8 mm Radian Eyepiece
TeleVue - 8mm Radian Eyepiece
The long eye relief (20mm)
and fairly large (and well corrected) apparent field of view of 60
degrees make the Radian a pleasure to use for planetary and
other high power observing. Sharpness is comparable to all but
the best orthoscopics.
Manufacturer: Tele Vue Optics, Inc. (http://www.televue.com)
Model Type: Radian
Barrel Size: 1.25 in. (32mm)
Focal Length: 8mm
Field Stop Diameter: 8.3mm
Eye Relief: 20mm
Apparent Field of View: 60°
It has Instadjust was developed for maximizing contrast while aiding in proper eye positioning for non-eyeglass wearers. It is essential, since with the Radian's long eye-relief, non-eyeglass wearers could easily get too close to the eyepiece, resulting in vignetting where edge field rays miss your pupil. The push-pull, click-stop adjustment permits fast positioning and maximum suppression of environmental stray light.
Another unique development is the Pupil Guide. It helps non-eyeglass wearers, especially novices, zero-in and stay centered on the exit pupil. The Pupil Guide is included with all Radian and Nagler Type 4s and fits under the soft, fold-down rubber eyeguard