| 摘要 |
<p>An electronic flash unit has a flash tube and a flash circuit which includes an internal light sensor that interrupts the supply of electricity to the flash tube when it senses that the flash light reflected from an object exceeds a predetermined threshold value. The unit also has a connector for connecting it to an external light sensor and an arrangement for disconnecting the internal sensor from the circuit when connection is made to an external sensor, and vice versa. An adapter circuit is connected to the connector and allows the unit to be used with a camera having its own built-in light sensor so that, when the unit is used with such a camera, the camera sensor performs the function otherwise performed by the internal sensor of the unit.</p> |
