Generally it includes three steps: light intensity measurement, scenario analysis and exposure compensation. And auto-exposure has optics-implemented way and electronic-implemented way.
一般包括光强测量、场景分析和曝光补偿等三个步骤，可以用光学和电子学两种方式来实现。
2
The “P” mode is in reality a semi auto mode, that is the P is the first in the line of programmed modes, but in practical use, the camera still continues to do autoexposure.
It has a wide-aperture lens to capture as much light as possible, and the technology requires no clunky auto-focus mechanism. It adjusts exposure time automatically.