Question

Which action of prism in used in prism binocular and certain type of camera ?

• A. It deviate a ray of light through ${180}^{\circ }$
• B. It erect the inverted image without deviation
• C. It deviate a ray of light through ${90}^{\circ }$
• D. All of the above

Answer 1

The correct option is A It deviate a ray of light through ${180}^{\circ }$

Binoculars have a pair of prisms (large wedges of glass) inside them to rotate the image through 180 degrees. One prism rotates the image through 90 degrees (flips it onto its side), then the next prism rotates it through another 90 degrees (flips it onto its side again), so the two prisms effectively turn it upside down. The prisms can either be arranged in a back-to-back arrangement or at 90 degrees.