Remember above how the flash sends out a pre-flash?

还记得前面提到的闪光灯预闪吗？

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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。

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The flash power calculation is also based on centre-weighted metering of the light reflected by the pre-flash.

闪光灯输出功率的计算仍然是根据预闪反射光的中心加权测量结果。

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The device itself is a fairly standard affair, boasting a 4.3-inch WQVGA display, a 400MHz CPU, 64MB of RAM, an SD card slot, an FM transmitter, Bluetooth, and maps of the US and Canada pre-loaded on the unit's 2GB of internal flash memory -- an RDS-TMC traffic information receiver is also available as an optional accessory.

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This is because the operating system and pre-loaded software are all on the flash memory.

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"Cheesy, pre-scripted, commercialized performances" have spoiled the flash mob's original artistic spark, says Sean Savage, a designer for tablets and mobile devices often credited with coining the term "flash mob" on his blog 'cheesebikini?

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