Isn't the function of exposure locking to remember a set of exposure parameters? Explain.

Because you can refocus when you re-compose. If you use a large aperture and a shallow depth of field, when your photometric point is inconsistent with the focus, it is likely that the subject will lose focus due to the depth of field. If you use exposure locking, you can accurately refocus the composition. If you only press the shutter halfway, the focal length will be locked at the same time. Of course, full-time manual focusing can also be used to solve this problem, but it is relatively more inconvenient in the case of shallow depth of field.

In addition, for the model without point measurement linkage, if you choose to focus on a point other than the central focus, you must lock the metering before shooting. Moreover, even if the point measurement is linked, when the point is focused, the exposure value cannot be locked by half pressing the shutter, so the exposure locking is still very useful.

PS: Manual gear does not need exposure lock.