See why others are changing over to the Radian as their eyepiece of choice for planetary observing.
The eyepieces employ the "instajust" eyeguard - "instadjust" was developed for maximising 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.
Radians excel for comfortable viewing at the higher powers needed to study planetary and lunar detail as well as compact deep-sky objects. Their six- to seven-element lens design exhibits the renowned TeleVue quality, providing flat, sharp images over the entire 60° apparent field. Radians are fully multi-coated for superior light transmission, and all are parfocal, eliminating the need to refocus after switching eyepieces.