Tele Vue 10mm Ethos Eyepiece - Manual

Tele Vue Optics, Inc., 32 Elkay Drive, Chester, NY 10918 845-469-4551 V4/20/2009
10mm ETHOS EYEPIECE INSTRUCTIONS
Warning: Do not unscrew any sections of the eyepiece, as the lenses
may fall out, thereby voiding the warranty.
Tele Vue 10mm ETHOS Specifications:
Apparent Field: 100º
Focal length: 10mm
Effective Field Stop: 17.7mm
Eye Relief: 15mm (accepts Tele Vue’s Dioptrx astigmatism corrector)
Barrel Size: 2" / 1¼"
Weight: 1.1 lbs.
Thank you for purchasing the Tele Vue 10mm ETHOS, which nicely fills the focal length gap between
8mm and 13mm models. It also becomes the centerpiece of a great 6mm, 10mm and 17mm ETHOS
set.
The 10mm ETHOS fits both 2" and 1¼" focusers or diagonals. Typically, in a 2" focuser, you will
focus “out” a bit (about 3/8" further than a 26mm Nagler Type 5), and in a 1¼" focuser, you’ll focus
“in” about ½" inch further than a 25mm Plössl.
The 10mm is parfocal with the 13mm ETHOS.
Note: the in-travel may prevent focusing in some refractors when using the Tele Vue 60º Everbrite
diagonal, which has an unusually long optical path.
Since it is designed as a 1¼" eyepiece, there is NO optical benefit by using a 2" holder. The 2"
barrel is included just for convenience, but it is also threaded to accept our EBX-2120 2" extension
tube, which allows the use of 48mm filters.
Its 59mm rubber grip diameter makes this model usable in binocular viewers -- for most people.
For 1¼" holders:
1) Back off the lock screw in the 2" barrel section of the eyepiece so it can be fully inserted into the
holder.
2) If the holder has a lock screw, rotate the eyepiece so that the screw slips into the slot in the 2"
section of the eyepiece barrel. Your holder lock screw clamps to the 1¼" barrel of the eyepiece,
while the eyepiece lock screw clamps (if desired) to the outside of your holder for maximum safety.
3) If your holder doesn’t have a lock screw, be sure to clamp the eyepiece lock screw onto the
outside of the holder. Please note that this eyepiece is heavy, and can fall out of holders with a “slip
fit” unless the lock screw is used!
For 2" holders:
1) Remove the eyepiece lock screw (Don’t lose it!)
2) Use the lock screw on your 2" holder, being careful not to let it slip into the slot in the 2" barrel of
the eyepiece.
3) The eyepiece will not “bottom” on Tele Vue 2" diagonals. Be careful if using diagonals by other
manufacturers.
For Newtonians/Dobsonians, we recommend our Paracorr coma corrector to eliminate the mirror
coma in f/5.5 or faster scopes. This permits the same kind of full field sharpness routinely seen in
Tele Vue’s NP-Series refractors. You can use the 10mm ETHOS 2" barrel in the Paracorr with the
tunable top raised to its maximum, mark 1 on Paracorr slot. However, you can get closer to ideal
coma correction by using the 10mm ETHOS in a high-hat 2" to 1¼" adapter (part ACR-2125 or satin
finish ASF-8125) and setting the Paracorr to its full down position, mark 5 on Paracorr slot.