Lens that captures the light from the observed object and causes it to converge to form a magnified inverted image.
body
Cylindrical body of the binoculars that houses the optical system and through which the light rays pass.
focusing ring
Ring on each eyepiece for manually correcting for the difference between the user’s eyes.
central focusing wheel
Focusing ring for both the objective lenses; it is used to manually adjust the sharpness of the image.
hinge
Mechanism for adjusting the distance between the eyepieces to the user’s eyes.
Porro prism
Dual-prism system (blocks of glass at right angles) found in most binoculars; it diverts the light rays toward the eyepiece to correct the inverted image formed in the objective lens.
lens system
Optical system made up of a set of lenses through which light passes to transmit a magnified image of an object to the eye.
eyepiece
Optical disk or system of disks through which the eye sees the image produced by the lens.
