Should the gray, white and black in landscape survey be reduced?

The basic experience of not understanding this formula is not enough, so there is no need to explain it too complicated. Its general meaning is: when shooting scenery, it is enough to measure light according to the standard most of the time, because the general scenery presents a neutral gray effect of 18%; When shooting light-colored scenes, the exposure should be increased on the basis of standard photometric values, and the brighter the light, the more; When shooting a dark scene, the exposure should be reduced on the basis of the standard photometric value. The deeper the exposure, the more it is reduced. Only in this way can the brightness level of the subject be correctly restored.