| 摘要 |
A diaphragm control circuit associated with TTL automatic electronic flash is adapted to be used in a camera of the TTL direct photometry type and capable of photometry of light reflection from film surface. When the electronic flash is mounted on the camera for cooperation therewith, the diaphragm control circuit responds to a brightness of an object being photographed by automatically establishing an aperture value which produces an exposure period synchronized with the operation of the electronic flash. The diaphragm control circuit also assures that the aperture controlling operation takes place reliably over a given time interval so that an aperture value which is less by a given number of steps than the open value is established. |
