| 摘要 |
The difference in voltages across two photoconductors, one exposed to direct scene light and the other to scene light that has passed through the camera objective, drives a moving-coil instrument, the pointer of which controls a movable mask that more and more shields the second photoconductor until the voltages across the two photoconductors are approximately equal. A capacitor then charges through the second photoconductor to a voltage that closes the shutter. |
