Photometry and focusing, are they all at the same point?

No, metering and focusing are only available in high-end cameras with point-to-point measurement linkage, which can achieve the same metering and focusing at the same point, but not in other cases.

Although both metering and focusing are done with the shutter half pressed, their tasks are different. The task of photometry is accurate exposure. The so-called accurate exposure means that photos can restore the light situation on the scene or realize the photographer's exposure idea. The task of focusing is to ensure that the photos are clear, or the photographer wants to be clear.

1, photometry

The metering system of digital camera generally measures the brightness of the reflected light of the subject, which is also called reflection metering.

According to the location of metering elements, metering methods can generally be divided into two ways: external metering and internal metering: (1) external metering: in the external metering mode, the optical paths of metering elements and lenses are independent. This metering method is widely used in head-up viewfinder shutter cameras with sufficient sensitivity and accuracy. Single-lens reflex cameras generally do not use this metering method.

(2) Internal metering: This metering method is based on the lens, that is, TTL metering, which is consistent with the shooting conditions and can be automatically corrected when the camera lens changes, the shooting distance changes and the color filter is added. At present, almost all single-lens reflex cameras adopt this metering method.

2. Focus

The English name of focusing is focus, which refers to adjusting the focal length when using a camera. Generally, digital cameras have various focusing modes, namely, auto focus, manual focus and multiple focus modes.

Focusing is also called aiming light, focusing. The process of changing the distance and the position of the distance through the camera focusing mechanism to make the image of the object clear is focusing.