Orion Epic ED2 Series Eyepieces
Orion Epic ED2 Series eyepieces use a special grade of glass that
provide better refractive properties compared to standard optical glass. ED
stands for "Extra-low Dispersion". ED glass is the same type used in many
camera lenses and high-end refractor telescopes that cost thousands of
dollars. Orion Expanse Wide Field Eyepieces are recommended as well.
Orion has designed the Epic Series using a six-element lens design, where
by two of the elements are crafted from ED glass. This provides a wonderful
20mm of eye relief with greatly reduced chromatic aberration and incredible
sharpness.
All Epic ED2 Orion eyepieces are fully coated for maximum image
brightness, for increased contrast the lens edges are blackened. Little to
no refocusing is needed when changing from one eyepiece to another because
the series is parfocal. For protection each piece comes with two end caps
and a tough plastic tube case.