To make this work, use the partialmetering mode (or spot metering mode) over the subject where you want to lock the flash output then press the asterisk (*) button.
相机的测光方式要设置在局部测光或点测光方式，测光点对着你想要锁定曝光值的目标，按下锁定钮。
2
In power system, it can excite partial parallel resonance or serial resonance, enlarge the harmonic wave, trigger relay protection system in error and disturb electric power energy metering equipment.