Second hand but in excellent condition complete with TeleVue Dioptrx.
TeleVue Panoptic premium-quality eyepieces have six lens elements, with an ED (extra low dispersion glass) element for exceptional contrast and a very wide field. The design provides relatively long eye relief, with up to five times the field edge correction of older wide field designs when used on fast focal ratio scopes.
They are designed for low to medium power use down to f/4 with any telescope. They can be exceptional with fast focal ratio Dobsonian reflectors, particularly when combined with a TeleVue 2" Paracorr coma corrector to correct the coma otherwise visible in the very wide fields of longer focal length eyepieces. Their wide fields allow longer undisturbed observing time than conventional eyepieces before a Dobsonian has to be moved to reacquire an object.
The Panoptics approach the performance of TeleVue Nagler eyepieces in image quality, although with a narrower field of view.
The Panoptics are fully multicoated, with blackened lens edges for high contrast. All have soft fold-down rubber eyecups, with rubber grip rings for comfort in cold weather, and all are threaded for filters.
A telescope's focuser is used to compensate for your near- or far-sightedness; DIOPTRX™ compensates for your astigmatism. These units attach and lock onto the tops of over 20 long eye-relief Tele Vue eyepieces to achieve the sharpest full-field viewing possible. DIOPTRX™ models are available in ¼ to 3½ diopter (¼ steps from ¼ to 2½ diopters, then ½ diopter steps to 3½-diopters), and are rotatable for tuning to the best orientation. A series of engraved letters on the barrel helps to monitor orientation. Simply choose the DIOPTRX™ model that matches your eyeglass prescription for astigmatism. All lenses are multi-coated glass in anodized aluminum housings with rubber eyeguards.
Benefits of using Dioptrx over eyeglasses are:
1. You're more likely to see a sharper, higher contrast image, because:
A. The Dioptrx is always completely aligned to the eyepiece optics, eliminating aberrations from a decentered mismatch of eyeglass power and astigmatic axis.
B. Dioptrx can be rotated to exactly compensate for the astigmatic axis angle in real time, since both head angle and age can vary your eyesight astigmatic angle.
C. Dioptrx likely has better multi-coatings than eyeglasses, and certainly is better in transmission and reflection reduction than uncoated eyeglass.
D. Dioptrx is more likely to be cleaner than eyeglasses, which may have scratches and smudges from constant use and wear and tear.
E. Dioptrx allows seeing your normal maximum contrast that eyeglasses can diminish (remove your eyeglasses and see how contrast improves in normal vision).
2. You're more likely to see the full field in 100° Ethos eyepieces because your eyeglasses are more limiting in "effective eye-relief".
How to Choose DIOPTRX™ Models
Your prescription may look like this, with different numbers.
SPHERICAL CYLINDER AXIS
Right Eye O.D. +1.50 -0.50 45
Left Eye O.S. -0.50 +1.50 135
Simply choose DIOPTRX™ to match the cylinder (astigmatism) value of your preferred viewing eye. In the example above, you would choose 0.5 diopter model for your right eye and 1.5 diopter model for your left eye.
Ignore spherical and axis values.
Ignore all ± signs.