What do AF and M stand for on SLR lens, and how to use them effectively?

AF (auto focus) on the SLR lens stands for camera focus, and MF (manual focus) stands for manual focus.

SLR adopts phase focusing technology, and the camera completes ranging and focusing through the lens. The machine body drives the focusing lens group of the lens to complete the focusing action through the electronic or mechanical interface of the bayonet.

Manual focusing means that the photographer judges whether it is clear with the naked eye through the viewfinder and manually adjusts the focusing ring to complete the focusing action.

In most cases, camera autofocus can complete shooting well. But in some cases, people need help to concentrate. For example, shooting still life often needs to focus very accurately and the human eye is more reliable. Manual focusing is often faster when the contrast in the scene is too weak, too bright or too dark.

There are also special photographic effects, such as manual focusing when the shutter is open.