![Focal Length Formula & Examples | How to Calculate Focal Length - Video & Lesson Transcript | Study.com Focal Length Formula & Examples | How to Calculate Focal Length - Video & Lesson Transcript | Study.com](https://study.com/cimages/multimages/16/2diagram_mirror6688182548421281944.png)
Focal Length Formula & Examples | How to Calculate Focal Length - Video & Lesson Transcript | Study.com
![The value of the focal length of the lens is equal to the value of the image distance when rays are (A) Passing through optical center(B) Parallel to the principal axis.(C) Passing The value of the focal length of the lens is equal to the value of the image distance when rays are (A) Passing through optical center(B) Parallel to the principal axis.(C) Passing](https://www.vedantu.com/question-sets/5e1c89c0-8591-4536-944d-fabfebe37bbe5538049956207025842.png)
The value of the focal length of the lens is equal to the value of the image distance when rays are (A) Passing through optical center(B) Parallel to the principal axis.(C) Passing
![Focal length, explained by RP; focal distance, dioptric power, curved mirror, lens equation, microscope, photographic objective, focus, beam radius Focal length, explained by RP; focal distance, dioptric power, curved mirror, lens equation, microscope, photographic objective, focus, beam radius](https://www.rp-photonics.com/img/focal_length.png)