Optics, Photog.
a mirror or prism that divides a beam of light into two parts by reflecting a part of the beam, used in camera range finders.
[ 1930-35 ]
Optics, Photog.
a mirror or prism that divides a beam of light into two parts by reflecting a part of the beam, used in camera range finders.
[ 1930-35 ]
Random House Webster's Unabridged English dictionary. Полный английский словарь Вебстер - Random House . 2012