| 摘要 |
The system uses a processor to determine focal settings within a permitted range, according to the angle of sight selected. The system provides control of an objective (101) with variable focus, by movement of a variable focal length part (Z) and a focus part (F). A circuit (5) is provided which converts the information relating the variable focus into corresponding information regarding the angle of sight. An arithmetic circuit compares the information with a permissible angle of sight, and provides corresponding control information for the focal length adjustment which must be used with this particular setting. This enables adjustment of the focus of the system. The arithmetic circuit is also able to determine maximum and minimum permitted settings, by reference to stored information relating to focus adjustment and angle of sight. |
