 |
| |||
| back focal length (distance from the centre of a lens to its principal focus on the image side); image side focal length (distance from the centre of a lens to its principal focus on the image side); second focal length | |||
The server is undergoing maintenance and the site is working in read-only mode. Please check back later.">Add | The server is undergoing maintenance and the site is working in read-only mode. Please check back later.">Report an error
| Get short URL | Language Selection Tips