Optics.
1. a plane through a focal point and normal to the axis of a lens, mirror, or other optical system. Cf. principal plane .
2. the transverse plane in a telescope where the real image of a distant view is in focus.
[ 1890-95 ]
Optics.
1. a plane through a focal point and normal to the axis of a lens, mirror, or other optical system. Cf. principal plane .
2. the transverse plane in a telescope where the real image of a distant view is in focus.
[ 1890-95 ]
Random House Webster's Unabridged English dictionary. Полный английский словарь Вебстер - Random House . 2012