|TeleVue.com: Article > Eyepiece Specifications|
All Tele Vue eyepieces listed have proprietary tuned full multi-coatings, blackened lens edges, high index glasses, fold-down eyeguards, rubber grip rings, cover for the eyeguard, an undercut in the barrel for extra locking security and filter threads. All Tele Vue eyepiece lines are proprietary, in-house designs manufactured to our specifications and tolerances. Every eyepiece is individually tested at Tele Vue to ensure it meets our high optical and cosmetic standards.
2E / G: # Lens Elements / # Groups
3AF: Apparent Field of View
4G: Parfocal Group, eyepieces with the same letter are approximately parfocal -- require little (if any) refocusing when used together.
5ER: Eye Relief
6Eyepiece Dimensions: see diagram
*Additional adapter required for Dioptrx / Phone Adapter attachment
(negative number is above reference surface)
Tele Vue Eyepiece Notes
True Field in degrees of an eyepiece can be calculated from the field stop diameter and telescope focal length:True Field (°) = 57.3° x eyepiece field stop / telescope focal length
All Nagler, Radian, Ethos, Delos, and DeLite eyepieces have internal focal planes. Field stop diameters and locations are "effective". Radian and Nagler type-4 eyepieces have "Instajust Eyeguards," and "pupil guide" accessory. Delos and DeLite eyepieces have an adjustable/lockable eyeguard.
The 55mm Plössl and 41mm Panoptic eyepieces have an adjustable height (removable) eyeguard.
Also available: 2X and 3X parfocal 1¼" Barlows; parfocal 2.5x and 5x 1¼" Powermates; 2X Big Barlow, 2x and 4x Powermates for 2" focusers. Use Paracorr (1.15X) to correct fast parabolic "Dob/Newts", dramatically sharpens field to take full advantage of Tele Vue eyepiece capabilities.
All dual barrel eyepieces work equally well in 1¼" or 2" focusers.
For your convenience, this table lists older eyepieces that are currently no longer available.