Chapter 16, Problem 58A

To determine

To explain: The reason for painting black inside binoculars and cameras.

Answer to Problem 58A

To avoid the reflection of light during the observation and capturing of image, inside of binoculars and cameras are painted black.

Explanation of Solution

Introduction:

Binocular is an optical instrument which is used to observe the distant objects. Binoculars contains two telescopes fixed side-by-side and pointing in the same direction so that an observer can use both the eyes at the same time to see the distant objects. And, hence binoculars can give three-dimensional view of the distant objects.

Camera is an optical instrument which is used to record the image. Basically, camera is a sealed box with a small hole (aperture) which permits light rays to capture an image of an object on the surface of a light sensitive material (photographic film).

Insides of binoculars and the cameras are painted black. Because it is well known that black doesn’t reflect any light incident on it instead black absorbs all the light incident on it. Light reflection causes interference effect which destructs the observation of far objects using binoculars and capturing an image of an object by camera. To avoid the reflection of light during the observation and capturing of image, inside of binoculars and cameras are painted black.