The 8mm TeleVue Delos puts the performance of the original ground-breaking TeleVue 9mm Ethos eyepiece - high contrast, a neutral color balance, and full field sharpness - into a 72° field eyepiece with a long 20mm eye relief that makes it ideal for eyeglass wearers. The majority of eyepieces in this focal length range tend to have a shorter eye relief that makes them difficult to use with eyeglasses, but that is not an issue with the Delos. With its long 20mm of eye relief, the full 72° apparent field of the Delos is easily usable for those who wear glasses to control their astigmatism. Even if you don't wear glasses to observe, the Delos is simply a comfortable high power eyepiece to use.
There is an adjustable height eyeguard with a soft rolldown eyecup to shield the eye from ambient light (from a neighbor's security light, for example) and improve the image contrast. The eyeguard height can be locked in place at any point desired. The Delos can be used with TeleVue Dioptrx astigmatism correcting lenses, should you choose to observe sans eyeglasses.
As a longer eye relief/modestly higher power 72° field version of the justly-famous 100° field 9mm TeleVue Ethos, the 8mm Delos has the visual virtues that astronomers have come to expect from an Ethos - well-controlled astigmatism, field curvature, lateral color, angular magnification distortion correction, and low pupil sensitivity (kidney bean effect) for daytime use.
The 8mm Delos has a 1.25" barrel that is threaded for standard 1.25" eyepiece filters. A safety groove is machined into the chrome barrel to engage your focuser thumbscrew. This will help prevent the eyepiece from falling should the thumbscrew accidentally loosen while observing. The main eyepiece barrel is narrow enough to allow most observers to use a pair of 8mm Delos in a binoviewer. Rubber grip rings provide a sure grip in cold weather when wearing gloves or mittens. Dust covers are provided for both ends of the eyepiece.
