Compare Televue 55mm Plossl 2 inch w/Adjustable (epl550) to Televue (ERD-06.0) (ERD060)

This eyepiece has the largest true field possible for 2" eyepiece holders -3 times the field area of any 1 1/4" eyepiece. The focal plane is placed at the end of the barrel to minimize vignetting. Performance with Schmidt-Cassegrains is remarkable since it avoids the image degradation and severe vignetting which occurs when using telecompressors. Long eye-relief and unique adjustable eye guard for eyeglass wearers. Less

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