Liberal Dictionary English Dictionary
noun Optics.
- a Ramsden eyepiece having an achromatic lens, used in binoculars.
Choosing the Correct Eyepiece | Edmund Optics
Sky-Watcher 6.3mm Kellner Eyepiece [SW-KELLNER6.3] – R453.95
North Star Kellner Okular (6mm, 10mm, 15mm & 25mm)
3 pcs/set SVBONY 1.25