The 10mm Delos eyepiece from Tele Vue features a 20mm eye relief and 72deg. apparent field of view. The Delos eyepiece design was conceived as a narrower field alternative to Ethos eyepieces. Reducing the field to 72deg. allowed freedom to increase eye-relief, while controlling pupil aberrations, all without making the eyepiece too large. With Ethos performance standards as benchmarks, the Delos design achieves full field sharpness, virtually perfect theta distortion mapping and color neutrality.
Image fidelity is maximized utilizing glass matched multi-coatings and anti-reflection surfaces throughout the eyepiece. Contrast is further enhanced with a new continuously adjustable height eyeguard system that can be locked in any position. Since the Delos eye-lens measures a quite large 35mm in diameter, preventing stray light from the reflecting off the first surface and extraneous light from entering your eye pays off in a nice increase in perceived contrast.
The eyeguard's sliding action allows for positioning the soft rubber eyeguard at the ideal height to suit the observers preference. Indicator marks on the eyepiece body are handy reference guides for setting your perfect position. The eye-guard can also rotate for Dioptrix users.