Chapter 30, Problem 27A

If you take a photograph of your image in a plane mirror, how many meters away should you set your focus if you are 2 m in front of the mirror?

To determine

Distance of camera focus to take photograph of your image in plane mirror

Explanation of Solution

Introduction:

Image formed by plane mirror is always virtual, position of image is behind the mirror same as position of an object in front of mirror, image size and object size is also same and image is upright.

To take photograph of an object camera focus must be on an object.

Concept:

If you are 2 m in front of plane mirror, your image is 2 m behind the mirror.

To take photograph of your image camera focus should be on your image hence, you should set focus 4 m away from you.

Conclusion:

To take photograph of your image in plan mirror you should set camera focus 4 m away from you.