflectance, high efficiency coatings tuned to the composition of each element.
Tele Vue Ethos 8mm
The Tele Vue Ethos 8mm was first demonstrated at NEAF in 2008. In addition to matching all the key performance criteria of its 13mm sibling, the new 8mm version is parfocal in 1¼” focusers with Radians, Plössls, Type 6 Naglers and 1¼” Panoptics.
Its lighter weight and smaller diameter than the 13mm Ethos makes the 8mm suitable for anyone using a binocular viewer. A perfect eyepiece for terrestrial viewing with a short refractor. Comparing an 8mm Ethos to an 8–24mm Zoom eyepiece, the 8mm Ethos has the power of the 8mm Zoom and 83% of the field of the 24mm setting!
Tele Vue is still the leader in high performance, wide angle eyepieces for astronomy. There will always be cheap imitators, but astronomers the world over agree Tele Vue eyepieces are simply the best. One look is all it takes…come and see for yourself!
Tele Vue is known for its in-house eyepiece and telescope designs by Al Nagler; the development of the Ethos series brought new meaning to the term “in-house.” The concept for this eyepiece series was proposed by Tele Vue President David Nagler, with performance parameters giving it the fundamental characteristics (the ethos) of a Tele Vue eyepiece: high contrast, comfortable eye relief and full field sharpness. Control of astigmatism, field curvature, lateral colour, angular magnification distortion correction, and low pupil sensitivity for daytime use were specified criteria.
Following Tele Vue’s philosophy of pushing the state of the art, long-time Tele Vue employee and optical design protégé Paul Dellechiaie took up the challenge and designed the basic eyepiece form. Under Al’s guidance, Paul tweaked his design to fulfill the original goals.
While sharpness is inherent to the optical design, contrast is maximized through the intelligent use of flat finished baffles and ultra low reflectance, high efficiency coatings tuned to the composition of each element.
Introduced at the 2007 Northeast Astronomy Forum, Tele Vue once again broadened the amateur astronomer’s perspective on the universe with: 100° of pure Tele Vue quality. The field area of this new eyepiece is more than 50% larger than an 82° field. The Tele Vue Ethos is essentially multiple eyepieces, delivering the true field size of a longer focal length, narrower apparent field eyepiece with the benefits of higher power and darker sky background.
Tele Vue Ethos 8mm Specifications
Focal Length
|
8mm |
| Apparent Field |
100° |
Eye Relief
|
15mm |
Effective Field Stop Diameter
|
13.9mm |
Barrel Size
|
2″ / 1.25″ |
| Weight |
431g |
Related Links
Instruction Sheet
Eyepiece Distortion
Technical reference on rectilinear and angular magnification distortion.
Majesty Factor
Compare eyepieces by quantifying contrast, power, and apparent field.
