The baader hyperion eyepiece 21mm delivers a 68deg field of view with 20mm eye relief hyperion eyepieces feature baaders phantom group multicoating sharpening contrast and ensuring excellent light transmission each eyepiece has both a 2 and 125 barrel and is equipped with both a m43 and sp54 photographic thread housed under a protective silicone rubber ring the photographic threads may be used in conjunction with an adapter ring in order to attach to a wide variety of photographic eq