TeleVue Ethos Eyepieces

The Amazing TeleVue Ethos Eyepieces

Our first encounter with the original 13mm Ethos eyepiece was at the 2007 Northeast Astronomy Forum. Al Nagler called us over to have a look at something new, just before the doors were opened to the public. There in the focuser of an NP-101 we found an eyepiece with familiar Tele Vue green lettering yet a very unfamiliar shape. One way to describe it would be to say that someone had taken a familiar 12mm Nagler and stretched it lengthwise. Stepping up to the eyepiece, we were introduced an incredible 100º apparent field. The target images provided by Tele Vue showed the image to be tack sharp across the entire field of view, even in the fast f/5.4 NP-101 refractor. The Tele Vue Ethos performs the function of 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. Later that year, Tele Vue toured the country demonstrating the Ethos eyepiece at regional star parties. Customer feedback from this field testing was nothing short of incredible. The general consensus of customers who have actually observed with this eyepiece is "how soon can you get me one?" Clearly TeleVue has raised the bar once again with the introduction of the new Ethos eyepiece.

Announcing the Amazing Ethos!

Tele Vue is known for its in-house eyepiece and telescope designs by Al Nagler. The amazing TeleVue Ethos eyepiece offers an incredible 100 degree apparent field of view. Their latest eyepiece brings new meaning to the term “in-house.” The concept for this eyepiece was first proposed by Tele Vue President David Nagler, with performance parameters giving it the fundamental characteristics (the ethos) of a TeleVue eyepiece: high contrast, comfortable eye relief and full field sharpness. Control of astigmatism, field curvature, lateral color, angular magnification distortion correction (technical reference), 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.

Spring 2010: The TeleVue Ethos Family is Now Complete

Following the original 13mm Ethos, the 8mm Ethos began shipping in June of 2008. Then in September of 2008 TeleVue announced two additional members of the Ethos family: the 6mm and 17mm. Skies Unlimited was fortunate to host the east coast debut of these new Ethos eyepieces at our Mid-Atlantic Astronomy Expo on October 11th. The field of view served up by the 17mm Ethos in combination with a TV-85 refractor was nothing short of astounding. The 6mm and 10mm Ethos arrived in February and April of 2009, respectively. The largest member of the familiy, the 21mm Ethos was announced at the Stelafane convention in August of 2009 with delivery in December 2009. We received half of our initial order in December and all of those eyepieces were sold on the same day. The final member of the family, the 3.7mm Ethos SX was added in the Spring of 2010. We do not anticipate the release of any furhte members of this family, but who knows, we could be wrong.