Question

When you focus a camera, you adjust the distance of the lens from the film. If the camera lens acts like a thin lens, why can it not be kept at a fixed distance from the film for both near and distant objects?

a) The lens would block the passage of light.

b) Different distances are needed for different magnifications.

c) The lens would become too heavy.

d) The lens would lose its ability to refract light.

Answer 1

A camera lens cannot be kept at a fixed distance from the film for both near and distant objects due to the need for different distances for different magnifications.

Step-by-step explanation:

When you focus a camera, you adjust the distance of the lens from the film. In the case of a camera lens acting like a thin lens, it cannot be kept at a fixed distance from the film for both near and distant objects due to the need for different distances for different magnifications.

To focus on a near object, the lens needs to be moved farther away from the film in order to increase the image distance and achieve a larger magnification. On the other hand, to focus on a distant object, the lens needs to be closer to the film to decrease the focal length and achieve a smaller magnification.