![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
![The focal length of a normal eye-lens is about:$(a){\\text{ 1mm}} \\\\(b){\\text{ 2cm}} \\\\(c){\\text{ 25cm}} \\\\(d){\\text{ 1m}} \\\\ $ The focal length of a normal eye-lens is about:$(a){\\text{ 1mm}} \\\\(b){\\text{ 2cm}} \\\\(c){\\text{ 25cm}} \\\\(d){\\text{ 1m}} \\\\ $](https://www.vedantu.com/question-sets/23766a8b-704b-4a02-9898-45078c04e63b6462374204689754885.png)
The focal length of a normal eye-lens is about:$(a){\\text{ 1mm}} \\\\(b){\\text{ 2cm}} \\\\(c){\\text{ 25cm}} \\\\(d){\\text{ 1m}} \\\\ $
![F-number, explained by RP Photonics Encyclopedia; light throughput, focal length, depth of field, working f-number F-number, explained by RP Photonics Encyclopedia; light throughput, focal length, depth of field, working f-number](https://www.rp-photonics.com/previews/f_number.png)
F-number, explained by RP Photonics Encyclopedia; light throughput, focal length, depth of field, working f-number
![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)