| 摘要 |
A CPU 114 of a lens device 100 having an EC device 104 turns on an LED 108 after controlling the transmittance of the EC device 104 to a maximum value. The CPU 114 acquires an output signal level of a PH 109 which receives part, passing through the EC device 104, of light emitted from the LED 108 and sets the acquired output signal level as a reference transmittance. In response to an instruction that specifies a multiplication factor by which to multiply the reference transmittance, the CPU 114 controls the voltage supplied to the EC device 104 so that the output value of the PD 109 becomes equal to the reference transmittance multiplied by the multiplication factor. |
