In just a few years, every door lock, card reader, video camera, vehicle, power meter, and light switch will have an IP address — at least in the business world.
数年之内，至少在商业领域，每一个门锁，每一个读卡器，每一个摄像头，电表，甚至是电灯开关都会被赋予一个IP地址。
A second of time, for instance, is now defined in terms of an electron transition of the cesium atom. And the meter is tied to the speed of light.
比如说，秒就是根据铯原子内部的电子跃迁时间来下的定义，而米的定义则和光速有关。
Tip: For spark in a backlit portrait or silhouette, try compositions that include the light source. This can drive your meter crazy, though, so bracket your exposures.
小提示：在拍摄背光照明的人像或剪影时，试着将光源纳入构图中，但是这样会导致测光表读数不准，因此可以尝试使用包围曝光法。
应用推荐