The Tele Vue philosophy (ethos, if you will) has always been about inspiring "spacewalk" vistas by creating both the finest "rich field" refractors and wide angle eyepieces. With their minimum 100-deg apparent field of view, full-field sharpness, and exceptionally high contrast, the Ethos eyepiece line is another step in that direction.
The new 4.7mm 110-deg Ethos-SX, like its 3.7mm progenitor, is designed and crafted to combine its exceedingly wide field of view with all the contrast, color-rendition, distortion correction and center-to-edge sharpness needed to achieve that natural view. Compared to a lower power eyepiece with the equivalent TFOV (similar field stop) such as an 11mm Plossl (9.1mm field stop), the greater power - for higher resolution, and smaller exit pupil (for a darker background to enhance contrast) reveals a deep sky experience "even better than you imagined". The 4.7mm is a 1.25" format eyepiece and is parfocal with the wide range of 1.25" Tele Vue eyepieces. 2" adapter included.
All Tele Vue Ethos eyepieces have proprietary tuned full multi-coatings, blackened lens edges, high index glasses, fold-down eyeguards, rubber grip rings, cover for the eyeguard, an undercut in the barrel for extra locking security, and filter threads. All Tele Vue eyepiece lines are proprietary, in-house designs manufactured to their specifications and tolerances. Every eyepiece is individually tested at Tele Vue to ensure it meets high optical and cosmetic standards.
Ethos Series Development History
Tele Vue is known for its in-house eyepiece and telescope designs by Al Nagler; their latest eyepieces 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 color, 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.
|Barrel Size||1.25" (31.7mm) and 2" (50.8mm)|
|Apparent Field of View (Mfg Specified)||110°|
|Eye Relief (Designed)||15mm|
|Filter Threads||Standard 1.25" Filter Thread (M28.5 x 0.6)|
|Blackened Lens Edges||Yes|
|Barrel Safety Recess||Yes|
|Barrel Type||With safety undercut|
|Protective Plastic Storage Container||Yes - Free Agena Eyepiece Container|
|Protective Plastic Storage Container Size||Agena 65x120mm|
|Maximum Width||2.2" (55.9mm)|
|Field Stop Diameter||8.9mm|
|Rubber Eye Guard||Yes|
|Warranty||Limited lifetime warranty|
- Suitable for use with Tele Vue Bino Vue binoviewer