"Dark part method" and "bright part method" photometry

"Dark part method" and "bright part method" photometry are your personal requirements for exposure.

Simply put:

An exposure material (including film and CCD) has a certain exposure latitude, which is far from the naked eye, and can't truly reflect the light and shade of the subject like the human eye.

Using dark light metering is a metering method in which you want to highlight the details and levels of dark parts and omit the levels of bright parts appropriately.

In the same way, using light metering is a metering method in which you want to highlight the details and levels of light and omit the levels of dark parts appropriately.

These are completely the needs of personal photography creation.