Question

Q. 12. What is equivalent lens? The equivalent focal
length of two thin lenses in contact is 20 cm. If power of one
lens is (-3D), find the focal length of other lens. ​

Answer 1

Answer:

The concept of 'equivalent lens' occurs when comparing the images taken by cameras with different sized sensors. For the same angle of view, a camera with a smaller sensor will need a lens with a shorter focal length. In normal marketing language, two cameras that have the same angle of view have 'equivalent' lenses.