Definition of Huygens eyepiece in English:

Huygens eyepiece

noun

Optics
  • A simple eyepiece consisting of two separate planoconvex lenses, used chiefly in refracting telescopes of long focal length.

    • ‘The Ramsden eyepiece is essentially a Huygens eyepiece with the bottom lens element reversed.’
    • ‘This is a variation on the Huygens eyepiece, and has a two piece achromatised eye lens.’
    • ‘The binocular or optional trinocular viewing head is equipped with several Huygens eyepieces and can be rotated to any position and secured with a lock screw.’
    • ‘A few minutes of adjusting the tripod and selecting from my wide assortment of Huygens eyepieces, I had the projection system set up.’
    • ‘These are better than Huygens eyepieces, but not by much.’