![optics - How can I increase the flange focal distance (back focal length) of DSLR lens? - Photography Stack Exchange optics - How can I increase the flange focal distance (back focal length) of DSLR lens? - Photography Stack Exchange](https://i.stack.imgur.com/jvzLX.png)
optics - How can I increase the flange focal distance (back focal length) of DSLR lens? - Photography Stack Exchange
![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
![Lens Focal Length and F-stop | Digital Camera Know-Hows | Digital Camera | Digital AV | Support | Panasonic Global Lens Focal Length and F-stop | Digital Camera Know-Hows | Digital Camera | Digital AV | Support | Panasonic Global](https://av.jpn.support.panasonic.com/support/global/cs/dsc/knowhow/common/img/knowhowfig01_01l.png)
Lens Focal Length and F-stop | Digital Camera Know-Hows | Digital Camera | Digital AV | Support | Panasonic Global
![field of view - How to calculate the correct focal length needed for a subject of a given size and distance? - Photography Stack Exchange field of view - How to calculate the correct focal length needed for a subject of a given size and distance? - Photography Stack Exchange](https://i.stack.imgur.com/t66NU.png)