Ye!djustments, Style of binoculars: porro or roof prism design – Carson Makalu 10x42 Binoculars User Manual

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Style of Binoculars: Porro or Roof Prism Design

Binoculars come in two distinct styles in which the design is dependent upon the type of
prism system used. The image that passes through a binocular is upside down (a
function of the lens) and needs to be corrected. The prism is the optical glass inside a
binocular whose purpose is to “invert the image”.

Roof Prism Systems:

The prisms overlap closely allowing

the objective (front) lens to line up directly with the eyepieces.
The result is a slim, streamlined shape in which the lenses
and prisms that magnify and correct the image are in a
straight line.

%YE!DJUSTMENTS

(OWTOADJUSTFORDISTANCEBETWEENYOUREYES

The distance between the eyes, called “interpupillary

distance,” varies from person to person. To achieve perfect alignment of lens to eye, follow these simple steps:
1. Hold your binoculars in the normal viewing position
2. Grasp each barrel firmly. Move the barrels closer together

or farther apart until you see a single circular field.

Always reset your binoculars to this position before using.

2OOF0RISM3YSTEM

the prisms overlap closely allowing the objective (front)

lens to line up directly with the eyepieces. The result is a slim, streamlined

shape in which the lenses and prisms that magnify and correct the image

are in a straight line.

0ORRO0RISM3YSTEMS

the objective lens is offset from the eyepiece.

Light is redirected through the binocular internally. The result is a shorter,

stockier shaped binocular. In general, porro prism binoculars offer a wider

field of view. Most zoom binoculars use the porro prism system.

objective lens

eyepiece