What method does SLR camera use to measure light?

I. Evaluation measurement (multiple measurement):

When shooting, the camera divides the image into several areas for photometry, and then calculates the most appropriate average exposure required for the whole picture to ensure accurate exposure. The average metering mode is mainly suitable for objects with no strong contrast between the shooting object and the background, and the brightness difference is relatively flat. Multi-zone evaluation photometry is the most advanced intelligent photometry method at present, and it is a kind of judgment that simulates the uniform or uneven illumination that the human brain often encounters when shooting. Even people who are not familiar with photometry can generally get films with more accurate exposure in this way.

Applicable environment: group photos, family photos and general scenery photos. ?

Second, the central key average measurement (part of the central measurement)

Average the photometry of the whole image, but focus slightly on the central object. The central focus average metering mode is a very reliable metering mode, which is suitable for almost all subjects. To sum up, it is necessary to choose the central average metering system to shoot the content that needs to show the main body, and at the same time take into account the overall exposure.

Application environment: personal photos, special scenery photos. ?

Three, the center point measurement (that is, "fixed point measurement"):

Spot photometry can only accurately measure the light in a small area, and the brightness of the scenery outside the area has no influence on photometry, so the photometry accuracy is very high, and its main purpose is to measure the light in a specific small area in the distance.

If the contrast between the subject and the background is large, spot metering, such as backlight shooting, can be considered.

Application environment: stage photography, personal art photos, special story photos, etc.

Different metering modes lead to different imaging effects. Not every photo can strictly adjust the metering mode, and it is possible that the beauty will disappear in the blink of an eye when you adjust it. However, some photos also need to adjust the metering mode, otherwise it will be a mess, and we must learn to master and use it flexibly in practice.