Compare Televue Tele Vue 3.5mm Nagler Type 6 1.25 Eyepiece (en6035) to Televue (ERD-06.0) (ERD060)

By limiting the field to 60 deg. (a Radian = 57.3 deg.) and establishing a uniform 20mm eye-relief, Tele Vue reworked the Nagler concept using the latest glass types to achieve optimum full field sharpness, freedom from distortion, freedom from ghosting (for critical planetary viewing) along with a unique adjustable eyeguard assembly which Tele Vue calls "Instadjust" Instadjust was developed from the need for proper eye position for non-eyeglass wearers. It is essential, since with Radian's long eye-relief, non-eyeglass wearers would easily tend to get too close to the eyepiece, resulting in vignetting the field, just as you would moving out from the exit pupil. The click-stop, Instadjust eyeguard permits fast, accurate positioning of the eye to the exit-pupil with maximum suppression of environmental stray light. Less