In addition to matching all the key performance criteria of its 13mm sibling, the new 8mm version is parfocal in 1.25" focusers with Radians, Plössls, Type 6 Naglers and 1.25" Panoptics. Further, its lighter weight and smaller diameter than the 13mm Ethos makes the 8mm suitable for anyone using a binocular viewer.

In 1.25" mode, if you use Tele Vue's "high-hat" 2"-1.25" adapter, it will be parfocal with Tele Vue's Plössls, Radians, Type 6 Naglers, Nagler Zooms, 1.25" Panoptics and 8mm ETHOS.

The 10mm Ethos delivers: 100° apparent field (50% larger in area than 82° Naglers), comfortable eye-relief, (accepts DIOPTRX eyesight astigmatism correctors), distortion correction, high contrast and on-axis sharpness for planetary viewing.

Al Nagler eagerly pushed Ethos designer Paul Dellechiaie to extend the new 3.7mm focal length to reach 110°, the same field as the LEM Simulator optics Al designed 45-years ago to train NASA astronauts for lunar landings.

The new 4.7mm 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.

We have not specifically endorsed the 13mm Ethos for Bino-Vue use because of the large diameter barrel. Even so, we were advised by Mike Harvey at the Winter Star Party (February 2008) that only 1-person in 25 had interpupilary limits with the bino'd Ethos (63.5-mm for the initial production 13mm).

The 17mm ETHOS is an ideal complement to the 31mm Nagler Type-5. They are parfocal (both have focus locations about 3/8" above shoulder) and the 31mm Nagler Type-5 has exactly twice the true field area.

Maximize your "spacewalk" experience with the 21mm Ethos. Transform your passage through the Milky Way with the 21mm’s nexus of contrast, power and field. Larger deep sky objects and rich star fields are its natural playground. Looking on-axis your field-of-vision is filled with 100º of stars, however wherever you chose to concentrate your attention you’ll see sharpness and richer contrast.