Slow times for Breton despite fast

An exposure determining device comprises a bridge circuit which includes a photoelectric element for receiving light from an object, and first, second and third resistors. The first resistor is variable for controlling the balance of the bridge circuit and for introducing an exposure factor. One end of the first resistor is connected to one end of the photoelectric element, and one end of the second resistor is connected to the other end of the photoelectric element. One end of the third resistor is connected to the other end of the first resistor. Means for detecting the balance of the bridge circuit is provided and includes npn and pnp transistors. The npn transistor has its base connected to the junction between the photoelectric element and the first resistor and has its emitter connected to the other end of the third resistor. The pnp transistor has its base connected to that junction and has its emitter connected to the other end of the second resistor. The detecting means may produce a first and a second signal representing the balance and unbalance of the bridge circuit. A voltage divider is connected between the other ends of the second and third resistors. A third transistor is provided and has its base connected to the voltage divider. Control circuit means is connected to the collectors of the npn and pnp transistors to receive the first and second signals from the detecting means for determining a proper exposure.