FE lock is simply obtaining a proper flash exposure, pushing the right button to lock in that exposure.
就是先获得恰当的闪光曝光值，压下闪光曝光锁按钮，锁定这个曝光值。
To make this work, use the partial metering 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。
The speedlight will pre-flash that area and lock that exposure into memory. I might caution you that you have 16 seconds to then recompose and take the shot.
闪光灯会预闪并把曝光值记忆下来，注意你只有16秒的时间重新构图拍摄。
Furthermore, with E-TTL II cameras, flash metering is no longer linked to the AF point you're using - this reduces exposure errors if you prefer to lock focus and re-compose.
另外，使用支持e-TTLII的相机时，闪光的测光不再与当前对焦点联动-这降低了锁焦和重新构图时发生曝光错误的机会。
Furthermore, with E-TTL II cameras, flash metering is no longer linked to the AF point you're using - this reduces exposure errors if you prefer to lock focus and re-compose.
另外，使用支持e-TTLII的相机时，闪光的测光不再与当前对焦点联动-这降低了锁焦和重新构图时发生曝光错误的机会。
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