Tele Vue 13mm Ethos Eyepiece - Manual (Page 2)

Tele Vue Optics, Inc., 32 Elkay Drive, Chester, NY 10918 845-469-4551 V4/3/200
Note: when using a 1¼" filter in ETHOS, be careful not to accidentally set the Paracorr’s tunable top
to its lowest setting, as the bottom of the filter might contact the Paracorr’s upper lens. It’s best to
thread a 2" filter onto the front of the Paracorr, or add our EBX-2120 2" extension tube to the 2"
barrel of ETHOS, for general use. For higher magnifications with a 100º field, use Tele Vue Barlows
and Powermates. When using ETHOS in 2" Powermates, use its 2" barrel.
Note: As with the Paracorr, do not use a 1¼" filter when using a 2X Powermate, as it will contact the
upper lens in the 2X Powermate. Again, the best solution is to use 2" filters in front of the
Powermate.
If you have eyesight astigmatism, you can add Tele Vue’s Dioptrx Astigmatism Corrector to ETHOS,
instead of using eyeglasses, to get the sharpest view possible (check dioptrx.com for more details).
We wish you years of exciting and Majestic deep sky viewing with ETHOS, and we welcome
comments on your personal experiences.
Telescope Magnification (x) True Field (°) Exit pupil (mm)
TV-60, TV-60is 27.7 3.55 2.17
TV-76 36.9 2.66 2.06
NP-101, NP-101is 41.5 2.37 2.41
TV-85 46.2 2.13 1.86
NP-127is 50.8 1.94 2.50
TV-102, TV-102iis 67.7 1.45 1.51
Approximate dimensions of 13mm ETHOS
A. Length of barrel above reference surface (4.0")
B. Overall length below reference surface (1.6")
C. Length of 2" barrel (1.1")
D. Diameter of black barrel (2.5")
E. Depth of 1¼" barrel (1.1")
F. Approx. location of field stop (0.27")
Reference surface is location of 2" barrel seat